{"Bibliographic":{"Title":"Environmental Research Laboratories Programs and Plans","Authors":"","Publication date":"1992","Publisher":""},"Administrative":{"Date created":"08-20-2023","Language":"English","Rights":"CC 0","Size":"0000674211"},"Pages":["QC\n807.5\n.E58\n1992/\n1993\nEnvironmental Research Laboratories\nPrograms and Plans\nFY 1992 Programs and\nFY 1993 Plans\nATMOSPHERIC\nAND\nNOAA\nS\nGolden\nDEPARTMENT\nOF\nU.S. Department of Commerce\nNational Oceanic and Atmospheric Administration\nEnvironmental Research Laboratories","QC\n807.5\nE58\n1992/93\nEnvironmental Research Laboratories\nPrograms and Plans\nFY 1992 Programs and\nFY 1993 Plans\nDecember 1992\nLIBRARY\nDEPARTMENT OF\nMAR 0 5 1993\nN.O.A.A.\nU.S. Dept. of Commerce\nSTATES\nOF\nU.S. Department of Commerce\nNational Oceanic and Atmospheric Administration\nEnvironmental Research Laboratories\nSilver Spring, Maryland\nAlan R. Thomas, Acting Director","NOTICE\nMention of a commercial company or product does not constitute an endorsement by NOAA\nEnvironmental Research Laboratories. Use for publicity or advertising purposes of information from\nthis publication concerning proprietary products or the tests of such products is not authorized.\nFor sale by the National Technical Information Service, 5285 Port Royal Road\nSpringfield, VA 22061\nii","Environmental Research Laboratories\nThe mission of the Environmental Research Laboratories (ERL) is to conduct an integrated program\nof fundamental research, related technology development, and services to improve understanding and\nprediction of the geophysical environment comprising the oceans and inland waters, the lower and upper\natmosphere, the space environment, and the Earth.\nCONTENTS\n1\nIntroduction and Summary of ERL Research\n11\nOffice of the Director\n13\nAtlantic Oceanographic and Meteorological Laboratory\n27\nPacific Marine Environmental Laboratory\n41\nGreat Lakes Environmental Research Laboratory\n57\nGeophysical Fluid Dynamics Laboratory\n67\nForecast Systems Laboratory\n81\nNational Severe Storms Laboratory\n95\nWave Propagation Laboratory\n107\nClimate Monitoring and Diagnostics Laboratory\n121\nAir Resources Laboratory\n135\nAeronomy Laboratory\n151\nSpace Environment Laboratory\n163\nJoint Institutes\nCooperative Institute for Research in Environmental Sciences\n164\n173\nCooperative Institute for Research in the Atmosphere\nCooperative Institute for Mesoscale Meteorological Studies\n178\nCooperative Institute for Limnology and Ecosystems Research\n188\nCooperative Institute for Marine and Atmospheric Studies\n198\n208\nJoint Institute for Study of the Atmosphere and Ocean\n215\nJoint Institute for Marine and Atmospheric Research\n219\nAppendix: Acronyms and Initialisms.\niii","These are highlights of Laboratory accomplishments and abbreviated summaries of immediate\nobjectives. More comprehensive and detailed descriptions of activities, results, and plans may be found\nin the Laboratories' annual reports (which may be obtained directly from the Laboratories) and in the\nopen literature. Interested readers are referred to the annual Environmental Research Laboratories\nPublication Abstracts.\niv","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nENVIRONMENTAL\nRESEARCH\nLABORATORIES\nThe Environmental Research Laboratories (ERL) of NOAA's Office of Oceanic and Atmospheric Research\nare headquartered in Silver Spring, Maryland. ERL includes major units throughout the United States:\nAeronomy Laboratory (AL)\nBoulder, Colorado\nAtlantic Oceanographic and Meteorological Laboratory (AOML)\nMiami, Florida\nAir Resources Laboratory (ARL)\nSilver Spring, Maryland\nClimate Monitoring and Diagnostics Laboratory (CMDL)\nBoulder, Colorado\nForecast Systems Laboratory (FSL)\nBoulder, Colorado\nGeophysical Fluid Dynamics Laboratory (GFDL)\nPrinceton, New Jersey\nGreat Lakes Environmental Research Laboratory (GLERL)\nAnn Arbor, Michigan\nNational Severe Storms Laboratory (NSSL)\nNorman, Oklahoma\nPacific Marine Environmental Laboratory (PMEL)\nSeattle, Washington\nSpace Environment Laboratory (SEL)\nBoulder, Colorado\nWave Propagation Laboratory (WPL)\nBoulder, Colorado\nIn addition, seven institutes administered jointly by ERL and universities undertake research for ERL. ERL\nalso sponsors research through contracts and grants to universities, state and federal agencies, and private\nenterprise. Many ERL research efforts rely on the cooperation of other NOAA elements, including the\nNational Weather Service (NWS), National Environmental Satellite, Data, and Information Service\n(NESDIS), National Ocean Service (NOS), National Marine Fisheries Service (NMFS), and Office of NOAA\nCorps Operations (ONCO).\nERL's program includes fundamental research to develop technology and improve NOAA services to the\npublic. Samples of research results and applications are Doppler radar technology (to improve tornado\ndetection and warnings), mathematical models (to predict climate and ocean variations and to improve\nhurricane forecasting), ocean current forecasts (to minimize ship operation costs), cooperative fisheries and\noceanography studies (to improve prediction and management of fisheries stocks), and solar activity forecasts\n1","AL\nARL\nAOML\nCMDL\nFSL\nGFDL\nGLERL\nNSSL\nPMEL\nSEL\nWPL\nWeather\nClimate\nAir Quality\nOcean and\nGreat Lakes\nSolar-\nTerrestrial\n(to protect astronauts and preserve communications efficiency). Examples of cooperative programs to transfer\ntechnology to the private sector include the development of commercial wind profiling systems, coastal\ncurrent radars, and workstation applications software. Users of ERL research results include the atmospheric,\nmarine, and space research communities; NOAA service components (NWS, NOS, NESDIS); other federal\nagencies; state and local governments; and the private sector.\nERL is a key element in NOAA's response to major emerging national environmental programs, including\nClimate and Global Change, Coastal Oceans, and Stormscale Operational and Research Meteorology\n(STORM). A broad spectrum of research throughout ERL contributes to these programs.\nERL is a major contributor to the development of national and international environmental policy. Research\napplicable to policy development includes explaining the cause of the Arctic ozone hole and supporting the\nscientific measurements that led to the Montreal Protocol to reduce the production of CFCs; monitoring the\ngrowth rates of greenhouse gases to determine if regulatory action to limit fossil fuel usage is justified; and\nstudying the causes of high levels of rural ozone to determine why rural and urban air quality standards cannot\nbe met with the same regulatory strategies.\nThe ERL program embraces studies relating to the oceans and Great Lakes, the lower and upper\natmosphere, and the solar-terrestrial environment. Studies and services focus on five subject areas: Weather,\nClimate, Air Quality, Ocean and Great Lakes, and the Solar-Terrestrial environment.\nThe following summary of ERL research is organized by these subject areas. Succeeding sections discuss\nthe accomplishments and plans of the Laboratories and Joint Institutes. The Appendix lists acronyms and\ninitialisms used in all sections.\nWEATHER\nWeather research concerns observational systems; data acquisition, management, analysis, and display\nsystems; severe storm prediction, including flash floods, hail, tornadoes, and wind storms; and hurricane\nprediction. The goal of ERL weather research is to provide the theoretical framework, scientific under-\nstanding, and technology to assure the success of NOAA's program to modernize the Nation's weather\nservices of the 1990s. Significant ERL contributions to upgrading the NOAA weather services include the\ndeveloping the next generation operational weather observing systems, prototyping new forecaster worksta-\ntions, improving forecasting by translating better understanding of severe weather events into forecast tools,\n2","Environmental Research Laboratories\nand transferring improved forecast models to operational units. Major elements of ERL's weather research\nare conducted by AOML, FSL, GFDL, NSSL, and WPL. Major 1992 accomplishments and 1993 plans for\nweather research include the following.\nAOML omega dropwindsondes dropped from a NOAA WP-3D aircraft were used to obtain data to\nobserve the steering currents of Hurricane Andrew, which struck southern Florida and Louisiana in\n1992. AOML had developed software for real-time processing of the data on an airborne computer\nworkstation during a flight, allowed real-time transmission to the National Hurricane Center. The\ntransmitted data were included as input to AOML's track and intensity prediction models to create\nforecasts of Andrew, and the predictions proved to be extremely accurate.\nIn FY 93, a new version of the VICBAR hurricane model will be used on the season's storms, and\nafter the season, the VICBAR forecast errors will be evaluated.\nUsing a hurricane model, GFDL studied a series of idealized experiments with improved treatment\nof radiation and surface conditions to examine why tropical cyclones do not form over land surfaces\nsuch as a tropical rainforest. It was determined that the small heat capacity and thermal conductivity\nof the soil hindered storm formation.\nFY 93 studies will investigate the effects of tropical cyclones on the evolution of the surrounding\nenvironment. These studies will improve the understanding of the interactions between cyclones and\nthe synoptic scale that determine why cyclones do or do not intensify into more intense tropical\nstorms such as hurricanes.\nFSL accepted all 30 wind profilers, along with their communications links, that were installed by\ncontractors. Data from 29 production wind profilers and one prototype system are routinely being\nsent to the NWS Telecommunications Gateway for distribution to forecast offices and the private\nmeteorology community, and to Unidata for distribution to university and other researchers.\nSix-minute and hourly data on tape are sent to the National Climatic Data Center (NCDC) for retrieval\nand permanent archival.\nThe Wind Profiler Demonstration Network data will be supplied to internal and external users,\nimprovements in data quality for the lowest 3 km will be implemented, and the Radio-Acoustic\nSounding System (RASS) with temperature capability will be operated and assessed at some network\nsites during 1993.\nA major focus in FSL has been the research and development of the Local Analysis and Prediction\nSystem (LAPS), which provides real-time, three-dimensional, local-scale analyses and short-range\n(0-12 hour) prediction of the atmosphere for a typical NWS Forecast Office (NWSFO). The system\nis designed to fully incorporate all new observational technologies (e.g., Doppler radar, wind profiler,\nautomated surface observations, digital satellite observations, and aircraft observations) on a work-\nstation that will be available at local NWS weather offices. The latest prototype of LAPS is being\nevaluated at the NWSFO in Denver, Colorado.\nIn FY 93, quality control methods to verify and improve the LAPS analysis will be developed. Daily\nshort-range weather predictions using the Colorado State University RAMS model will be initialized\nwith LAPS, and the development of a full four-dimensional data assimilation (4DDA) scheme will\nbegin. A forecast exercise will be run during the summer of 1993 to test the 4DDA scheme and to\nmeasure the progress of LAPS against a baseline performance measure developed during an FY 92\nexercise.\nNSSL completed an unprecedented detailed radar study that examined many squall line storms at\ndifferent times during their evolution. A class of squall lines was discovered that featured a solid\nleading edge radar echo instead of discrete cell echoes. This type of squall line was observed to persist\nfor many hours in a steady configuration, and is characterized by updrafts tilting very strongly\nrearward with height. These findings prompted a theoretical examination of the role of the change\n3","of wind with height in a squall line's environment. The theoretical studies established that stronger\nincreases of wind with height (blowing along the direction of squall line movement) ahead of the\nsquall line favor longer-lived systems, and that the optimal wind structure depends partially on the\nstrength of the cold storm outflow.\nIn FY 93, squall line structure and longevity studies will continue, and other features of storms with\nsolid leading edge echoes will be determined. Understanding these storms is important to the weather\nservices modernization and the improved warning services that will be available with Doppler radars.\nNSSL used various data sets gathered during a 1990 field program in the southwestern United States\nand northwestern Mexico to study and document a wide variety of mesoscale and large-scale weather\nsystems and processes. The large-scale setting that bring severe thunderstorms to central Arizona\nwas documented, and three distinct patterns were identified. A Geostationary Operational Environ-\nmental Satellite (GOES) monsoon raininess index was developed that has distinct advantages over\nthe historical approach, which uses climatological rainfall reports from surface stations. The new\nindex was generated with, and will be utilized at, the NWSFO in Phoenix, Arizona.\nIn 1993, NSSL's on-going role of translating research results into improved NWS forecasts will\ncontinue. small collaborative exercise will gather data in central Arizona and northwestern Mexico.\nThe exercise will also assess WSR-88D performance in the Phoenix area. Efforts to further\ncharacterize the three distinct patterns over the area will continue, and additional severe weather\nforecast algorithms will be developed for use in the southwestern United States.\nWPL continues to push back the frontiers of atmospheric sensing with a new concept for profiling\natmospheric winds and turbulence, new lidar systems for studying clouds, and an improved RASS.\nIn FY 92, the Laboratory used a network of five lower-tropospheric profilers to gather data in the\nfield phase of the STORM Fronts Experiment System Test (STORM-FEST) These data will be used\nto evaluate recent analyses of the spatial and temporal sampling required for profiler networks.\nComparing tower-mounted turbulence sensors and a boundary-layer RASS to measure vertical heat\nflux revealed significant differences in the heat flux spectra produced by these two methods. These\ndifferences must be resolved before RASS systems are implemented in the Wind Profiler Demon-\nstration Network.\nIn FY 93, WPL will complete the analyses of two midlatitude winter storms using data from the\nSTORM-FEST field experiment to study the structure, evolution, and coupling of fronts, jets, and\nprecipitation. The nonstationarity of mountain waves will be explored through additional case studies\nand comparisons of simulations with a two-dimensional, nonhydrostatic numerical models to\nquantify the effects of the changing wave environment on wave structure.\nCLIMATE\nClimate research is performed by most of the Laboratories. The goals of this research are to recognize,\ndiagnose, analyze, understand, and predict large-scale and regional changes in the oceans and atmosphere.\nSignificant 1992 climate research accomplishments and 1993 plans include the following.\nAOML's focus in the Atlantic Climate Change Program was the completion of a two-ship survey\nwith direct measurements and indirect methods of estimating heat transport in the deep oceans.\nPreliminary results suggest that new techniques of obtaining absolute velocity profiles in the total\nwater column contribute significantly to studies of heat flux. In the Pacific region, AOML activities\nfocused primarily on observations related to research on the El Niño-Southern Oscillation (ENSO).\nMore than 200 satellite-tracked drifting buoys were used to measure sea-surface temperature and\n4","Environmental Research Laboratories\ncurrents. Geodetic Satellite altimeter data were used with the drifing buoys and pressure gauge data\nto investigate the causes of large sea-level variations at Clipperton Island in the eastern Pacific Ocean.\nIn FY 93, the data collected in the 1992 Atlantic cruise will be analyzed by investigators from the\nfour academic institutions that took other observations during the cruise. Emphasis will be given to\nthe robustness of heat flux estimates from single sections, new technologies for estimating deep\nvelocities, and the distribution of deep water masses in the Atlantic. In the Pacific, efforts to establish\nan operational drifting buoy array, quality control of the drifting buoy data sets, oceanographic\ninterpretation of the data, and evaluation of the observing system will be the highest priority.\nGFDL completed a 1000-year integration of a coupled ocean-atmosphere model. The analysis\nindicated that there is substantial variability of the 40-50 year thermohaline circulation in the North\nAtlantic, and the surface temperature variability tends to be larger and more persistent near deep and\nintermediate water formation.\nIn FY 93, analysis of low-frequency variability in the coupled model of the atmosphere-ocean system\nwill continue. Special emphasis will be placed on the role of the oceans in the interdecadal variability\nof climate. To explore how the atmosphere responds to perturbations in sea-surface temperature, a\nseries of low-resolution integrations will be performed with the low-resolution atmospheric model\nusing both realistic and idealized geometries.\nA critical issue in global change is the effect of warming on the hydrology of the Great Lakes basin,\nand specifically on net basin water supplies. Of particular concern is how various climate regimes\nmay affect variability from year to year in net basin water supplies and in lake levels. In FY 92,\nGLERL selected two scenarios that represent potential future climates in the Great Lakes basin: \"hot\nand dry\" and \"hot and wet.\" These climatologies will be applied to the Great Lakes area, and the\nresultant hydrological effects on the Great Lakes will be evaluated. In addition to temperature-\nmoisture effects, snowfall-Northern Hemisphere circulation correlations may be important in global\nchange studies. To address this issue, monthly, yearly, and period of record snowfall maps are being\ncompiled and quantitative relationships between circulation patterns will be studied.\nIn FY 93, the Great Lakes hydrological models of the \"hot and dry\" and \"hot and wet\" scenarios will\nbe run. The effects of precipitation, run-off, evaporation, and lake levels for these two regimes will\nbe analyzed. The analysis of the extreme snowfall-Northern Hemisphere circulation correlations will\nbe completed, and an analysis of atmospheric circulation anomaly and Great Lakes ice cover anomaly\nwill begin.\nWPL climate studies were highlighted by 8-mm-radar observations with lidars, radiometers, and\nother sensors of nonprecipitating clouds to infer the microphysical structure and radiative features\nof cirrus clouds in FIRE II and marine stratus clouds in ASTEX. These multiagency studies will\nclarify the role of clouds in climate change.\nIn FY 93, WPL will complete the analyses of the FIRE II and ASTEX experiments, and collaborate\nwith cirrus and marine stratus cloud modelers in NOAA and universities to incorporate ice water flux\ninto cirrus models and vertical velocity statistics in marine cloud models.\nIn FY 92, CMDL greenhouse monitoring programs continued; carbon dioxide was monitored at all\nfour baseline observatories, methane at Barrow and Mauna Loa, and carbon monoxide at Barrow.\nVertical profiles of carbon dioxide from a very tall tower in North Carolina and vertical profiles via\nflasks aboard private aircraft were taken to better characterize the contribution of terrestrial ecosys-\ntems to the global carbon budget and to better define the concentrations of methane and carbon\nmonoxide in the vertical. Analysis of flask methane data from 1983 to 1991 revealed that the rate of\nincrease of atmospheric methane is slowing, whereas carbon dioxide increase remains at approxi-\nmately 0.4% per year.\n5","CMDL satellite studies in FY 92 compiled and examined NOAA polar-orbiting data from the last 9\nyears to determine atmospheric water vapor content. Monthly mean images appear highly correlated\nwith large-scale overturning circulations in the tropics and subtropics. Analysis of the time-space\nvariance of these data showed that interannual changes in water vapor are linked to large-scale\ncirculation changes during an ENSO event. Results from studies on the application of satellite-\nderived sea-surface temperatures in global climate monitoring show that these temperatures continue\nto be affected by large volcanic aerosols in the atmosphere from eruptions during the last 10 years,\nparticularly from El Chichon and Mount Pinatubo.\nIn FY 93, different satellite-derived products of water vapor will be examined and compared. Work\nwill begin with the European Space Agency to examine data from a new satellite that should provide\nimproved estimates of sea-surface temperature regardless of atmospheric aerosol content.\nARL updated the record of global tropospheric and low-stratospheric temperatures that now extends\nfrom 1958 through the summer of 1992. Tropospheric temperatures for the first three seasons of 1992\nwere the coldest since 1976. After adjustment for the influence of ENSO, the first three seasons of\n1992 were the coldest since 1964, the year after the Agung eruption. The sudden drop in global\ntemperature is undoubtedly related to the eruption of Mt. Pinatubo in 1991.\nAL continued wind observations at Christmas Island for the Tropical Ocean Global Atmosphere\n(TOGA) program. These observations, which extend over the last 5 years, are used operationally by\nthe world meteorological centers and are published in monthly summaries in two climate bulletins.\nDuring the last year, the five-site Trans-Pacific Profiler Network was completed with the installation\nof a profiler at Biak, Indonesia, in March 1992. Comparison of the observed Christmas Island winds\nduring the past year with the 5-year averages shows the clear influence of El Nino. Lower\ntropospheric winds and substantially weaker than normal, occasional episodes of lower tropospheric\nweserlies have been seen since late 1991, and upper tropospheric winds have been much weaker than\nnormal.\nIn FY 93, AL will continue to operate the network, transmit 6-hourly data via satellite to the scientific\ncommunity, and archive the high-resolution data on optical disks. Plans also include participating\nin the field phase of the TOGA Coupled Ocean-Atmosphere Response Experiment (COARE), and\nbeginning a detailed analysis of intraseasonal variability of the atmospheric circulation within the\nCOARE large-scale domain.\nAIR QUALITY RESEARCH\nERL air quality research is led by GFDL, AL, ARL, and WPL. The goal of this research is to understand\nand predict the health of the atmosphere, thus providing policy makers with the scientific information needed\nto reduce harmful effects. The main focuses are ozone and acid rain. Major 1992 accomplishments and 1993\nplans include the following.\nThe GFDL Global Chemical Transport Model (GCTM) was used to evaluate the behavior of\nchemically reactive nitrogen components as transported species. The experiment revealed several\nnew insights: about 70-75% of fossil fuel emissions are deposited near their source regions, and the\nremainder are exported to adjacent ocean basins; fossil fuel sources dominate the observed nitric acid\nsurface deposition in the extratropical North Atlantic; and fossil-fuel source has only a minor impact\non reactive nitrogen components in the Southern Hemisphere and remote tropics.\nIn FY 93, reactive nitrogen simulations will be carried out in the GCTM for multiple species with\nall the nitrogen sources and hydrocarbon effect included, and the photochemistry of biomass reactive\n6","Environmental Research Laboratories\nnitrogen emissions and ozone over the tropical ocean will be examined in the context of regional\ntransport.\nARL completed calculations of sulfate wet deposition and air concentrations for 1989. Two sets of\ncalculations used the Hybrid Single Particle Lagrangian Integrated Trajectories transport and\ndispersion model with a nonlinear chemistry module. One used the Nested Grid Model (NGM)\npredicted precipitation fields and the other used measured precipitation values in computing wet\ndeposition. In general, the NGM predictions were an adequate substitute for the measured data when\nseasonal (or longer) averages are desired.\nIn FY 93, the deposition modeling efforts will be expanded to include nitrogen chemistry and more\ndetailed spatial structure by incorporating major point source plumes with certain regions. Amodeling\nstudy also will be conducted to compute ground-level air concentrations from pollutants from the\nKuwaiti oil fires.\nAL completed measurements of ozone production and transport from the North American continent\nover the Atlantic Ocean. These measurements were undertaken in response to the growing concern\nthat long-range ozone transport may influence air quality on an interhemispheric scale. The results\nindicate that, during the summer over the temperate North Atlantic, the quantity of ozone generated\nphotochemically from anthropogenic emissions on the North American continent exceeds that\ninjected from the stratosphere.\nIn the summer of 1993, AL will participate in a new intensive North Atlantic Regional Experiment\nto better determine the budget of ozone in the North Atlantic troposphere utilizing both ground-based\nand airborne sensor measurements.\nWPL completed two experiments related to air quality research. Lidar measurements obtained in\nFebruary near the Department of Energy's Rocky Flats plant in Colorado were analyzed to study the\ninteractions between the thermally forced exit jets from nearby canyons and larger-scale process.\nLidar observations of the sea breeze off the California coast showed the vertical and horizontal growth\nof the sea-breeze layer in the morning, but no compensatory return flow.\nIn FY 93, lidar techniques will be used to study atmospheric boundary-layer processes through\nanalysis of observations obtained at Rocky Flats and the Grand Canyon, and intercomparison\nexperiments will be run in preparation for the upcoming Boreal Ecosystem-Atmosphere Study.\nOCEAN AND GREAT LAKES RESEARCH\nERL studies of the oceans and Great Lakes focus on prediction, ecosystem assessment, and resource\nassessment. Principal research is conducted by AOML, PMEL, GLERL, and GFDL. Significant accomplish-\nments for 1992 and plans for 1993 include the following.\nAOML conducted a series of cruises along the western Louisiana shelf in the Gulf of Mexico during\nthe summer to determine the effects of anthropogenic input on the the Mississippi-Atchafalaya River\noutflow area. This research was in support of the Nutrient Enhanced Coastal Ocean Productivity\ncomponent of the NOAA Coastal Ocean Program. Researchers determined the extent of the hypoxia\non the Louisiana shelf. All samples collected during the four NECOP cruises completed during\nFY 91-92 were analyzed and entered into the NECOP data base.\nIn FY 93, winter, spring, and summer cruises are planned in the Mississippi-Atchafalaya River\noutflow area to measure the seasonal variations in the anthropogenic input, determine the dynamics\nof hypoxia on the western Louisiana shelf, and map zooplankton distributions about the Mississippi\nplume to validate the statistical predictions made from prior data.\n7","The first full year of the Bering Sea Fisheries Oceanography Coordinated Investigations (FOCI) was\ncompleted as a joint effort of scientists from PMEL, five universities, the Alaska Fisheries Science\nCenter, and the Russian Research Institute of Marine Fisheries and Oceanography and Pacific\nResearch Institute of Fisheries and Oceanography. The goal of the program is to provide scientific\ninformation to reduce uncertainty in decisions of resource management concerning the abundance\nof walleye pollock. Four major data sets were obtained from 112 conductivity, depth, temperature\nstations in both Russian and U.S. waters; five current moorings in Amchitka Pass, Near Strait, and\non the northern continental slope; 25 satellite-tracked drifting buoys; and the shipboard Acoustic\nDoppler Current Profiler operating on a dedicated transect. A major finding from the cruise was that\nthe Alaskan Stream was not flowing into the Bering Sea through Near Strait. This anomaly started\nin fall 1990 and persisted through at least 1991.\nIn FY 93, PMEL will conduct an echo integration-midwater trawl survey of the Bering Sea to assess\nthe distribution and abundance of walleye pollock, and will continue to work on molecular and\nchemical techiques for stock separation to determine if there are separate stocks of pollock through\nthe Bering Sea basin.\nPMEL continued to develop techniques to use the T-phase event detection system, the U.S. Navy's\nIntegrated Underwater Surveillance System (IUSS) long-range acoustic surveillance tool, to detect\nand study underwater hydrothermal activity while it is in progress. The studies in FY 92 show that\nthe volcanic system off the northwest coast of North America is at least two to three orders of\nmagnitude more seismically active than was observed through other monitoring techniques.\nIn FY 93, PMEL plans to continue to develop procedures and software to collect, process, and\nevaluate T-phase signals, and to collaborate with the U.S. Navy in developing civilian use of IUSS\nhydrophone arrays for scientific purposes.\nGLERL is working to identify and understand changes in the lower food web of Saginaw Bay that\nhave resulted from the invasion of the zebra mussel, to construct a model of the carbon flow in the\nsystem, and to monitor changes in abundance and distribution of the mussel in the bay. In FY 92,\nsamples were collected monthly at 26 stations beginning in April, zooplankton grazing rates were\ndetermined at six of the stations, and experiments to determine filtering rates of zebra mussels were\nconducted.\nIn FY 93, coordination of sampling with participants from federal and state agencies and academic\ninstitutions, monthly monitoring at the 26 stations, sampling of mussels at sites in Lake St. Clair and\nSaginaw Bay, and analysis for weight, lipids, carbon, and nitrogen content will continue.\nIn FY 92, GLERL investigated a new methodology to measure the assimilation efficiency of organic\ncontaminants from ingested sediments. Examination of the extent of exposure for benthic organisms\nexposed to differing representation of sediment, whole sediment, interstitial water, and elutriates,\nsuggests that the organisms in the whole sediment accumulate more compound and the contaminant\nin the sediments is much more available.\nFY 93 plans include examining the time course of solute extraction from sediments as a function of\nsupercritical fluid density, solvent modifers, and temperature; and comparing the time course of\nextraction of laboratory-dosed, isotopically labeled compounds with that of compounds from\nfield-contaminated sediments.\nGFDL developed a new hypothesis to explain the unique character of the Atlantic overturning\n\"conveyor belt\" circulation. Mechanical forcing by westerly winds of the Southern Oceans may be\nequally as important in forcing pole-to-pole overturnings as the effect of thermohaline density\ngradients.\n8","Environmental Research Laboratories\nFY 93, a 1° by 1° longitude model of the world ocean will be developed to explore the hypothesis\nIn\nabout the Atlantic overturning conveyor belt circulation that has already been tested in lower\nresolution models.\nSOLAR-TERRESTRIAL RESEARCH AND SERVICES\nThe ERL solar-terrestrial program is unique because it contains both research and service components and\nbecause the major user of the research component is the internal service component. The following are major\naccomplishments in 1992 and plans for 1993.\nSEL formed a customer focus group to gather and consolidate information on users of SEL products\nand to evaluate user needs. Current information on users was reviewed for inclusion in a customer\ndata base. Prelimary statistics on users and their needs were prepared, and results were published. In\nFY 93, SEL will continue to improve information on users and their needs, and develop a marketing\nplan based on those needs. A survey to ask users how they obtain SEL products and services, an\nanalysis of current services and products, and a newsletter and other educational material will be\ncompleted.\nConstruction was begun of the Solar X-ray Imager, funded by the U.S. Air Force, to fly on a future\nGOES. This imager is expected to provide vastly improved observations of solar conditions that can\naffect the Earth's environment.\nIn FY 93, SEL will continue to assist NASA in monitoring the X-ray imager implementation by their\ncontractors, continue to obtain limited numbers of X-ray images from the Japanese Yohkoh space-\ncraft, and continue to work with NESDIS to implement the imager on the new GOES.\nSEL supervised the Space Environment Monitor (SEM) contract for the systems scheduled to fly on\nthe NOAA-K, -L, and -M spacecraft in the mid-1990s. The engineering model was fabricated, and\nthe environmental test began. The ground support equipment was fabricated and software was\nwritten and tested.\nIn FY 93, the contract supervision for SEM for TIROS will continue. The delivery of the engineering\nmodel, the protoflight model, and the first flight model of the TIROS SEM-2 is expected. The plan\nfor the procurement of future SEM instruments for NOAA and European satellites will be developed.\n9","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nOFFICE OF THE DIRECTOR\nSilver Spring, Maryland\n(301) 427-2458\nAlan R. Thomas, Acting Director\nRobert J. Mahler, Deputy Director\nThe Director, assisted by the Deputy Director, establishes policy and manages the overall activities of the\nEnvironmental Research Laboratories (ERL). This includes the NOAA-university cooperative research\nprograms, the NOAA-National Research Council Resident Research Associateship Program, and editing\nservices. The Budget Office provides budget analysis and execution, and financial and management\ninformation in support of the Laboratories. Program Development and Coordination (PDC) provides advice\nand support in areas of policy, program planning, budget formulation and analysis; program coordination and\nreview; and implementation of management decisions.\n11","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nATLANTIC OCEANOGRAPHIC AND METEOROLOGICAL\nLABORATORY\nMiami, Florida\n(305) 361-4300\nHugo F. Bezdek, Director\nThe Atlantic Oceanographic and Meteorological Laboratory (AOML) conducts basic and applied research\nprograms in oceanography, ocean and atmospheric chemistry, and tropical meteorology. Oceanographic\ninvestigations center on fluxes of energy, momentum, and materials through the air-sea interface; the transport\nand composition (thermal and chemical) of water and sediments in the Pacific and Atlantic Oceans and Gulf\nof Mexico; the effects of the ocean environment on fisheries populations; and hydrothermal processes of\nmineralization at seafloor-spreading centers. Atmospheric chemistry investigations study the origin, exist-\nence, and potential effect of various substances in the atmosphere on global climate. Meteorological research\nis carried out to improve the description, understanding, and prediction of hurricanes.\nThe research programs are enlarged by the Cooperative Institute for Marine and Atmospheric Studies\n(CIMAS), a joint enterprise with the Rosenstiel School of Marine and Atmospheric Science of the University\nof Miami. CIMAS enables NOAA and university scientists to collaborate on problems of mutual interest\nand facilitates the participation of visiting scientists.\nCLIMATE AND AIR QUALITY\nClimate research at AOML focuses on aspects of ocean heat transport and storage in relation to interannual\nand longer term variations of weather and climate. The emphasis is on collection and analysis of oceano-\ngraphic data, the ultimate goal being to improve forecasting. Improvement of skill in the use of coupled\nocean-atmosphere models is essential to achieving this goal. AOML is also a major participant in the\ndevelopment of ocean observing systems for climate and global change issues, and has accepted responsibility\nfor some of the required data management activities. Participation in these activities has led to a close\nassociation with the international World Ocean Circulation Experiment (WOCE).\n13","Activities are currently concentrated on problems associated with two different time scales of climate\nvariations. The shorter of these, and the best recognized example, is the El Niño-Southern Oscillation\n(ENSO) phenomenon, which is manifested most clearly in the tropical Pacific Ocean but has global\nimplications. Accordingly, AOML is a major participant in the Equatorial Pacific Ocean Climate Studies\n(EPOCS) and Tropical Ocean Global Atmosphere (TOGA) programs in the tropical Pacific. These programs\nare in the process of installing an extensive array of tethered buoys across the equatorial Pacific. The data\ngathered from the current meters and meteorological instruments attached to these buoys are being used to\npredict and monitor the ENSO phenomenon.\nOn longer time scales, the ocean circulation of heat from low latitudes to high latitudes is believed to be\none of the critical processes governing the climate of the Earth and its variations. Most evidence indicates\nthat the Atlantic Ocean is particularly important in this process. The influence of Atlantic circulation on\nclimate is a major component of NOAA's Climate and Global Change Program. AOML scientists have had\nleading role in developing plans for this research program, and participate extensively in its implementation.\na\nThe Radiatively Important Trace Species (RITS) program has been involved for several years in a sequence\nof experiments to better understand the biochemistry of the air adjacent to the sea surface, the marine boundary\nlayer. To that end, the AOML field program within RITS has been organized around cruises in the equatorial\nAtlantic (1986), equatorial Pacific (1987, 1990), South Atlantic (1991), and North Atlantic (1992). This field\nprogram has focused on understanding the chemical and biological interactions of ozone, carbon monoxide,\nactive nitrogen species, and sulfur gases.\nThe Ocean Carbon project of the Climate and Global Change Program is a large-scale investigation of\ncarbon chemistry and nutrient dynamics of the eastern equatorial Pacific. The study is part of the U.S. Joint\nGlobal Ocean Flux Study (JGOFS). The NOAA component involves investigators of three NOAA labora-\ntories, AOML, Geophysical Fluid Dynamics Laboratory (GFDL), and Pacific Marine Environmental Labo-\nratory (PMEL), and investigators from six universities.\nThe follow-on research and engineering program to the Heard Island Feasibility Test (HIFT) is called the\nAcoustic Thermometry of Ocean Climate (ATOC) program. HIFT successfully ensonified the Atlantic Ocean\nusing a widely spaced network of listening platforms and stations. The purpose was to determine whether\nlong-range acoustic propagation could be used to measure climatic changes in global oceans. ATOC is a\nmultiyear international program designed to monitor changes globally in ocean parameters such as tempera-\nture by installing networks of acoustic sources and receivers in all the major ocean basins. The immediate\ngoal of the ATOC program is to establish a network in the Pacific. It will have two purposes. First, it will\nresolve scientific issues that were not resolved by HIFT. These include ray-path stability and the influence\nof gyre-basin-scale variability on acoustic travel times. Second, it will be the first component of a global\nmonitoring network that will determine the extent of greenhouse warming. Present plans call for the Atlantic\nATOC network to be installed in 1994 or 1995. Ascension Island, one of the stations used in HIFT, will be\na component of the Atlantic network.\nWeather Observations Through Ambient Noise (WOTAN) is a joint program between AOML and the\nNational Environmental, Satellite, Data, and Information Service (NESDIS) to provide independent rainfall\nrate data for use in verifying open-ocean, satellite-derived rainfall rates. Several experiments were performed\nto measure the ocean acoustic noise generated by the falling rain and to interpret the noise to determine rainfall\nrates.\n14","Atlantic Oceanographic and Meteorological Laboratory\nAccomplishments FY 92\nClimate Change: Atlantic\nThe principal thrusts of AOML's seagoing research on Atlantic Climate Change were investigations of the\nwestern boundary current structure, development of approaches to estimate large scale north-south oceanic\nheat flux, monitoring of flow through the interisland passages from the Atlantic to the Caribbean, and\ncalibration cruises for the Florida Current monitoring system.\nA two-ship survey (ACCP-MB-92-04) was coordinated during August 1992 to test, with direct measure-\nments, indirect methods of estimating heat transport in the deep ocean. New techniques of obtaining absolute\nvelocity profiles in the total water column were tested, and preliminary results suggest that the new approach\nwill make important contributions to studies of heat flux.\nSeveral throughflow cruises between islands in the Lesser Antilles chain were conducted using a vessel\nfrom the Barbados government during which data were collected and transfer of technology was conducted\nSO that regional Caribbean institutions can continue the monitoring.\nCable calibration cruises in the Straits of Florida took on added importance because the inactive cable\npreviously used for monitoring the Florida portion of the Gulf Stream experienced a catastrophic failure and\nthe remaining active cable experienced more calibration jumps.\nThe Volunteer Observing Ship (VOS)/expendable bathythermograph (XBT) scientific analysis center is\noperational. Real-time XBT data were quality controlled to ensure that the vos network is operating\neffectively and that XBT data collected and archived for the Atlantic are of the highest quality. To ensure the\ncontinued effectiveness of the network, ships with large numbers of erroneous profiles during the month\nanalyzed were identified and reported to the International Global Ocean Services System (IGOSS) coordi-\nnator in Paris, France. The coordinator then contacted the appropriate ship operator to correct the problems.\nClimate Change: Pacific\nAOML activities in the Pacific region were focused primarily on observations related to research on ENSO\nphenomena. In cooperation with scientists from several other institutions and foreign countries, AOML\nscientists maintained an array of more than 200 satellite-tracked drifting buoys in the tropical Pacific to\nmeasure sea-surface temperature (SST) and currents. These buoys were a critical component for SST\nanalyses of the ENSO event in the Pacific, and the data collected proved to be of much higher quality than\nsimilar data collected using alternative methods for other oceanic regions.\nGeodetic Satellite (GEOSAT) altimeter data were used with drifting buoy data and pressure gauge data to\ninvestigate the causes of large sea-level variation at Clipperton Island. During the year, drifting buoy releases\nwere begun in the higher latitudes of the Pacific, and also in the North Atlantic for the WOCE program.\nAOML participated in the development logistics for these buoys, and established a Data Acquisition Center\nfor the new global drifting buoy array.\nAOML continued to collaborate with several agencies in Latin America to make sea level and meteoro-\nlogical observations at coastal stations, and to collect XBT data needed for the TOGA and WOCE programs\nfrom vessels of opportunity that call exclusively at South American ports. A project was begun also to\nassemble and perform quality control on a comprehensive subsurface data set for the Pacific basin.\n15","ASTEX Atlantic Cruise\nOcean Chemistry Division scientists aboard NOAA ship Malcolm Baldrige joined about 250 other\nscientists from France, England, and Germany in the international Atlantic Stratocumulus Transition\nExperiment (ASTEX) near the Azores Islands, North Atlantic Ocean. The purpose of the project was to study\nthe travel of air masses in the upper atmosphere and polluted continental regions into the area offshore, and\nto determine the process of chemical interactions and the contribution of the ocean to the air masses.\nCoordinated meteorological and chemical measurements were made on three islands, five ships, and seven\naircraft. Highlights of the portion of the project conducted aboard the Malcolm Baldrige were 1) continuous\nand simultaneous sampling during several 24-h cycles of all six sulfur species relevant to climate alteration;\n2) short time-base (4-h) measurements of particle size distributions of methanosulfonate (MSA), non-sea-salt\nsulfate, and other ionic species; and 3) vertical profile measurements of dimethylsulfide (DMS), the dominant\nmarine source of sulfur in the atmosphere, up to the cloud base using a series of tethered balloon flights to\naltitudes of up to 1 km.\nThese chemical and meteorological measurements will be used to develop a description of the sources of\nboundary layer ozone and of specific sulfur and nitrogen species. Particle size distribution data will be used\nto verify observations made in the equatorial Pacific in 1990 that MSA preferentially condenses on preexisting\nparticles rather than creating new particles. In addition, these data will be used in conjunction with\nsimultaneous aerosol water content measurements as a function of particle size, made during the cruise by\nscientists from NOAA's Air Resources Laboratory (ARL), to verify models of hygroscopic particle growth\nin the marine atmosphere.\nEPOCS/Carbon Dioxide Equatorial Pacific Cruise\nThis cruise combined, for the first time, the requirements of these two diverse projects and efficiently\nutilized ship time to complete an extremely productive cruise. EPOCS mooring deployments planned along\nfour meridians, 110°W, 125°W, 140°W, and 170°W, and between 10°N and 10°S in the equatorial Pacific,\nprovided a useful sampling grid for the carbon dioxide project.\nIntensive sampling was performed within the top 1000 m at intervals ranging from 2° to 0.25° latitude\nwithin the grid. Between CO2 sampling operations, EPOCS mooring operations were conducted, which\nprovided time for CO2 personnel to catalog and process samples. Parameters collected include total inorganic\ncarbon, partial pressure of carbon, pH, alkalinity, chlorophyll, productivity, oxygen, salinity, dissolved organic\ncarbon, particulate organic carbon, natural thorium, and nutrients. More than 2000 samples were collected\nfor many of the parameters, and all planned mooring operations were completed. Preliminary values indicate\nhigh-quality analyses for most of the parameters sampled. The tight sampling grid will facilitate study of\nmedium-scale structures in this complex hydrographic region.\nPreliminary results indicate that the weak El Niño of 1991-1992 had a significant influence on the currents\nand carbon chemistry in the study area. The undercurrent was about one-half its normal strength at 110°W\nand at 125°W. Carbon dioxide values in surface water particles were lower than expected, suggesting that\nthe carbon flux to the atmosphere might have decreased as much as 40%. Surface total carbon dioxide and\nnutrient values also were lower than observed during non-El Niño years.\nDevelopment of a vos CO2 Sampling System\nThe partial pressure difference of CO2 between the atmosphere and ocean is now measured with AOML\nequipment on all cruises of Malcolm Baldrige. The equipment is maintained by ship's personnel. The first\n16","Atlantic Oceanographic and Meteorological Laboratory\ncruise in the \"unattended\" mode took place during the summer 1992 in the North Atlantic, and obtained\nexcellent results. This mode of operation yields a large quantity of data to determine air-sea fluxes of CO2\nat low cost.\nATOC Program\nAn ocean acoustic observatory was established at Ascension Island for long-term monitoring of the North\nand South Atlantic as a strategic node in the ATOC Atlantic network and for short-term basin- and global-scale\npropagation experiments. The communications and data-recording capabilities of the observatory were\nchecked by monitoring signals from acoustic sources deployed in the North Atlantic as part of a Navy-\nsponsored tomography experiment.\nAn analysis was undertaken of the feasibility of locating an acoustic source at Ascension Island as part of\nthe Atlantic ATOC network. A comparison was made between a network based on a source at Ascension\nIsland and a network based on a source off the coast of Cape Town. It was found that a network based on an\nAscension Island source would provide better coverage and would require less sophisticated hardware at\nmany of the proposed receiving sites.\nRainfall Studies\nExperiments were carried out in local ponds to compare acoustical data, rain gauge data, distrometer data,\nan other meteorological data gathered during rainfall events. This analysis will enable better understanding\nof information available on rainfall from acoustical measurements. Instrumentation and software develop-\nment was undertaken in anticipation of the coastal ocean deployment of a multiple-instrument, integrated\nrainfall measurements system.\nPlans FY 93\nClimate Change: Atlantic\nAnalysis of the data collected during the summer of 1992 will be coordinated with the investigators from\nfour academic institutions who took other observations during the ACCP-MB-92-04 cruise and with\nscientists on board the other ships involved in the study. Particular emphasis will be given to the robustness\nof heat flux estimates from single sections, new technologies for estimating deep velocities, and the\ndistribution of deep water masses in the Atlantic. Comparisons of modeled and observed circulation patterns\nwill continue in order to verify model simulations and to provide suggestions for improving model\nparameterizations.\nThe operation of the VOS/XBT Center for the Atlantic will continue. Delayed-mode data collected during\n1990 will be quality controlled to ensure a high-quality data set. In addition, the data will be analyzed to\ndetermine the effectiveness of the Atlantic network for mapping such quantities as gyre positions, intensities,\nand variability. The Center will also participate in a global design study with academic investigators to\ndetermine an efficient network for monitoring upper layer thermal structure. The network will include fixed\nbuoys as well as vos.\n17","Climate Change: Pacific\nAOML is working toward the establishment of an operational drifting buoy array. In 1993, a centralized\nGlobal Drifter Center at Scripps Institution of Oceanography will take over engineering, procurement, and\ndeployment logistics for the buoy array. AOML will cease production of drifting buoys and focus attention\non assembly and quality control of drifting buoy data sets, on oceanographic interpretation of the data, and\non evaluation of the observing system.\nCooperation will continue with Latin American agencies and with the National Ocean Service (NOS) for\nthe collection of XBT and sea level data from the southeast Pacific region. These data will be used with the\ncomprehensive subsurface data base now being assembled for the tropical Pacific. Analysis tasks will include\ncalculating climatologies for various fields, such as SST, selected isotherm depths, layer thicknesses, and\nvertically averaged temperature. In the latter half of 1993 we will focus on comparing the data base to selected\nfields from numerical ocean circulation models, and on analyzing the summer-autumn space-time variability\nin the eastern tropical Pacific.\nThe GEOSAT data set will be reprocessed using the improved orbit and water vapor corrections. These\ndata will then be used to investigate the annual cycle of the North Equatorial Countercurrent in the eastern\nPacific.\nAtmospheric Chemistry North Atlantic Cruise\nSea-air fluxes of several significant chemicals will be investigated during a cruise in the equatorial Atlantic\nand North Atlantic Oceans in FY 93. In addition, 10 to 20 aromatic hydrocarbon oxidation products and\nseveral nitrogen compounds identified during 1991 will be measured to clarify their origins and to estimate\ntheir contribution to boundary layer chemistry.\nIn the summer of 1993, a long line oceanographic section from 5°S to Iceland will be performed to\ndetermine a total carbon inventory of the North Atlantic and to study carbon dynamics. The section will serve\nas a benchmark for future cruises from which the change in ocean carbon content, and thus the amount of\nCO2 uptake from atmosphere, can be determined.\nThe CO2 sampling program will continue aboard Malcolm Baldrige through FY 93, and instruments will\nbe modified SO that less routine maintenance is necessary and the system is more user friendly. Our objective\nis to outfit ships of opportunity similar to the successful Shipboard Environmental Acquisition System (SEAS)\nprogram.\nATOC Program\nBecause of their strategic locations, Ascension Island and Cape Town will be nodes in the Atlantic ATOC\nnetwork. However, propagation models indicate a definite possibility that the acoustic path between\nAscension Island and Cape Town is blocked by St. Helena and by the Bonaparte Seamount, as well as by the\nshallower parts of the Walvis Ridge. A joint experiment will investigate this possibility by recording at\nAscension the signals from acoustic sources deployed by a South African ship while steaming along an\neast-west line from Cape Town. Analysis of these signals will indicate the extent of blockage.\nImprovements to the Ascension Island ocean acoustic observatory will continue. During the next 2 years\nwe will develop an unattended data acquisition system and improved procedures for data transmission.\n18","Atlantic Oceanographic and Meteorological Laboratory\nRainfall Studies\nAdditional pond and oceanic deployments of a multisensor, marine, acoustical rainfall measurement\nsystem are planned. These deployments will provide an initial broad data base for the examination of\nalgorithms for determining rainfall rates in terms of acoustical parameters.\nWEATHER OBSERVATION AND PREDICTION\nAOML's Hurricane Research Division (HRD) is NOAA's primary focus for research on hurricanes.\nResearch teams concentrate on field programs, numerical hurricane modeling, and theoretical studies of\nhurricanes. The NOAA WP-3D research aircraft are used to acquire unique data sets.\nAccomplishments FY 92\nHurricane Modeling Research\nThe goal of this research is to understand and predict the motion, intensity, and structure of hurricanes.\nA general-purpose base model on nested horizontal domains, using an accurate and flexible numerical method\ncalled Spectral Application of Finite Element Representation (SAFER), was developed and is being used by\nthis and other HRD projects. It is anticipated that this will greatly simplify the modeling of moist processes.\nSynoptic-Scale Aspects of Hurricanes\nOmega dropwindsondes (ODWs) dropped from the NOAA WP-3D aircraft are being used to obtain data\nto study the steering currents of mature hurricanes. The ODWs measure temperature, relative humidity,\npressure, and horizontal wind. During data-gathering experiments, the ODW and flight-level data are\ntransmitted from the aircraft to the National Hurricane Center (NHC) and the National Meteorological Center\n(NMC) in real time. We wish to determine whether the ODW observations help improve the official hurricane\ntrack forecasts issued by NHC, what the impact of the ODW data on NMC's dynamical hurricane track model\nis, and what the impact of the ODW data on hurricane track models under development at HRD is.\nSoftware for real-time processing of ODW data was tested on an airborne computer workstation during a\nflight in Tropical Storm Marco in October 1990. The workstation allows the user to display, manipulate, and\nedit the sounding, and encodes mandatory and significant level wind and thermodynamic data, which can\nthen be relayed digitally to NHC and NMC.\nThe SAFER spectral nesting technique developed at HRD was used as the basis for a barotropic hurricane\ntrack prediction model. The spectral technique is used both for the analysis of observations and for the\nsolution of the barotropic forecast equations. This analysis and prediction system (referred to as VICBAR)\ncan produce operational hurricane track forecasts and can be used to study the impact of various types of data\non the prediction of tropical cyclone motion. An assessment of the impact of data from the ODW experiments\non VICBAR hurricane track forecasts was completed. The ODWs produce statistically significant reductions\nin 24-36 h mean forecast errors of 12-16%. This improvement is equivalent to the improvement in\nnormalized (by the climatology and persistence model known as CLIPER) official NHC track forecasts over\nthe past 20-25 years.\n19","Observational Studies of Hurricanes\nTo better understand the electrical properties of hurricanes, analyses of electric field data collected in\nHurricane Gustav (1990) and in two oceanic cloud experiments were completed. The initial detection of\nvertical electric fields in maritime cumulus clouds occurred nearly simultaneously with the initial observa-\ntions of graupel or frozen drops. The strength of the vertical electric field increased with altitude; large vertical\nfields were encountered only during cloud penetrations made at temperatures below 0°C. Clouds that failed\nto reach the melting level did not exhibit detectable vertical electric fields. Hurricane Gustav contained\nmoderate vertical electric fields at 3 km on its north and west sides. Only negative vertical electric fields\nwere observed.\nAnalysis of data from a joint NOAA/Navy air-sea interaction experiment conducted in the Gulf of Mexico\nfrom NOAA hurricane research aircraft before, during, and after the passage of Hurricane Gilbert (1988) is\nin progress. Air-sea interaction plays a vital role in formation and maintenance of hurricanes. Little change\nin SST was observed over the 29°C water of the western Caribbean during Gilbert's explosive deepening to\na record 885 mb on 13-14 September. However, a dramatic decrease in SST accompanied the storm's traverse\nof the Gulf of Mexico on 15-16 September as it maintained its weakened state and dramatically altered wind\nstructure following passage over the Yucatan Peninsula. A gradual basin-wide decrease in SST from 30°C\nto 28°C preceded the arrival of the storm. A further SST decrease to 25°C abruptly followed in the storm's\nwake over a 100-200 km wide area to the right of the storm, except for an area in the central Gulf dominated\nby the warm anticyclonic eddy. The small SST decreases in the Caribbean Sea and Gulf eddy water are\nattributed to the initial mixed layer depths in excess of 70 m. The large SST decreases across the undisturbed\nGulf are attributed to the initial mixed layer depths of less than 30 m.\nIn cooperation with National Center for Atmospheric Research (NCAR) scientists, the role of hurricane\nrainbands in the modification of hurricane structure and intensity is being studied. The rate and degree of\nrecovery of a hurricane planetary boundary layer (HPBL) that has been modified by rainband-associated\ndowndrafts are being assessed, and the impact of the modified HPBL on the eyewall convection is under\nstudy. A rainband/boundary layer experiment was flown on the southeast side of Hurricane Gilbert on\n12 September 1988. Aircraft and ODW soundings indicate that the boundary layer was disturbed on the outer\nside of the band beneath strong subsidence areas. This modified air was replenished with heat and moisture\nby the time it reached the rainband, but surface fluxes alone could not explain the rapid increase of equivalent\npotential temperature along the low-level air trajectory. Calculations with a mixed layer recovery model\nsuggest that additional heat and moisture were provided by entrainment of outward moving air just above\nthe HPBL, which had the thermodynamic characteristics of the rainband axis.\nAtlantic Tropical Climate Studies\nAninvestigation of Atlantic hurricane cycles and the tropical wind variability associated with intraseasonal\noscillations, part of the Climate and Global Change effort, is nearing completion. Wind observations for\n1980-1989 at 200 mb and at a near-surface level were used.\nThe analysis was extended to include outgoing longwave radiation (OLR) to relate the wind fields to\nconvective activity. Aconsistent relationship was found between the vorticity-divergence structure and OLR.\nThe vorticity anomalies tilt westward with height in the higher latitudes, but are barotropic near the Equator.\nThe divergence tends to be in quadrature with the vorticity, and convergence is to the east of the low-level\ntrough. Negative OLR anomalies and upper-level divergence tend to be in phase with the low-level\nconvergence. Thus, convection tends to be associated with low-level convergence and upper-level\ndivergence.\n20","Atlantic Oceanographic and Meteorological Laboratory\nPlans FY 93\nHurricane Modeling Research\nDevelopment of the two-dimensional vertical-plane model will continue, and a series of tests that will\ninclude moist convection will be run. The success of these tests will critically depend on assumptions\nregarding irreversible processes, such as precipitation and nonlinear viscosity. Adequate parameterizations\nthat can be extended to the three-dimensional model must be found.\nA new version of VICBAR that includes background field and boundary conditions from the current\nAviation model forecast will be run during the 1992 hurricane season. After the 1992 season, the VICBAR\nforecast errors from the 1989, 1990, and 1991 seasons will be analyzed.\nObservational Studies of Hurricanes\nAdditional electric field data will be obtained in hurricanes. Although only the vertical component of the\nelectric field has been measured until now, the component parallel to the wings will also be measured in 1992.\nA second computer workstation for the other WP-3D aircraft will be installed and additional software\nimprovements will be made to allow NHC to regularly receive two-dimensional analyses of the mesoscale\nprecipitation and wind structure of tropical cyclone cores. The WP-3D also will be equipped with a C-band\nscatterometer (C-SCAT) for measuring surface wind speed and direction. Comparisons between C-SCAT\nwinds and winds from the Stepped Frequency Microwave Radiometer (SFMR) will be made. Comparisons\nof flight-level winds adjusted to the surface and C-SCAT winds will also be made. A collaborative project\nwith NESDIS will compare the SFMR and C-SCAT observations with Earth Resources Satellite (ERS-1)\nscatterometer observations and Special Sensor Microwave/Imager (SSM/I) radiometer observations.\nAtlantic Tropical Climate Studies\nA study to investigate the relationship of the Atlantic circulation to hurricane development, hurricane\nintensity, and hurricane track was started. Atlantic tropical winds, heights, SST, and measures of African\nrainfall and ENSO will be used. Previous research has established a relationship between hurricane climatic\nfluctuations, the large-scale Atlantic circulation, and SST distribution. A strong relationship between intense\nAtlantic hurricane activity and African rainfall in both the simultaneous and previous season has recently\nbeen reported in the literature. This study will attempt to isolate the physical mechanisms that are responsible\nfor this relationship.\nMARINE RESEARCH\nAOML studies in marine research concern the effects of the environment on fishery populations, the\ndispersion of wastewater in the ocean environment, and processes occurring in seafloor ridges.\nThe Fisheries Oceanography Coordinated Investigations (FOCI) involve NOAA scientists at PMEL,\nAOML, and NOAA's National Marine Fisheries Service (NMFS) Alaska Fisheries Center (AFC), as well as\nacademic scientists. The program seeks to gain understanding of the controls on recruitment variability of\nwalleye pollock in the Shelikof Strait of the western Gulf of Alaska. The major emphasis over FY 86-92 has\nbeen field study of the spawning event and its physical-biological context. The Shelikof system was selected\n21","because of the importance of the resource, the physically restricted study area, previously documented\nvariability in recruitment, and the existence of ongoing NMFS fisheries catch and hydroacoustic monitoring\nprograms. The specific goal of the AOML component has been to document the temporal change in the\nspatial distribution of both eggs and larvae in relation to physical processes (e.g., advection and dispersion).\nField studies conducted during cruises in FY 86-92 enabled us to examine the fine-scale (meters to tens of\nmeters) distribution of pollock eggs, pollock larvae, and zooplankton prey using a towed submersible camera\nsystem, specialized net sampling systems, and, most recently, high-frequency acoustics.\nThe South Atlantic Bight Recruitment Experiment (SABRE) is a component of the Coastal Fisheries\nEcosystem theme within the NOAA Coastal Ocean Program. SABRE seeks to understand the relationship\nbetween variation in environmental factors and variability in the recruitment of \"estuarine-dependent\" fishes\non interannual and longer time scales. The initial target species is the Atlantic menhaden. The SABRE\nprogram was initiated in FY 92 and will include laboratory, field, and modeling efforts. SABRE collaborators\ninclude both NOAA [NMFS Southeast Fisheries Center (SEFC), Great Lakes Environmental Research\nLaboratory (GLERL), and AOML] and academic investigators. The goals of the AOML component are\ndevelopment of the new technology needed to survey menhaden eggs along the Gulf Stream front, design of\na sampling program employing this technology to be conducted by other SABRE groups, and, when the full\nfield program is under way, assessment of the larval predator and prey fields during cross-shelf transit between\noffshore spawning and estuarine nursery grounds.\nThe Nutrient-Enhanced Coastal Ocean Productivity (NECOP) program is a component of the NOAA\nCoastal Ocean Program designed to (1) determine quantitatively the degree to which coastal primary\nproductivity has been enhanced in areas receiving high terrestrial nutrient inputs, (2) determine the effect on\nwater quality (especially dissolved oxygen demand) of this enhanced productivity, and (3) determine the fate\nof the carbon fixed in coastal areas of enhanced productivity and its effect on living resources within the\ncoastal ocean and on the global marine carbon cycle.\nThe Oceanic Plume Studies program studies the interaction of water mass types and the processes that\noccur at their boundaries. Wastewater plumes are a category of water mass that is released in turbulent flow\ninto the receiving oceanic waters. Understanding the dilution that such plumes undergo is an extremely\nimportant environmental concern, and very limited data are available. Understanding the effects of human-\noriginated discharges in the coastal ocean is key to competent resource management. In this program,\nadvanced technology unique to NOAA is being utilized to obtain information on anthropogenic discharges\nof different types and is a component of NOAA's environmental studies mission area.\nOcean ridge studies evaluate the effects on the global ocean environment of seafloor hot springs as major\nagents of chemical and thermal exchanges between the seafloor and the ocean. The studies are performed at\nrepresentative segments of the Gorda-Juan de Fuca Ridge system in the northeastern Pacific and the\nMid-Atlantic Ridge in the central North Atlantic in support of NOAA's global ocean environmental mission.\nThe studies are collaborative with PMEL, NOAA Undersea Research Program (NURP), and a network of\nleading scientists from other U.S. and foreign government agencies and universities. The external funds\nmultiply NOAA funding 5 to 10 times, and external multidisciplinary capabilities significantly increase\nscientific productivity and scope. These efforts are contributing to the NOAA VENTS program, to NOAA's\nrole as the lead U.S. agency with the Institut Francais de Recherche pour l'Exploitation de la Mer (IFREMER)\nin the U.S.-France Bilateral Agreement, to NOAA's role in the U.S.-Russia Bilateral Agreement, and to\nNOAA program development with the Japan Marine Science and Technology Agency (JAMSTEC).\n22","Atlantic Oceanographic and Meteorological Laboratory\nAccomplishments FY 92\nFOCI\nData were analyzed and a manuscript was prepared describing the vertical distribution of pollock eggs and\nlarvae as a function of local hydrography and developmental stage.\nData were analyzed and a manuscript was prepared describing an anticyclonic mesoscale eddy within the\nShelikof Strait and the implication of such phenomena on pollock recruitment.\nSABRE\nAn integrated optical particle counter/video smart sampler was developed for use in egg survey cruises\nalong the Gulf Stream front. AOML scientists participated in a test cruise of egg sampling technology aboard\nthe R/V Cape Hatteras in December 1992.\nHardware development of a modular, six-frequency, searchlight sonar system to assess fish larvae prey\nand predators was completed.\nNECOP\nA series of cruises in the NECOP study area along the western Louisiana shelf was conducted during the\nsummer using three University-National Oceanographic Laboratory System (UNOLS) research vessels\n(Gyre, Pelican, and Longhorn) and the NOAA ship Chapman. Researchers aboard these vessels conducted\nexperiments to determine the effects of anthropogenic input on the Mississippi-Atchafalaya River outflow\narea. Researchers also determined the extent of hypoxia on the Louisiana shelf. All samples collected during\nthe four NECOP cruises completed during FY 91-92 were analyzed and entered into the NECOP data base.\nOcean Plume Studies\nA year-long data set on anthropogenically generated plumes in the coastal ocean was obtained. Included\nin this data set are current meter data gathered at four locations in the coastal ocean off southeast Florida;\nocean currents created during the passage of Hurricane Andrew in August 1992 were also recorded. Plume\ndilution, transport, and behavior have now been determined in a variety of ambient ocean current and density\nconditions. Extensive data sets of currents, density, dilution, nutrients, chemical constituents, and biological\nconstituents were gathered.\nVENTS\nGorda-Juan de Fuca Ridges and East Pacific Rise\nMultidisciplinary data sets were synthesized for publication on the distribution, characteristics, and setting\nof known seafloor hot springs on the Gorda Ridge within the U.S. Exclusive Economic Zone off California\nand Oregon.\n23","A comparative study of seafloor hot springs on the southern Juan de Fuca Ridge and the northern Gorda\nRidge was conducted to determine how differences in volcanism and tectonics control differences in the\ndistribution of these hot springs and their effects on the surrounding ocean.\nThe second stage of development of a prototype sonar system to image hydrothermal plumes was initiated\nby adding the capability to measure fluid flow rates in such plumes (by Doppler phase shift) in collaboration\nwith the Naval Research Laboratory (NRL) and with support from NURP and NRL. The information from\nthese images is being applied to determine the dynamics of dispersal of heat and chemicals into the ocean\nenvironment by the plumes and to guide chemical sampling of plumes.\nMid-Atlantic Ridge\nGiant methane plumes were discovered emanating from inorganic source areas of the deep seafloor on the\nMid-Atlantic Ridge on an IFREMER-NOAA dive series with the French Deep Submergence Vehicle Nautile\nas part of the French American Ridge Atlantic (FARA) program.\nThe first pure gold grains found on an ocean ridge were identified from samples collected from the\nTrans-Atlantic Geotraverse (TAG) hydrothermal site at 26°N on the Mid-Atlantic Ridge on a collaborative\nRussian Academy of Sciences-NOAA dive series. A joint publication was prepared.\nPlans FY 93\nFOCI\nDevelop software to derive real-time estimation of size-frequency histograms from the multiple-\nfrequency acoustic backscatter data.\nComplete and submit a manuscript describing the vertical distribution of zooplankton in the Shelikof\nStrait as a function of local hydrography and developmental stage.\nAnalyze in-situ camera and multiple opening-closing net environmental sampling system\n(MOCNESS) data relative to the working hypothesis that processes associated with the behavior of\nthe Alaskan Coastal Current significantly alter recruitment of locally spawned pollock larvae.\nSABRE\nDevelop software to display in real time histograms of size frequency from multifrequency acoustic\ndata. Develop software for digital image acquisition, processing, and storage of data generated by\negg survey system.\nParticipate in January cruise aboard NOAA ship Albatross IV to test onboard version of egg sampling\nsystem and conduct test survey.\nNECOP\nConduct a series of cruises in the NECOP study area in winter, spring, and summer using chartered\nUNOLS research vessels. Researchers will continue to measure the anthropogenic input introduced\nto the Mississippi-Atchafalaya River outflow area, continue monitoring the seasonal development\n24","Atlantic Oceanographic and Meteorological Laboratory\nand dynamics of hypoxia on the western Louisiana shelf, and map zooplankton distributions about\nthe Mississippi plume to validate the statistical predictions made from prior data.\nOcean Plume Studies\nAnalyze the extensive data set gathered in the preceding 12 months. Additional current measure-\nments will be made at some of the present sites for possibly an additional year. A new program for\nadditional nutrient measurements is in planning.\nVENTS/FARA\nGorda-Juan de Fuca Ridges\nDetermine relations between volcanic features and the distribution and characteristics of hot spring\nactivity along the whole Gorda Ridge within the U.S. Exclusive Economic Zone off California and\nOregon.\nCarry out collaborative NOAA-NRL-Applied Physics Laboratory (University of Washington) dive\nseries with a U.S. Navy submersible to test the plume imaging sonar system and to apply it to VENTS\nprogram interests in the area at the southern Juan de Fuca Ridge designated by the National Science\nFoundation (NSF) Ridge Inter-Disciplinary Global Experiments (RIDGE) program for the first deep\nseafloor long-term observatory.\nDetermine the feasibility of using magnetic methods to remotely sense magmatic intrusions associ-\nated with seismic activity at the southern Juan de Fuca Ridge.\nMid-Atlantic Ridge and Western Pacific (FARA)\nContinue FARA program investigations of the impact of hydrothermal venting from the Mid-Atlantic\nRidge on the ocean by preparing for joint publication of 1992 findings on giant methane plumes and\ncarrying out collaborative dive series with the submersible Alvin with combined NOAA-NSF-IFREMER\nsupport.\nConduct collaborative JAMSTEC-NOAA dive series at seafloor hot springs in the Mariana Basin\n(western Pacific) with the Shinkai 6500 submersible as a basis for joint comparison of effects of\nPacific and Atlantic hydrothermal activity on the global ocean environment.\n25","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nPACIFIC MARINE ENVIRONMENTAL LABORATORY\nSeattle, Washington\n(206) 526-6810\nEddie N. Bernard, Director\nThe Pacific Marine Environmental Laboratory (PMEL) carries out interdisciplinary scientific investiga-\ntions in oceanography, marine meteorology, and related subjects. Current PMEL programs focus on climate,\ncoastal and arctic observation, and prediction and research into the ocean environment. Studies are conducted\nto improve our understanding of the complex physical and geochemical processes operating in the world\noceans, to define the forcing functions and the processes driving ocean circulation and the global climate\nsystem, and to improve environmental forecasting capabilities and other supporting services for marine\ncommerce and fisheries.\nPMEL complements its research efforts through two ERL cooperative institutes: the Joint Institute for\nStudy of the Atmosphere and Ocean (JISAO), with the University of Washington; and the Joint Institute for\nMarine and Atmospheric Research (JIMAR), with the University of Hawaii. PMEL also complements its\nresearch through NOAA's National Marine Fisheries Service (NMFS) and the Cooperative Institute for\nMarine Resources Studies (CIMRS), a joint organization with Oregon State University.\nCLIMATE RESEARCH\nThe NOAA Ocean Climate Program was developed following passage of the National Climate Program\nAct in 1978 in response to increased public awareness of the effects of short- and long-term climatic changes\nand a concern about the potential effects of technology and population growth on world climate. More\nrecently, NOAA and other federal agencies initiated the Climate and Global Change Program to study the\nmechanisms of climate change and to develop prediction models. These two major NOAA programs form\nthe backbone of much of the research conducted at PMEL.\nUnderstanding and forecasting climatic change requires an understanding of the processes of heat,\nmoisture, momentum, and gas exchange between the ocean and atmosphere as well as the large-scale\n27","transports of heat within the atmosphere and ocean. PMEL's climate change research program conducts\nstudies of local and basin-wide ocean dynamics and the coupling of the ocean and atmosphere circulations.\nA specific goal of this research is to determine the physical mechanisms that generate anomalies in sea-surface\ntemperature (SST) distributions in the tropical ocean. A crucial step is to develop and validate ocean\ncirculation models that are capable of simulating the evolution of globally important events such as the El\nNiño-Southern Oscillation (ENSO).\nHeat transport by major western boundary currents (the Gulf Stream and the Kuroshio in the northern\nhemisphere) is postulated to have an important effect on world climate. Western boundary current studies at\nPMEL continue to focus on the Florida Current as part of the Atlantic Climate Change Program. As an\nextension of a program monitoring the evolution of the invasion of chlorofluorocarbons (CFCs) into the\nPacific Ocean, in the next 2 years three World Ocean Circulation Experiment (WOCE) hydrographic and\ntracer sections will be done. These sections will be analyzed in conjunction with data from the complete\nWOCE one-time hydrographic survey of the Pacific.\nOcean chemistry is another aspect of climate change investigations. The addition of anthropogenic\nchemical contaminants to the atmosphere and the potential climatic consequences of these additions has\ncreated a need for improved understanding of the ocean's absorption, transport, and emission of important\ntrace gases. PMEL research in these areas focuses on the carbon cycle in the ocean-atmosphere system and\nthe air-sea exchange of other radiatively important trace gases. These studies involve integrated chemical\nand physical measurements at the ocean-atmosphere interface.\nAccomplishments FY 92\nTOGA TAO Observing Array in Tropical Pacific\nThe Tropical Atmosphere Ocean (TAO) array of Autonomous Temperature Line Acquisition System\n(ATLAS) thermistor chain moorings and PROTEUS (Profile Telemetry of Upper ocean currents) current\nmeter moorings has grown from 28 moorings in October 1991 to 49 moorings that will be in place at the end\nof September 1992. This total includes the deployment of four ATLAS moorings in spring 1992 along the\nEquator in the western Pacific in support of the Tropical Ocean Global Atmosphere Coupled Ocean-\nAtmosphere Response Experiment (TOGA COARE). In the eastern Pacific, 11 new sites from 125°W to\n95°W will be occupied by October 1992. This reflects the completion of the 125°W and 110°W TAO lines,\nas well as new moorings along 95°W. Measurements of rainfall, incoming shortwave radiation, and real-time\nsalinity were added to the array in FY 92. Cooperation from the international community continues with\nsupport from France, Japan, Taiwan, and Korea. The deployment of the entire array is on schedule and is\nplanned to be completed by December 1993.\nStudies were completed in FY 92 on the wind sampling strategies for TAO, showing that almost daily\nobservations are required to resolve monthly wind speed to within 1 m particularly in the western Pacific\nOcean and near the intertropical convergence zone (ITCZ). A detailed examination of the regional response\nto western Pacific westerly wind burst forcing was completed. Additional western Pacific regional studies\non the dynamics of cooling events in the western Pacific, examining the relation between SST changes and\nwind events, and an examination of the role salinity plays in the surface layer mass balance of the western\nequatorial Pacific warm pool have begun. Shipboard and mooring time series data were used to examine\ninterannual variations in currents and hydrography in the central and western Pacific. Data from the moorings\nwere also used to examine the diurnal cycle of temperature variability and its relation to upper ocean mixing\nprocesses in the eastern and western equatorial Pacific. Two empirical modeling studies of equatorial Kelvin\nwave-mean flow interactions in the eastern equatorial Pacific were completed.\n28","Pacific Marine Environmental Laboratory\nATLAS moorings were maintained in the eastern tropical Pacific on joint Equatorial Pacific Ocean Climate\nStudies/Joint Global Ocean Flux Study/carbon dioxide (EPOCS/JGOFS/CO2) cruises. Studies were com-\npleted on the variability (seasonal and annual) of the near-equatorial meridional pressure gradient.\nThe long time series of equatorial current, wind, and temperature data at 0°, 110°W is now in its twelfth\nyear. This observational record is the longest continuous moored time series in the deep ocean. Highlights\nin FY 92 include the publication of a mean seasonal climatology for 0°, 110°W, a comparison of this\nclimatology with others from the same location, and an examination of the dynamics of the mean seasonal\ncycle in the region between 110°W and 140°W. An analysis is under way of interannual anomalies in upper\nocean currents and temperatures from 1980 to 1991, and the relationship of these anomalies to local and\nremote wind forcing. The evolution of the ENSO 1991-92 event was monitored as the eastern Pacific showed\nwarming of 2-3°C above seasonal means.\nPrototype TAO display software was developed to provide interactive, point-and-click access to the most\nrecent 6 months of real-time data from the TAO array in the tropical Pacific. Displays include plots of the\nbuoy data, animations that show data fields measured by the buoy, and data fields generated by the\nNOAA/National Meteorological Center/Climate Analysis Center (NMC/CAC) real-time operational analysis\nmodel. The TAO display software and the real-time TAO data sets from the entire array are available on\nPMEL's anonymous File Transfer Protocol (FTP) Internet account. Several oceanographic and meteorologi-\ncal institutions are using this software or the TAO data. These remote users receive daily updates of the data\nfiles via Internet.\nWestern Boundary Currents\nEstimates of transport variations in the Florida Current continue to be made from cross-stream voltages\nusing an abandoned telephone cable between Key West, Florida, and Havana, Cuba, and an in-service\ntelephone cable between West Palm Beach, Florida, and Eight Mile Rock, Grand Bahama Island. Transport\nestimates in the Florida Straits during 1991 obtained by velocity profiling devices and current meter moorings\nindicate that the cross-stream voltages south of Key West are not seriously contaminated by meanders. The\ncross-stream voltages from the in-service cable contain offsets that we have not yet been able to monitor and\nremove. Since the mooring data show large downstream changes in transport between Key West and West\nPalm Beach, it is necessary to restore the capability to accurately measure transport near West Palm Beach.\nPlans have therefore been submitted for deploying a new cable north of West Palm Beach to replace the\nabandoned cable between Jupiter Inlet, Florida, and Settlement Point that was lost in 1990. In the meantime,\nan effort is being made to improve the accuracy of the voltages from the in-service cable. These transport\nmeasurements are part of NOAA's effort to monitor changes in the northward transport of ocean heat as part\nof the Atlantic Climate Change Program.\nModeling of Tropical Oceans\nModel studies of the seasonal and interannual variability of the tropical Pacific continue, with emphasis\non understanding the mechanisms of SST and upper ocean current variation. As needed for model validation\nor verification, data analysis studies are also carried out. During FY 92, data studies on the space/time\ncharacteristics of westerly wind variability based on the Special Sensor Microwave/Imager (SSM/I) satellite\nanalysis were completed and a technical memorandum was prepared; this work will be submitted for\npublication during FY 93. Model studies of ENSO-to-ENSO variability were carried out using the Florida\nState University pseudostress fields, and an ocean composite ENSO was evaluated for the 1963-1990 period.\nStudies on the relative importance of zonal and meridional wind stress variation in the seasonal cycle of SST\n29","were completed. Studies on the importance of tropical instability waves in the seasonal cycle of upper ocean\ncurrents and SST are nearing completion. The UNIX version of our interactive gridded data set analysis\npackage, FERRET, was released to a number of laboratories and university research groups and is available\nvia an anonymous Internet FTP account to all interested parties. This work supports various EPOCS, TOGA,\nand Climate and Global Change objectives.\nMarine and Atmospheric Chemistry for Climate Change\nPMEL conducts several important marine chemistry programs under the Climate and Global Change\nProgram. Several projects examine ways in which the ocean affects the atmospheric concentration of\nradiatively important trace gases and aerosols by focusing on the biogeochemical cycles of carbon, sulfur,\nnitrogen, and oxygen. Another program measures the changing concentration of anthropogenic CFCs in the\nocean to elucidate pathways and rates of thermocline ventilation and circulation and sequestration of\ngreenhouse gases.\nBiogeochemical cycles\nDuring 1992, PMEL scientists participated in three international cruises as part of the International\nGeosphere/Biosphere Program's JGOFS and International Global Atmospheric Chemistry (IGAC) program.\nSeveral ships and many institutions joined in the equatorial Pacific to study the biogeochemical cycles of\ncarbon and sulfur in the surface ocean waters and the flux of these elements to both the deep ocean and\natmosphere. One striking result of the equatorial work was discovery of evidence for wave-like features in\nthe salinity, temperature, total CO2, and nitrate data. The wavelengths of the features are approximately 8°\nof longitude. These features are the first evidence that equatorial longwaves play an important role in\ncontrolling short-term variations of near-surface chemical properties along the Equator.\nCFC Tracer Program\nThe PMEL CFC Tracer group is continuing a series of long sections designed to document the penetration\nof CFCs into the ocean. These sections have been upgraded in sampling density and coverage of tracers SO\nthat they contribute to the WOCE one-time hydrographic survey of the Pacific. In FY 92, PMEL organized\nand carried out a section in the western Pacific between Kamchatka (60°N) and New Caledonia (20°S).\nDuring the year, measurements of CFCs were made on two WOCE sections in the Southern Ocean. PMEL\nhas established a WOCE CFC gas standards group that distributes the standards to the 12 countries\nparticipating in WOCE.\nPlans FY 93\nTOGA TAO Observing Array in the Tropical Pacific\nContinue implementation of the TOGA TAO array.\nParticipate in the intensive observing period of TOGA COARE (November 1992-February 1993).\n30","Pacific Marine Environmental Laboratory\nBegin implementation of an equatorial Pacific, basin-scale, moored rain-gauge array.\nDescribe the 1991-1992 ENSO event from TAO data.\nContinue joint analyses of Tropical Instability Wave Experiment (TIWE) and JGOFS data with\nNational Science Foundation (NSF) investigators.\nContinue investigations of the mean seasonal cycle and interannual variability from long moored\ntime series measurements in the equatorial Pacific.\nContinue development of the TAO workstation.\nWestern Boundary Currents\nContinue Key West and West Palm Beach voltage measurements.\nUpgrade the West Palm Beach voltage measurements.\nRefine plans for deploying a new cable across the Florida Straits.\nCompare Florida Current transport variations with surface winds and temperature.\nModeling of Tropical Oceans\nComplete the first set of seasonal cycle studies.\nPrepare manuscript on hindcasts of the 1986-88 ENSO event.\nInitiate new experiments to diagnose the 1992-92 ENSO.\nBegin a variety of ocean observing system evaluation studies.\nMarine and Atmospheric Chemistry for Climate Change\nComplete analysis of Equatorial Pacific JGOFS cruise data.\nParticipate in an atmospheric chemistry cruise from Antarctica to the Gulf of Alaska to measure the\nradiatively important trace gases in the surface ocean and overlying atmosphere and aerosols in the\nmarine boundary layer.\nBegin chemical analyses of aerosols from the new NOAA aerosol station network.\nProvide CO2 and CFC measurements on meridional section in the North Atlantic [joint PMEL/\nAtlantic Oceanographic and Meteorological Laboratory (AOML) cruise].\nConduct a joint NOAA/JGOFS Equatorial Pacific Study to determine the sources and sinks for CO2\nduring the fall season.\nPrepare a report on the distribution of CO2 and hydrographic parameters in the equatorial Pacific\nduring the spring of 1992.\n31","COASTAL AND ARCTIC RESEARCH\nAccomplishments FY 92\nFisheries Oceanography Coordinated Investigations\nBy determining the effect that coupled physical-biological interactions have on annual changes in\nrecruitment, Fisheries Oceanography Coordinated Investigations (FOCI) can improve the effective manage-\nment of the vast, commercially valuable stocks of walleye pollock (Theragra chalcogramma) in Alaskan\nwaters. The goal of FOCI is to understand the processes that lead to variations in recruitment. Research has\nbeen conducted in support of the paradigm that such fluctuations exist as a result of events during early life\nhistory. Our focus has been to elucidate physical and biological phenomena and to understand how complex\ninteractions between these two affect rates of mortality. Our understanding of processes affecting recruitment\nhas advanced to the degree that FOCI has provided U.S. fishery management with information for establishing\npollock fishing quotas in the Gulf of Alaska. The information supplied was an estimate of pollock biomass\ndetermined from sources independent of the commercial fishery.\nUntil FY 92, most research was conducted in the Shelikof Strait region of the Gulf of Alaska. This stock\nof pollock is commercially important and has a tractable early life history. It was critical that the first regional\nstudy be one that would foster scientific cooperation among the various disciplines. Since its inception in\n1985, FOCI has developed physical and biological methods and assembled a team of scientists capable of\nand interested in conducting interdisciplinary research. We recently augmented the domain of research by\nadding a Bering Sea component to FOCI under the auspices of NOAA's Coastal Ocean Program. The Bering\nSea is the primary location of the pollock fishery. Research is focused on identifying the different\naggregations of pollock and their relation to dominant circulation features of the deep basin.\nShelikof Strait, Gulf of Alaska\nFOCI provided U.S. fishery management with information critical for establishing pollock fishing quotas\nfor the Gulf of Alaska.\nA Semispectral Primitive Equation Model (SPEM) of currents in the region of Shelikof Strait is operational.\nIt generates mesoscale features with radial velocities and salinity signatures similar to those observed in\nnature. Data from moorings recovered from Shelikof Strait are being used to verify the model.\nAnalysis of sea level and horizontal variability has shown that high sea-level events indicate strong currents\nthat could have serious repercussions on larval transport. Sea-level differences correlate with recruitment\nfor the past 10 years.\nThirteen moorings deployed in FY 91 were recovered this year during three spring cruises to Shelikof\nStrait.\nAnalyses were completed of water property, Lagrangian drifter, and larval distribution data collected\nduring spring 1990. These analyses reveal a strong clockwise rotating eddy that existed over the sea valley\nfor several weeks. Estimates of larval mortality within this feature support physical analyses that suggest\nthere was little exchange between the eddy and adjacent water.\nFOCI conducted an experiment to measure larval mortality in a marked patch of water. The outcome\nstrongly suggests ways to improve experiment design.\nA network of meteorological stations was deployed in support of modeling studies of primary and\nsecondary productivity.\n32","Pacific Marine Environmental Laboratory\nBering Sea\nThe first full year of Bering Sea FOCI was completed as a joint effort of scientists from five universities,\nPMEL, the Alaska Fisheries Science Center, and the Russian Research Institute of Marine Fisheries and\nOceanography (VNIRO) and Pacific Research Institute of Fisheries and Oceanography (TINRO) from\nRussia. The goal is to provide scientific information to reduce uncertainty in decisions of resource\nmanagement concerning the abundance of walleye pollock. The two primary questions are whether there\nare separate stocks of pollock throughout the Bering Sea basin, which bears on the issue of overfishing in\ninternational waters (Doughnut. Hole), and what is the recruitment to the largest pollock population in the\neastern Bering Sea near Bogoslof Island. To address these issues, studies are being conducted of the physical\nand biological environments of the Bering Sea.\nThe goal of stock separation through microbiological techniques is to develop molecular techniques that\nwill allow unambiguous discrimination of eggs, larvae, fry, and adults of the various pollock populations.\nInitial studies have focused on the D-loop region, the cytochrome b gene, phenylalanine tRNA, proline tRNA,\nthreonine tRNA, and 12S rRNA regions of mitochondrial DNA (mtDNA). We have successfully amplified,\ncloned, and sequenced the cytochrome b gene and the D-loop region of the mitochondrial DNA (mtDNA) of\nseveral representatives of Russian and American pollock populations from the southwest Bering Sea shelf,\neast Kamchatka Peninsula, northwest Pacific, southeast Bering Sea shelf, southeast Aleutian Basin (Bogos-\nlof), and Central Basin (Doughnut Hole).\nThe first major effort in 20 years to measure Bering Sea circulation was conducted in August 1991, when\na joint U.S.-Russian cruise made extensive observations aboard the NOAA ship Miller Freeman. Four major\ndata sets were obtained from 112 conductivity, depth, temperature (CTD) stations in both Russian and U.S.\nwaters; five current moorings in Amchitka Pass, Near Strait, and on the northern continental slope; 25\nsatellite-tracked drifting buoys; and the shipboard acoustic Doppler current profiler (ADCP) operating on\ndedicated transects. A major finding resulting from these observations is that the Alaskan Stream was not\nflowing into the Bering Sea through Near Strait. Five drifters moved offshore rather than through Near Strait.\nThis anomaly started in fall 1990 and persisted through at least 1991. This finding has been accepted for\npublication, and other results from the cruise will be submitted for publication. A second Bering Sea cruise\nwas conducted in September 1992 aboard the Miller Freeman. Five current moorings deployed in August\n1991 were recovered, along with the PROTEUS mooring deployed in April 1992. Ten satellite-tracked\ndrifters were deployed and CTD casts were taken in the vicinity of Amchitka Pass, Near Strait, and in the\nAlaskan Stream.\nA limited-area, primitive equation, three-layer, hydrodynamic model, with realistic coastlines and\nbathymetry and 1/8° resolution, based on the Naval Research Laboratory (NRL) model, was used to\ninvestigate the circulation of the Bering Sea Basin and the adjacent North Pacific Ocean. The details of the\nmodel circulation are generally consistent with available hydrographic and buoy drift observations. The\nnumerical study demonstrates that flow instabilities contribute to substantial interannual variability in the\ncirculation of the Bering Sea and adjacent northwest Pacific Ocean.\nSurface stresses over the Bering Sea for 1946-1990 were estimated from sea-level pressure analyses,\nempirical relationships between the geostrophic wind and the surface wind, and a bulk aerodynamic formula.\nResults are similar to those found in previous studies of the wind forcing of the midlatitude oceans, and of\nthe lower-tropospheric variability over the North Pacific. Sverdrup transports estimated for the Bering Sea\nbasin account for roughly one-half of the observed transport within the western boundary current along the\nKamchatka peninsula and exhibit substantial interannual to interdecadal variability.\nTime series reconstruction was completed to allow analysis of the continuous time series of sea surface\nheight measurements in the Bering Sea, spanning April 1985 through November 1988. Spectral analysis is\nin progress to identify the dominant frequencies contained in each of these modes. Preliminary results show\n33","that mode 1 and mode 2 are annual and semiannual signals that contribute a significant portion of the total\nvariability in the Bering Sea sea surface height signal.\nIn the vicinity of Bogoslof Island, an apparently stable spawning population of walleye pollock, of\nsignificant commercial value, exists. Hence, this region forms a natural laboratory for addressing questions\nregarding survival and transport of larval pollock. During the past year, analysis of previously collected data\nwas undertaken. Based on this analysis, new information is available regarding the physical oceanography\nof the southeastern Bering Sea. The observations substantiate the existence of the Bering Slope Current, a\nmoderate, persistent flow toward the northwest along the upper continental slope. These results are important\nto understanding the environment in which eggs and larvae exist, the behavior of larval transport, and\nmodeling efforts in support of FOCI goals in the eastern Bering Sea.\nThe Bering Sea FOCI cruise conducted in April 1992 examined pollock larval distributions and transport\nin relation to oceanographic conditions. The objective of this study is to examine the fate of eggs and larvae\nspawned by the Bogoslof population. Larval distribution was mapped to determine the predictability of larval\noccurrence in space and time for future years. These data will allow determination of horizontal and vertical\ndistribution and abundance by age.\nAn existing (nutrients-phytoplankton-zooplankton model was modified to include more realistic and\ndetailed parameterizations of age structured zooplankton and larval pollock population dynamics, and more\nrealistic and detailed parameterizations of larval pollock feeding. The model will be reformulated and applied\nto each of several oceanographic domains in the Bering Sea to investigate the production dynamics of the\npelagic ecosystem.\nArctic Research\nChukchi Sea studies\nThe first stage of the joint Russian/American research program in the western Arctic, where the Pacific\npours large amounts of low-salinity, high-nutrient water onto the Arctic shelves, was completed. Thirteen\nmoorings were recovered from the Chukchi Sea in the fall of 1991, and hydrographic stations on both sides\nof the Convention Line were sampled with a large suite of measurements. The data set has been fully\ncalibrated and processed. Of particular interest is the early finding that the vertical and horizontal structure\nof the velocity field in Bering Strait appears relatively simple. Therefore transport through the strait can\nprobably be monitored through relatively inexpensive and straightforward means in the future. A small\nnumber of instruments deployed during 1991-92 are designed to take advantage of this and maintain\ncontinuity in the transport time series begun under this program in 1990.\nGreenland Sea/Atlantic Climate Change Program\nMonitoring of the fresh water flux from the Arctic into the North Atlantic was begun in 1991 under the\nClimate and Global Change Program. The work is being performed in cooperation with the Polar Research\nInstitute in Norway and the University of Hamburg and the Alfred Wegener Institute in Germany.\n34","Pacific Marine Environmental Laboratory\nSea ice-troposphere interaction\nThe LEADS project in March and April 1992 included deployment of four meteorological ice drifting\nstations in a 100-km array located 300 km north of Barrow, Alaska, in the Beaufort Sea. The buoys drifted\nthroughout the spring, measuring ice motion, wind velocity, currents, and air and snow temperature.\nComparison of wind data to ice motion showed much more high frequency variability in the ice deformation\nmotion than in the wind deformation. Primary coupling was between the wind and ice shear at 5-day periods,\nthe period of storm occurrence. Winds over the LEADS area varied from 15 m S to 9 m over a distance\nof 200 km as measured by NOAA P-3 research aircraft during a major storm. The response of the ice field\nappeared to be similar to a transform fault, with offsets occurring roughly every 5 km. This pattern\nobservation is new information that contributes to the development of improved regional sea-ice models.\nTsunami Project\nThe PMEL Tsunami Project, as part of the Coastal Hazards element of NOAA's Coastal Ocean Program,\nseeks to mitigate tsunami hazards to Hawaii, California, Oregon, Washington, and Alaska. To meet this\nobjective, the Tsunami Project established the Pacific Tsunami Observation Program (PacTOP) to obtain\nhigh-quality tsunami measurements in the deep ocean and coastal regions-data that are essential to an\nimproved understanding of tsunami generation, propagation, and inundation dynamics.\nField experiments\nThree oceanographic cruises were successfully completed to recover and redeploy six bottom pressure\nrecorders (BPRs) of the PacTOP network. All instrumentation was recovered, and an additional offshore\nstation was established near the Hawaiian Islands, in collaboration with the University of Hawaii.\nDevelopment of methodology for BPR analysis\nA report was completed on the analysis of a BPR data set using a methodology that utilizes both analytic\ntheory and an optimization approach to wave ray construction. The results suggest that the deep ocean BPR\ndata being collected by the field program, when properly analyzed, can be extremely useful in the study of\ntsunami generation and propagation dynamics.\nMarianas Trench tsunami data\nTide gauge data for the Marianas Trench tsunami were acquired. A new, more accurate technique was\ndeveloped to digitize such records, and it was successfully applied to these records. The resulting data were\nprocessed to remove low frequency energy and extract the tsunami signal, and data were exchanged with\nJapanese scientists.\n35","Hilo Harbor inundation\nThe planned inundation modeling of Hilo Harbor has been completed, using SWAN, a finite-difference\ncode developed at JIMAR. A preliminary map was prepared, to be compared with similar simulations to be\nmade using a finite-element version of a state-of-the-art inundation model developed by the Japanese.\nLow frequency sea-level variations\nA report has been completed on low-frequency sea-level variations in the Pacific Northwest. This study\nemployed recently developed spectral methods (prolate data windowing and jackknife averaging) to show\nthat subtidal water level variations in the Strait of Juan de Fuca and Puget Sound region can be explained by\nthe local response to atmospheric pressure and propagation of barotropic and baroclinic signals from the\nnearby coastal region.\nPlans FY 93\nShelikof Strait, Gulf of Alaska\nExamine Eulerian water property data for a census of eddies and their properties (e.g., rotation, size,\nsalinity) in the Shelikof Strait.\nExamine long-term time series of physical and biological factors to elucidate interrelationships that\nprovide insight to forecasting year-class strength of walleye pollock.\nAnalyze results from volume transport data (13 moorings) that will supply upstream boundary\nconditions for SPEM.\nContinue integration of SPEM and IBM techniques; continue use of Synthetic Aperture Radar (SAR)\nto locate eddies.\nBering Sea\nConduct an echo integration-midwater trawl survey of the Bering Sea during the winter of 1993 to\nassess the distribution and abundance of walleye pollock. This cooperative survey effort will involve\nthe United States, Russia, and Japan, and is planned to span the entire Bering Sea.\nContinue work on molecular and chemical techniques for stock separation, with emphasis on\nrecruitment and trophic level interactions of eastern Bering Sea pollock populations. A cruise is\nscheduled for 26 March-1 April 1993 to redeploy the PEGGY platform and collect samples to\ndetermine the vertical distribution of pollock eggs and larvae and plankton species. A second leg,\nscheduled for 14-27 April 1993, will include zooplankton and larvae feeding experiments, a larval\nmortality experiment, and studies of local transport and water properties.\n36","Pacific Marine Environmental Laboratory\nChukchi Sea Studies\nAnalyze the rich data set resulting from the recent joint Russian/American studies in the Chukchi\nSea, supplemented by data from ongoing monitoring of the system.\nRecover the first year's arrays in the northern part of the East Greenland Current, and install new\nmoorings for another year of measurements.\nSea Ice-Troposphere Interaction\nInvestigate the relation of air-ice momentum coupling to the stability of the lower atmosphere by\nmaking use of the recently available Soviet ice station data.\nTsunami Project\nMaintain the PacTOP network by recovery and redeployment of deep-ocean BPRs.\nContinue development of methodology for BPR tsunami analyses.\nComplete inundation modeling of Hilo Harbor, Hawaii, using Japanese model.\nExtend the low-frequency sea-level variation techniques to assess the potential impact of background\nsea level variations on tsunami inundation.\nInvestigate the relationship of coastal to offshore sea level variations by comparing coastal tide gauge\nrecords with offshore BPR data.\nOCEAN ENVIRONMENT RESEARCH\nThe VENTS Program, in its ninth year of research, focuses on determining the oceanic impacts and\nconsequences of submarine hydrothermal venting. The program directs most of its efforts toward achieving\nan understanding of the chemical and thermal effects of venting along the northeast Pacific seafloor spreading\ncenters on the North Pacific Ocean. The understanding obtained from this relatively isolated system will\neventually be extended to a prediction of the impact of seafloor hydrothermal systems throughout the global\nocean. The attainment of the overall program goal requires a long-term interdisciplinary approach.\nAccomplishments FY 92\nResearch results obtained during FY 92 continued to support the hypothesis that hydrothermal venting at\nseafloor spreading centers has global significance in terms of the chemical and thermal state of the ocean.\nNOAA VENTS Program scientists, together with their non-NOAA research collaborators, are successfully\ndocumenting these effects as they occur in the ocean over a very wide range of temporal and spatial scales.\nThis year saw the use of a remotely operated vehicle (ROV) at hydrothermal vent sites along the Juan de\nFuca Ridge. The HYSUB 5000 ROV was operated by the Institute of Ocean Sciences (IOS), Sydney, British\nColumbia. NOAA (PMEL VENTS Program), IOS, the Department of Energy and Mines of Canada, and\nNatural Sciences Resources Canada jointly contributed to the expedition. This cruise was an unqualified\n37","success and marked the first time that geological, biological, and chemical samples, which require delicate\nmanipulation and precise positioning, were obtained from the midocean ridge by an ROV. The ROV was\nalso utilized to recover several months of data from an instrumented Ocean Drilling Program drill hole on\nthe northern part of the ridge.\nTwo new state-of-the-art instrument systems were deployed on the ridge during FY 92. These instrument\nsystems are designed to detect and measure crustal motion in two planes. Vertical crustal motion is being\nmeasured by two rumbleometers at the North Cleft site and one in the Axial Volcano caldera. The\nextensometer system, also deployed at the North Cleft site, is measuring horizontal crustal motion.\nVENTS research during FY 92 was concentrated, as in past years, on (1) determining patterns and pathways\nfor the regional transport of hydrothermal emissions as well as source strengths of the emissions and their\nrelationships to the geology and tectonics of spreading centers, and (2) further developing capabilities for\nmonitoring hydrothermal activity at a wide range of temporal and spatial scales.\nTransport and Source Strengths of Hydrothermal Emissions\nTemporal and spatial monitoring of the effects of hydrothermal venting from midocean ridges continued\nin FY 92. Research was concentrated on the Cleft Segment of the Juan de Fuca Ridge in the northeast Pacific\nOcean. Results from this work have revealed significant yearly variation in the intensity of venting. In\naddition, an array of seven miniature temperature recorder moorings established during FY 91 was recovered.\nThese moorings represent the first continuous year-long monitoring of hydrothermal plumes. The array was\nexpanded to 11 moorings and redeployed in FY 92.\nThe effects of heating at the Juan de Fuca Ridge may be seen at least as far as 1000 km to the west according\nto CTD observations. These may be isolated plume eddies that have become detached from their sources.\nChemical traces in the form of helium isotopes (He) originating from the ridge hydrothermal venting can be\ntraced as a continuous signal out to a longitude of at least 180° in the north Pacific. On the basis of the\ncorrelation between He and silica, it is estimated that approximately 10-20% of the dissolved silica anomaly\nin the north Pacific is hydrothermal in origin.\nResearch was expanded to a second site on the East Pacific Rise in FY 92. The rise, at 10°N, is a fast-rate\nspreading center; it will be compared to the Juan de Fuca Ridge, a medium-rate spreading center.\nHydrothermal Monitoring\nThe T-phase event detection system is a long-range acoustic surveillance tool that provides a means to\ncontinuously monitor the Northeast Pacific and virtually the entire Pacific basin using the U.S. Navy's\nIntegrated Underwater Surveillance System (IUSS). T-phases are acoustic signals that are generated by,\namong other things, submarine earthquakes and submarine volcanic eruptions. Detection of clusters of\nT-phases (earthquake swarms) that often accompany volcanic eruptions is expected to give VENTS Program\nscientists the ability to study resultant episodic hydrothermal activity while it is in progress. Initial results\nshow that the volcanic system off the northwest coast of North American is at least two to three orders of\nmagnitude more seismically active than was previously observed on the basis of land-based seismic\nmonitoring networks. The VENTS T-phase project is the first of its kind in the United States, and NOAA\nVENTS is playing a key role in developing civilian scientific applications for the U.S. Navy's hydrophone\nacoustic data.\nAccomplishments during FY 92 include the modification of data collection software and the collection of\nover 100 gigabytes of data. Detection software is operational, and nearly half of the collected data have been\nexamined. Event location methods have also been developed and are being implemented.\n38","Pacific Marine Environmental Laboratory\nPlans FY 93\nReduce, analyze, and interpret physical, chemical, and geological oceanographic data obtained\nduring the FY 92 VENTS Discoverer field season.\nConduct the FY 93 VENTS Discoverer field season, expanding on the success of the FY 92 ROV\nuse.\nAnalyze samples and data from the 9°-11°N East Pacific Rise Study. The data will be used to compare\nchemical processes and source strengths on the Juan de Fuca Ridge and those of the East Pacific\nRise.\nContinue the decadal-scale monitoring of hydrothermal venting variability on the Cleft Segment of\nthe Juan de Fuca Ridge including 3 He-heat-silica relationships using existing and recently developed\ninstrument systems.\nContinue annual and continuous monitoring of hydrothermal plumes at the Cleft Segment in\nconjunction with in situ and remote geophysical monitoring of volcanic activity.\nContinue development of numerical models of physical and chemical processes in the water column\naround hydrothermal vents and spreading ridges.\nContinue development of procedures and software to effectively collect, process, and evaluate\nT-phase signals.\nContinue collaboration with the U.S. Navy in developing civilian use of IUSS hydrophone arrays\nfor scientific purposes.\n39","","Office of the\nDirector\nJoint\nInstitutes\nARL\nSEL\nFSL\nWPL\nAOML\nGLERL\nAL\nNSSL\nCMDL\nPMEL\nGFDL\nGreat Lakes Environmental Research Laboratory\nAnn Arbor, Michigan\n(313) 668-2235\nAlfred M. Beeton, Director\nThe Great Lakes Environmental Research Laboratory (GLERL) conducts integrated, interdisciplinary\nenvironmental research in support of resource management and environmental services in coastal and\nestuarine waters, with special emphasis on the Great Lakes. GLERL's scientific programs are organized into\nCoordinated Research Programs considered critical to the NOAA mission and Great Lakes problems\n(Non-Indigenous Species, Climate Variability and Global Change in Large Lakes, Pollutant Effects, Marine\nHazards and Water Management) and, in addition, the Nutrient-Enhanced Coastal Ocean Productivity\n(NECOP) program, the Great Lakes CoastWatch program, and several independent research projects.\nNON-INDIGENOUS SPECIES\nThe goal of the Non-Indigenous Species Coordinated Research Program is to expand knowledge of the\nbiology and the ecological effects of non-indigenous species in the Great Lakes. One species, the zebra\nmussel (Dreissena polymorpha), recently introduced into the Great Lakes, has the potential to dramatically\nalter trophic relationships of the entire ecosystem. Dreissena is capable of increasing in numbers very rapidly\nand is likely to have a profound effect on the cycling of materials as well as ecological implications to other\nspecies.\n41","Accomplishments FY 92\nEffects of the Zebra Mussel on Lower Food Web of Saginaw Bay\nThe objectives of this project are (1) to identify and understand changes in the abundance, biomass, and\ncomposition of the lower food web of Saginaw Bay that have resulted from the invasion of the zebra mussel;\n(2) to construct a model of carbon flow through the system and determine major changes in pathways; and\n(3) to monitor changes in the abundance and distribution of the zebra mussel in the bay. In FY 92, samples\nwere collected at 26 stations monthly beginning in April. In addition, zooplankton grazing rates were\ndetermined at six of the stations in June. Experiments to determine filtering rates of zebra mussels were\nconducted during each sampling period. Changes in carbon, chlorophyll, and dry weight of suspended\nparticulates were measured over time. Abundance estimates of zebra mussels were obtained from the same\nlocations as in 1991. All conductivity, temperature, and depth (CTD) data from the monitoring cruises were\nprocessed and archived. Ten global positioning system drifters were tested and used on Saginaw Bay. Each\ndrifter internally records its position and temperature from seven thermistors at a user-selected time interval.\nMetabolic Physiology of the Zebra Mussel\nThis program seeks to seasonally determine oxygen consumption and nitrogen excretion of zebra mussels\ncollected from Lake St. Clair, and lipid content and C:N ratios of soft tissue from zebra mussels. In FY 92,\nmussels were collected monthly from April to November in Lake St. Clair and Saginaw Bay. Specimens\nwere analyzed for lipid content, carbon content, nitrogen content, and ash-free dry weight.\nToxicokinetics and Bioaccumulation of Organic Contaminants by the Zebra Mussel\nThis project is assessing the impact of the zebra mussel on the distribution of contaminants in ecosystems\ndominated by these organisms. These selected chemicals, primarily polychlorinated biphenyls (PCBs) and\nthe polycyclic aromatic hydrocarbons (PAHs), will be representative of both their class and the physical and\nchemical characteristics embodied in the chemicals as model compounds. Compounds from other chemical\nclasses will be employed where specific characteristics will be helpful to determine specific processes or\nmechanisms of action. In FY 92, work continued to examine the relationship between temperature and the\naccumulation of organic contaminants from water, measurements of toxicokinetics of the organic contaminant\npentachlorophenol were taken to increase the data base for toxicokinetics in the zebra mussel, and methods\ndevelopment continued to determine the appropriate experimental design to examine the accumulation of\norganic contaminants from ingested particles.\nDirect Observations on the Trophic Ecology of Dreissena Early Life Stages:\nThe Critical Planktonic Period\nThe pelagic phase (eggs and larvae) is a weak link in the life cycle of the zebra mussel with mortalities of\nnearly 100% depending on environmental conditions (narrow window of temperature, food, predation, etc.).\nThis program is (1) observing feeding mechanisms, particle choice, and feeding rates of Dreissena larvae;\n(2) determining nutritional requirements of Dreissena larvae; and (3) determining the vulnerability of\nDreissena eggs and larvae to zooplankton. In FY 92, we successfully maintained adult zebra mussels in the\nlaboratory and forced them to produce viable fertilized eggs that will survive with little mortality to the D-shell\n42","Great Lakes Environmental Research Laboratory\nstage, the stage at which they first start feeding. We grew Dreissena larvae using static and continuous culture\nmethods with different combinations of algae. We have a combination of algae that have allowed growth\nfrom 110 um, a size approaching the post veliger D-stage, to 150 um. The experimental results point to the\nnutritional quality of the algae as the limiting factor. Preliminary experiments that deal with the predation\non Dreissena by various predators were completed.\nLong-Term Changes in the Resuspendable Sediments of Saginaw Bay\nDuring feeding, adult zebra mussels capture suspended particulate matter (SPM) and redeposit it as feces\nand pseudofeces on the bottom. The activity will possibly change the composition and mobility of materials\nin the sediment resuspendable pool in Saginaw Bay, resulting in changes in system residence times of\nparticle-associated constituents. This program is (1) deploying autosequencing sediment traps at two\nlocations in Saginaw Bay for the collection of resuspendable sediments; (2) analyzing these samples optically\nfor gross compositional changes and for nutrients, carbon, and Cs-137 to estimate the resuspension flux of\nthese constituents; and (3) measuring the stable isotope composition of the biota to examine carbon and\nnitrogen pathways and changes caused by the mussel. In FY 92, we recovered the first trap deployment,\nanalyzed ten 7-day-interval mass and carbon fluxes, and collected biota for isotope analysis.\nEffects of the Zebra Mussel on Nutrient Cycling and Lower Food Web Dynamics\nin Saginaw Bay, Lake Huron\nBy altering the phytoplankton and bacterial biomass, both of which compete for phosphorus, and the\nsuspended particulates, zebra mussels may affect nutrient cycles and microbial dynamics in the bay. This\ntask is (1) determining the direct and indirect effects of the zebra mussel on nutrient regeneration and uptake\nby various trophic components in the lower food web; (2) determining the effects of the zebra mussel on\nbacteria standing crop, cell size, and growth rates; (3) determining how the sources, cycling rates, and fate\nof labile dissolved organic matter are affected by the presence of the zebra mussel; (4) collecting and\ndetermining the \"nutritional composition\" of feces and pseudofeces produced by the zebra mussel; and\n(5) comparing field observations of standing stocks and process rates with those predicted from bottle and\nmesocosm experiments. In FY 92, a series of bottle experiments and one large mesocosm experiment were\nconducted to examine the effects of the zebra mussel on nutrient cycling and microbial dynamics in Saginaw\nBay. Although the measurements and data handling are not yet complete, the following observations were\nmade: The zebra mussel often quantitatively removes chlorophyll and other particles from the water, but the\ndegree of particle removal appears to vary seasonally and to depend on the composition of the phytoplankton\nin the water. In zebra mussel infested areas, zebra mussel excretion appears to be an important process that\naffects community nutrient regeneration rates. Regeneration rates for both ammonium and phosphate are\ndirectly increased in the presence of the zebra mussel. The presence of zebra mussels changes the abundance,\nsize, and activity of bacteria in the water. Bacterial-sized particles were removed more rapidly from the water\ncolumn in the presence of zebra mussels than in their absence, but at this time, we do not know whether the\neffect is direct or indirect. Zebra mussels affect the ability of the microbial community to take up and\nregenerate phosphorus, but the magnitude of this effect is dependent on how the zebra mussel responds\nto\nthe existing phytoplankton communities.\n43","Plans FY 93\nHold a planning meeting to discuss and coordinate FY 93 sampling with participants from federal\nand state agencies and academic institutions involved in the program.\nContinue monthly monitoring at the 26 stations.\nContinue sampling mussels at sites in Lake St. Clair and Saginaw Bay and analyze for lipids, carbon\nand nitrogen content, and weight.\nExpand the time slots for drifter experiments to spring, summer, and possibly fall.\nContinue culturing and experimental work with Dreissena larvae feeding to continue our success\nwith obtaining viable fertilized eggs and growing larvae to 150 um.\nPerform experiments using a variety of zooplankton to determine predation rates on larvae before\nand after shell formation.\nDetermine the feeding rate of zebra mussel larvae on various algae including picoplankton.\nExamine the field data on zooplankton and Dreissena abundance to develop a model to predict\ngrazing.\nAnalyze second sediment trap deployment data for mass and carbon fluxes and compare 2 years of\ndata.\nConduct stable isotope analysis of the food webs of Saginaw and Green Bays.\nContinue experiments in Saginaw Bay to verify seasonal trends on nutrient cycling and bacterial\ndynamics, as affected by the zebra mussel, that were observed over the last year and to define the\nmechanisms responsible.\nBegin preliminary analysis of phosphorus excretion rates.\nContinue to design and perform studies to assess the assimilation of organic contaminants from\ningested particles.\nIncorporate studies on the role of environmental and physiological factors of toxicokinetics to\nexamine the effect of these variables on assimilation of ingested contaminants.\nDevelop methodology to study the movement and accumulation of organic contaminants in zebra\nmussels in the field.\nCLIMATEVARIABILITY AND GLOBAL CHANGE IN LARGE LAKES\nThe Great Lakes are an excellent candidate for climate change research due to physical and biologi-\ncal/chemical measurable signals, long-term records, ongoing physical process studies, and the importance of\nresources (e.g., a multibillion dollar sport and commercial fishery, fresh drinking water for a large segment\nof the U.S. population, a multibillion dollar commercial transportation waterway). Large lakes, including\nthe Laurentian Great Lakes, are \"closed systems\" with boundaries on spatial scales and with processes that\nmake them more tractable for study than the oceans. Many of the environmental situations that make some\nof the oceanic systems desirable for study of climate change are also present in the Great Lakes and can be\nstudied with smaller logistical budgets. Comparative studies of long-term changes between the Great Lakes\nand other lakes of the world may be possible and would strengthen assessment of global change patterns.\nThe goal is to develop a comprehensive, integrated, interdisciplinary research program on climate change\nand variability in large lakes.\n44","Great Lakes Environmental Research Laboratory\nAccomplishments FY 92\nNorth American Temperature Characteristics\nThe objective of this program is to (1) present the temperature patterns over the North American continent\nand particularly the Great Lakes for 10-year periods in the form of charts, compute differences between the\nperiods, and analyze changes and trends in the patterns; and (2) conduct a program of collaborative research\nwith the National Climatic Data Center to determine temperature trends. In FY 92, monthly temperature data\nfor the United States, Canada, and Mexico were obtained. The data sets were processed to computer files,\nordered by year, and then combined into a master North American set. A first cut of grid processing was\nestablished to translate these station data to monthly gridded data. Annual, 5-year, 10-year, and 1901-1987\naverages were computed. Software to produce temperature maps for North America was written and used\nto generate numerous draft charts.\nSnow Mapping and Characteristics\nSnowfall represents a vast reservoir of fresh water that, during the spring, contributes to the water supply\nof the Great Lakes or to the groundwater of the basin, thus affecting hydroelectric power generation,\ncommercial navigation, riparian owners, and recreational boaters. Heavy snowfalls are a natural hazard\nthroughout the region, and snowfall governs many recreational activities. The objectives of this program are\nto (1) compile monthly, yearly, and period of record snowfall maps for the Great Lakes basin and other areas\nof the world; (2) analyze the spatial and temporal variation of the snowfall; and (3) develop quantitative\nrelationships between Northern Hemisphere circulation patterns and Great Lakes snowfall/snow cover. In\nFY 92, final Great Lakes basin snowfall maps were produced for publication. Snow depth data were obtained\nfor the Republic of Mongolia, and snow depth maps were produced. A snow mapping system is being\ntransferred to scientists in that country.\nEffect of Climate Change on Large-Lake Ice Cycles\nThe duration and extent of ice cover on the Great Lakes have a major impact on the economy of the region\nby impeding commercial navigation, interfering with hydropower production and cooling water intakes, and\ndamaging shore structures. The ice cover also impacts the water balance of the lake by affecting lake\nevaporation and other heat and momentum transfers. The biology and chemistry of the lakes are also affected\nby the length and extent of ice cover. Climate change associated with global warming will possibly affect\nthe ice cover, which in turn will affect other physical, chemical, and biological processes. Objectives of this\nprogram include (1) developing improved models to better simulate the seasonal cycle of ice formation\nand loss on the Great Lakes, (2) estimating the Great Lakes ice cover for past winters using models, and\n(3) providing historical information on lake-scale ice cover trends, cycles, and variations on the Great Lakes\nthat will be useful in placing the ice cover of the 1990s and beyond in historical perspective. In FY 92, a\nconceptual lake-averaged thermodynamics ice cover model was linked with GLERL's lake evaporation model\nand calibrated using data on observed ice cover for Lakes Erie, Superior, Michigan, Huron, and Ontario. The\nlinked ice-evaporation model incorporates the effects of lake heat storage, surface energy balance, and winds.\n45","Climate Variability Using Chaotic Dynamics\nThe objective of this study is to explore the applicability of chaotic dynamics for the analysis of Great\nLakes climate changes as well as other physical and biogeochemical processes. In FY 92, we developed an\nanalysis program based on the widely used \"embedding\" method for calculating basic and generalized\ncorrelation dimensions to assess the chaotic characteristics of given time series. We also applied the\npreliminary analysis techniques to the study of Great Lakes monthly water level data as well as wind-wave\ntime series.\nThermal Structure Monitoring for Climate Change\nThe main objectives of this project are (1) to develop improved climatological information (via observa-\ntions, new instrumentation, and improved analysis) on the distribution and variability of coastal and offshore\ntemperatures and study their dependence on meteorological and hydrological forces with emphasis on\npotential changes in climate, and (2) to concurrently provide data for improving numerical models that can\nsimulate and predict the thermal structure in the lakes. In FY 92, all subsurface moorings were successfully\nretrieved and the data were recovered. A new surface TZ mooring is being tried at the Lake Michigan site.\nAll thermistor chain data were archived. -\nCurrent Velocity Profile Measurements in the Straits of Mackinac\nUsing Acoustic Doppler Current Profilers\nThe Straits of Mackinac connecting Lakes Michigan and Huron is an area of complex flow important\nin determining chemical and biological material flux, heat budgets, and lake flushing. This program is\n(1) measuring current profiles in strongly stratified shear flow; (2) relating these data to the numerous bilake\nhydraulic and hydrodynamic forcing processes; and (3) providing the framework for a future expanded study\nof the water volume transport process through the straits. In FY 92, initial monthly and 136-day net volume\nflow estimates were computed and an expanded program was developed to study strait dynamics and the\nphysical, chemical, and biological interactions with Lakes Michigan and Huron.\nImpacts of Climate Change on the Hydrology of the Great Lakes\nThe primary goal of this task is to determine potential impacts of future climate change on the hydrology\nof the Great Lakes basin, and specifically on net basin water supplies. Of particular concern is how various\nclimate regimes may affect variability from year to year in net basin supplies and in lake levels. In FY 92,\ntwo geographic areas, representing potential future climates in the Great Lakes basin, were chosen. They\nrepresent \"hot and dry\" and \"hot and wet\" possibilities for the Great Lakes. The density of meteorological\nstations needed for the hydrologic modeling effort and the data format and media for data transfer were\nidentified.\nWinter Ecology of Large Lakes\nEcology during winter and early spring in large lakes of the world is poorly studied in part due to logistical\nproblems. Extent of ice cover and optical properties of the ice affect ecosystem functions by affecting the\namount of photosynthetically available radiation reaching the water column and by stabilizing the water\n46","Great Lakes Environmental Research Laboratory\ncolumn. Growth and survival of freshwater phototrophic phytoplankton in winter depend on the amount of\nincident photosynthetically available radiation that penetrates snow and ice surfaces. This program involves\nlaboratory and field studies to determine the effects of ice cover on these and related processes by measuring\nthem during ice cover for selected sites on Great Slave Lake in the Canadian Northwest Territories, on the\nLaurentian Great Lakes, on Mongolian large lakes, and on certain small lakes for contrast. We have thus far\ncompleted a 1-week pilot sampling and a 3-week field study. Data analysis is under way.\nClimate Impacts on Large Lake Hydrology\nIn this program, which ended in FY 92 and has been reorganized into different tasks, accomplishments\ninclude compiling Russian data for the Caspian Sea Basin, collecting general circulation model (GCM)\nclimate-warming scenarios over the United States and Russia, and assessing GCM simulations to jointly\nstudy the hydrological aspects of climatic change over Russia.\nPlans FY 93\nContinue evaluation of linked lake ice-lake evaporation models.\nComplete analysis of climatic trends of ice formation and loss on Lakes Michigan and Mendota,\nincluding other possible locations in the continental United States where data are available.\nBegin to produce estimates of monthly lake-averaged ice cover for the Great Lakes to support a\nretrospective analysis of ice cover, water temperature, and fishery trends for the period of record.\nBegin study on Great Lakes ice cover climatic signatures at discrete depth ranges.\nBegin work on analysis of atmospheric circulation anomaly and Great Lakes ice cover anomaly.\nComplete net volume flux computations and assess their variability, and compare with the Lake\nMichigan water balance.\nRelate internal pressure gradients to current flow for the 2 days for which along- and cross-strait\ntemperature profiles are available.\nRetrieve and evaluate surface TZ mooring in the fall.\nBegin production of final North American temperature isoline charts.\nComplete transfer of snow mapping technology to Mongolian scientists.\nPOLLUTANT EFFECTS\nThis program pursues research to increase our understanding of the dynamics and effects of contaminants\nin the ecosystem. The conceptual framework for this research is the basic toxicological concept that effects\nare related to the attainment of a critical dose of contaminant for a specific duration. This research strives\nfor a generic understanding of contaminant dynamics and effects that can be applied to many different\nsystems, using sites and processes from the Great Lakes as specific examples. The research effort will\ncombine process studies and mathematical modeling to improve our understanding and ability to predict\ncontaminant fate and effects in the Great Lakes. The program focuses on toxic organic contaminants, with\nprimary emphasis on exposure and effects and a lesser emphasis on fate and assessment. Since the role of\ncontaminated sediments remains among the least well understood, but probably among the most important,\n47","of the exposure pathways, much of the current research is focused on sediment-associated contaminants and\nexposure to benthos.\nAccomplishments FY 92\nContaminant Effects and the Relationship to Exposure\nThis project focuses on developing the relationship between contaminant exposure and contaminant effects\non biota. To accomplish this goal, new bioassays will be developed and the body burdens required to elicit\nthe effects of these contaminants will be followed. In FY 92, Diporeia spp. were exposed to pyrene-\ncontaminated sediments, and both mortality and pyrene accumulation were followed. The lethal body burden\nfor Diporeia was 9,4 umol A similar experiment was performed with Lumbriculus variegatus; however,\nthe doses were not high enough to produce sufficient mortality to determine an LD50. Mortality and\navoidance bioassay data using Saginaw Bay and Saginaw River sediments were combined and analyzed as\na preliminary assessment of sediment contamination in this system. Solid-phase bioassays using Diporeia\nspp. were performed on sediments from the Raritan Estuary and Saginaw River to evaluate the extent of\ntoxicity reduction achieved by one treatment technique under evaluation. Raritan Estuary sediments were\ncollected as part of the National Status and Trends Program; Saginaw River sediments were provided by the\nCorps of Engineers as part of the U.S. Environmental Protection Agency (EPA) Assessment and Remediation\nof Contaminated Sediments Program.\nPhysical and Biological Diagenetic Processes in Sediments\nThis research examines feeding, burrowing, and other locomotive activities of benthic invertebrates that\ncontribute to sediment bioturbation and the effect of contaminants on these processes. The effect of\nbioturbation processes on porosity, particle size distribution, and distribution of organic matter including\ncontaminants is also examined. In FY 92, the reworking rates, an estimate of the rate of bioturbation, for\nseveral marine invertebrates were determined. Further, the reworking rates for selected marine benthic\nassemblages were investigated using intact cores collected from Tampa Bay, Florida. Bioturbation rates were\ngreatest for sediments containing the more diverse assemblages and for sandier sediments. A range-finding\nstudy of the effect of DDT on Heteromastus filiformis feeding was performed in preparation for the\nexamination of the effect of DDT on bioturbation rate.\nParticle Transport and Contaminant Cycling in the Upper Great Lakes\nThe objectives of this program are (1) to collect settling material in Lakes Michigan, Huron, and Superior;\n(2) to estimate mass and organic carbon fluxes from these trap samples; (3) to measure the decomposition\nrate of substrate organic matter; and (4) to measure a suite of hydrophobic organic compounds (HOCs) and\nestimate fluxes and recycling rates. In FY 92, samples were analyzed and mass fluxes were calculated.\nCarbon has been analyzed on some samples.\n48","Great Lakes Environmental Research Laboratory\nLong-Term Trends in Benthic Populations\nThe objectives of this project are to determine trends in benthic populations in selected areas of the Great\nLakes, and, if trends are detected, determine the most probable reasons for the changes observed. In FY 92,\nall samples collected in Saginaw Bay in 1987-88 were processed. This includes the identification and length\nmeasurements of all oligochaetes. Length measurements of Diporeia in samples collected in southern Lake\nMichigan in 1986-87 were initiated. Samples were collected in spring, summer, and fall at 40 stations in\nsouthern Lake Michigan. In addition, three extra samples were collected at 10 stations on each sampling\ndate. These samples will be given to personnel from the Canadian Center for Inland Waters for processing\nas part of the EPA's E-Map agreement.\nBioavailability of Sediment-Associated Toxic Organic Contaminants\nThis program seeks to (1) determine the assimilation efficiency of the Great Lakes amphipod Diporeia sp.\nfor ingested sediment-associated organic pollutants; (2) continue to develop the data required to improve the\nparameterization of a mechanistic bioaccumulation model; (3) validate the kinetics data obtained with\nlaboratory-manipulated sediments by exposing Diporeia sp. to field-collected sediments containing similar\ncontaminants; and (4) continue to develop simulation models for sediment-associated toxicants to better\nunderstand the bioavailable sources within the sediments and determine if transfer of sediment-associated\ntoxicants to the food chain is significant. In FY 92, methodology to measure the assimilation efficiency of\norganic contaminants from ingested sediment was investigated. Examination of the extent of exposure for\nbenthic organisms exposed to differing representation of sediment, whole sediment, interstitial water, and\n(4:1) elutriates, suggests that the organisms in the whole sediment accumulate more compound and the\ncontaminant in the sediments is much more available. The potential use of polydimethylsiloxane (PDMS)\n51\nas a tracer of contaminant assimilation is under investigation. This material may be a better tracer than Cr\nfor the organic contaminants. The importance of organic carbon as a tracer of contaminants in sediments\nwas examined by exposing Diporeia to sediments collected from several sites in Lake Michigan.\nBioenergetics of the Great Lakes Amphipod Diporeia sp.\nThe overall project objective is to obtain a detailed energy (carbon flow) budget in Diporeia sp. In FY 92,\nestimates of the annual and seasonal carbon budgets for Diporeia in Lake Michigan were completed. Work\ncontinued on the parameterization of the amphipod bioenergetics model using the available literature and the\nresults of the long-term trends and carbon budget analyses.\nPlans FY 93\nBegin to process benthic samples collected in southern Lake Michigan in 1992.\nContinue to process benthic samples collected in Whitefish Bay.\nComplete marine bioturbation experiments with DDT.\nComplete marine bioturbation experiments employing multiple-size particles with multiple tracers.\nBegin studies on the effects of sediment composition of the bioturbation process employing L.\nvariegatus.\n49","Continue to pursue the factors that affect the assimilation efficiency for ingested organic contami-\nnants from sediments, including sediment composition and differences among benthic species.\nContinue studies to determine the relative importance of exposure to whole sediment, interstitial\nwater, and elutriate on biological uptake and accumulation.\nDevelop methodology to examine the bioaccumulation of PCB and PAH congeners in Diporeia using\nfield-collected sediments and analyze selected samples.\nComplete analysis of carbon in particle transport tasks.\nComplete the sample and data analyses of the pyrene exposure performed last year to examine the\naccumulation and toxicity of pyrene in Diporeia and Lumbriculus.\nPerform a toxicity and accumulation experiment with phenanthreen of fluoranthene using Diporeia.\nContinue to work on the calibration of the Diporeia 28-d mortality bioassay to standard toxicants.\nDevelop analytical methodology for the measurement of PAHs and PCBs by gas chromatography-\nmass spectrometry (GC-MS) and GC electron capture detection (ECD).\nExamine the time course of solute extraction from sediments as a function of supercritical fluid\ndensity, solvent modifiers, and temperature.\nCompare the time course of extraction of laboratory-dosed, isotopically labeled compounds with that\nof compounds from field-contaminated sediments.\nCompare the uptake clearance rates of toxicants in field-contaminated sediments with those of\nlaboratory-dosed sediments for Diporeia sp.\nMARINE HAZARDS AND WATER MANAGEMENT\nGreat Lakes water is used for drinking, power generation, commercial shipping, and recreation, and it\nsupports an extensive commercial and sport fishery. Both natural (evaporation) and anthropogenic (diver-\nsions, consumption) influences threaten this valuable resource. Astute water management must be practiced\nto preserve the Great Lakes water supply. Portions of this program relate to prediction, climatology, statistics\nfor decision making, process studies, and interfaces with policy and decision makers. Marine hazards are a\nresult of a variety of environmental phenomena. Such hazards pose threats of loss of lives or property and\nsocial or economic disruption. Large waves, high and low lake levels, heavy snowfalls, ice, and erosion are\nsignificant hazards in the Great Lakes system and (with the exception of low lake levels) in other coastal\nareas as well. Human-caused hazards also pose serious threats, especially spills of petroleum products and\nchemicals. This program is providing models and other service products to assist in marine hazard prediction,\nemergency response, damage prevention and reduction, and more effective management of water resources.\nAccomplishments FY 92\nGreat Lakes Evaporation and Heat Storage\nThis program seeks to (1) derive lake surface temperature and cloud cover models using NOAA and\nGeostationary Observational Environmental Satellite (GOES) data; (2) classify and interpret lake surface\ntemperature patterns with special respect to weather situations; (3) develop a lake surface temperature model\non the basis of NOAA satellite data to derive surface temperature patterns when no satellite data are available;\n50","Great Lakes Environmental Research Laboratory\nand (4) develop and refine spatially distributed models of the heat fluxes at the lake surface using satellite\nand meteorological data, including a model to determine lake evaporation. In FY 92, new cloud-testing\nalgorithms were under development to enable automatic cloud masking of the available NOAA CoastWatch\ndata. Algorithms were developed to correlate temperature images from different dates and to correlate\ntemperature images with other spatial data sets (bathymetry, for instance).\nGreat Lakes Hydrology and Ice Data Bases\nThis program develops and maintains historical Great Lakes hydrology and ice cover data bases. It\ndevelops and maintains geographic information data bases of the Great Lakes basin and links the hydrology\nand ice cover data bases with the geographic data bases for spatial analysis. In FY 92, we began digitizing\nhistorical pre-1948 monthly precipitation data for the Great Lakes states, established Internet computer\ncommunications between the GLERL computer network and other computer networks for more efficient\ntransfer of hydrometeorological data, completed and distributed an International Great Lakes Datum\nbrochure, and collected and archived historical Great Lakes ice charts from the NOAA/Navy Joint Ice Center\nfor the winter of 1991-1992.\nLake Circulation and Thermal Structure Modeling\nThe objectives of this project are (1) to develop and test improved hydrodynamic models that can simulate\nand predict the three-dimensional structure of currents and temperatures in the Great Lakes; and (2) to extend\nthe models to simulate and predict the transport and diffusion of pollutants and nutrients, and participate in\ncoupling these models to aquatic ecology and water quality models. In FY 92, routine operation of the Great\nLakes Forecasting System at Ohio State University was accomplished and techniques were developed for\nanalysis of marine winds. Advanced Very High Resolution Radiometer (AVHRR) sea-surface temperature\n(SST) data and water level data were all incorporated into the prototype Great Lakes Forecasting System.\nGreat Lakes Water Level Statistics for Decision Making\nThe long-term objective of this project is to develop improved water level statistics that reflect (1) existing\nhydrologic and hydraulic conditions; (2) the long lag response of the lakes to meteorologic variability; (3)\nsecular changes in climatic regimes; and (4) the needs of diverse Great Lakes decision makers. In FY 92,\nprogress was made by (1) evaluating appropriate time series models of net basin supplies and exploring the\nproperties of the historical data; (2) developing a stochastic evaporation time series model; (3) creating a\nregulations and routing model capable of simulation of long series of water levels; and (4) assessing water\nlevel information needs, developing decision-making techniques, and identifying of future statistical products.\nGreat Lakes Evaporation, Forecasting, and Simulation\nIn this program, which ended in FY 92 and has been reorganized into different tasks, accomplishments\ninclude the following: compared GLERL and Corps of Engineers net water supply forecasts, determined\nprobabilistic outlook methodology for Great Lakes hydrology, integrated one-dimensional flow routing\nmodels for the St. Lawrence River, continued improving the quality of the hydrometeorological data base,\nfinished building the hydrometeorological station data base, completed Great Lakes response simulations to\n51","extreme climate scenarios, developed and distributed a set of lake levels and flows that reflect a consistent\nhydraulic regime in the Great Lakes-St. Lawrence River system, developed estimates of present consumption\nof Great Lakes water based on data collected by the Great Lakes Commission and U.S. Geological Survey,\nand investigated the pre-1900 St. Clair River flow regime by using measurements and data from dredging\nbetween 1860 and 1902.\nObjective Analysis of Great Lakes Marine Meteorological Observations\nThe main objective of this project is to develop and test improved techniques for objective analysis of\noverwater meteorological fields and to apply these techniques to practical problems of hindcasting and\nforecasting winds, waves, storm surges, and lake circulation. In FY 92, Fleet Numerical Oceanographic\nCenter (FNOC) Field by Information Blending and Smoothing (FIBS) winds were compared to wind fields\nanalyzed by nearest-neighbor and inverse distance weighting schemes. When used to drive a Lake Erie storm\nsurge model, smoothed nearest-neighbor wind fields appeared to provide the most realistic storm surge\nsimulations.\nAssessment of Shallow-Water Effects on Wind Waves\nUsing field measurements, data analyses, analytical techniques, and numerical models, this program seeks\nto (1) quantitatively assess the importance of shallow water effects on wind waves in the Great Lakes;\n(2) identify as well as quantify the circumstances and locations in which shallow water effects have a\nsignificant impact on deep water waves; and (3) improve understanding and prediction techniques of shallow\nwater waves. In FY 92, we successfully developed preliminary wavelet transform data analysis programs.\nPlans FY 93\nEvaluate regional coastal meteorological forecasts for the Great Lakes based on the National\nMeteorological Center's (NMC) Eta model.\nTest NMC regional forecasts for application to the operational Great Lakes wind wave forecast\nprogram at the Weather Service Forecast Office in Cleveland and for use in the Great Lakes\nForecasting System (three-dimensional hydrodynamic model) in collaboration with Ohio State\nUniversity.\nAttempt to simulate the three-dimensional development of stratification, including thermal bar\ndynamics and midlake vertical heat advection.\nEvaluate Great Lakes Forecasting System Lake Erie nowcasts for 1992.\nBegin Great Lakes Forecasting System 2-day forecasts for Lake Erie in 1993.\nExtend Great Lakes Forecasting System nowcasts to another lake, probably Michigan or Ontario.\nPerform tests to show the effect of including or excluding overlake wind observations in the objective\nanalysis.\nTest the three-dimensional circulation model with idealized topography against known analytic\nsolutions for steady-state barotrophic circulation, internal Kelvin wave dynamics, Ekman layer\ndynamics, and free surface normal modes.\n52","Great Lakes Environmental Research Laboratory\nCouple existing large-scale basin hydrology and lake evaporation models with the atmospheric model\nand transfer to the Air Resources Laboratory.\nDevelop and refine models to relate meteorological point measurements to satellite images.\nDevelop and refine spatial heat flux models, including evaporation. Classify surface temperature\npatterns.\nDevelop a model to assess cloud cover, height, and surface temperature patterns using GOES data.\nDevelop a model to calculate the incoming radiation on the basis of cloud cover and height from\nGOES satellite and meteorological data.\nModify the data for stations adjacent to the lakes based on average lake effects.\nPrepare climate data for each geographic region at the Midwest Climate Center in Urbana, Illinois,\nfor later use at GLERL.\nDetermine the areal average meteorology for all variables of interest by using Thiessen weighting\nalgorithms.\nOrganize the reduced data for efficient processing with hydrology models.\nReview underlying theory and program code of the existing runoff model.\nDefine land surface parameterizations of next generation runoff.\nAcquire land surface spatial data.\nComplete digitizing historical monthly precipitation data and station history data.\nBegin digitizing historical pre-1948 temperature data for Great Lakes states.\nInitiate acquisition of Geographic Information System (GIS) data bases.\nDefine climate regimes as indicated by trends in meteorological and water level data.\nReview possible approaches for stochastic generation of net basin supply components.\nNUTRIENT-ENHANCED COASTAL OCEAN PRODUCTIVITY\nThe Nutrient-Enhanced Coastal Ocean Productivity (NECOP) activity is one of a series of NOAA-wide\nprograms dealing with major problems in the coastal ocean. The central hypothesis is that increased nutrient\ninput from the Mississippi River has led to increased productivity, with undesirable consequences. GLERL\nis involved in several studies that have been under way for 2 years.\nAccomplishments FY 92\nThe Fate and Effects of Riverine (and Shelf-Derived) Dissolved Organic Carbon and Nitrogen\non Mississippi River Plume-Gulf Shelf Processes\nThe objectives of this study are to define the chemical and isotopic composition of riverine and Mississippi\nRiver Plume Gulf Shelf (MRP/GS) dissolved organic nitrogen (DON) and determine the biological reactivity\nof dissolved organic carbon (DOC) and DON. Isotopic analysis allows us to distinguish between riverine\ninput nutrients and shelf-derived nutrients and also to measure rates of nutrient recycling. In FY 92, our high\n53","15\nperformance liquid chromatography (HPLC) method to determine the ratio of NH4 to total NH4 was\nautomated and improved to make it a practical and precise method for isotope dilution experiments being\nconducted in the Gulf of Mexico. Ammonium regeneration rates were higher in the summer than in the\nwinter. They were also higher in surface waters near the Mississippi River outflow compared to stations\nfarther offshore in the plume or in the river. In the productive regions, ammonium regeneration rates were\nhigher in the upper portion of the water column than in regions below the euphotic zone. Methods were\ndeveloped to concentrate and manipulate bacteria from seawater to assess their importance relative to other\nheterotrophic organisms in regenerating ammonium. Measurement of ammonium regeneration rates, in\nconjunction with manipulation of microbial biomass, indicated that heterotrophic bacteria regenerated a\nsignificant portion (50%) of the MRP but were responsible for a smaller fraction of total regeneration at\nother sites.\nSuspended Sediment on the Louisiana Continental Shelf: Concentrations, Compositions, and\nTransport Pathways\nThis completed study had three major objectives: (1) to map the spatial distribution and, to the extent\npossible, the temporal variations of SPM concentrations and composition in the MRP and adjacent shelf\nwater; (2) to determine, within the limits imposed by the budget, the importance of lateral transport of SPM\nin the study region; and (3) to determine the relationships between the existence and extent of nepheloid\nlayers and other characteristics of the water column such as vertical temperature and salinity structure,\nambient current velocity, wave activity, and river discharge.\nIn FY 92, all available data were processed and plotted. Only one resuspension event occurred during the\nsecond cruise at station 1.\nRetrospective Analysis of Nutrient-Enhanced Coastal Ocean Productivity in Louisiana\nContinental Shelf Sediments\nThe objectives of this program are to (1) identify areas in the coastal region where sediments with coherent\ngeochronologies of approximately 200 years can be collected; and (2) examine the selected cores for tracers\nof past water and ecosystem conditions (e.g., carbon, nitrogen, diatom frustules, and stable isotopes). In FY\n92, we completed analysis of 1990-91 cores for lipids and lignins. These results confirmed our stable isotope\nresults showing the presence of increased levels of coastal production in recent sediments. We also\nparticipated in a major sediment cruise in April 1992. Cores were collected to extend our program into pore\nwater and diagenesis work. These data are partially analyzed.\nBuoyancy and Nutrient Exchange in the Mississippi River Outflow Region\nThe focus of research is the examination of processes contributing to the advective exchange of environ-\nmentally significant fields in the Mississippi River outflow region. The primary objectives of this study are\nto establish a historical relationship between buoyancy and nutrient fluxes for the Mississippi-Atchafalaya\nRiver (MAR) system and to quantitatively determine the scales of variability for buoyancy and nutrient fields\nin a shelf region dominated by riverine sources. In FY 92, we continued field work and analysis of both the\nhistorical data base and new data. CTD data from the May 1992 cruise were processed and submitted to the\nNECOP data base.\n54","Great Lakes Environmental Research Laboratory\nPrimary Production and Vertical Flux of Organic Carbon\nThis research is addressing the following objectives: (1) characterize photoautotrophic community\ndynamics in relation to optical conditions, nutrient inputs, and other aspects of the physical and chemical\nenvironment; (2) examine the relationship between phytoplankton production, growth, and biomass, and the\nvertical export of fixed carbon from the surface waters of the MRP/IGS (Inner Gulf Shelf); and (3) develop\nconceptual and predictive models that describe the production and fate of fixed carbon as a function of optical\nconditions, nutrient inputs, and other environmental variables. In FY 92, we completed two research cruises\nand continued development and implementation of the production model.\nPlans FY 93\nIntegrate current velocity measurements taken with an Acoustic Doppler Current Profiler with other\nNECOP data.\nAttempt to model a resuspension event with a one-dimensional model provided by the Pacific Marine\nEnvironmental Laboratory (PMEL).\nParticipate on final NECOP cruises and process data.\nComplete implementation of the Great Lakes Production Model in the NECOP study area and use it\nto model primary production in the northern Gulf of Mexico.\nProcess results from the April 1992 cruise on heterotrophic nitrogen dynamics in the MRP.\nWork on new approaches to determine nitrogen regeneration rates using capillary zone electropho-\nresis and apply them to Gulf of Mexico experiments.\nContinue analysis of cores collected on the April 1992 cruise and the incubation experiments begun\non that cruise.\nPossibly participate in another sediment/benthic remineralization cruise in the fall of 1993.\nBegin modeling pore water and diagenesis data.\nGREAT LAKES COASTWATCH\nCoastWatch is a NOAA-wide program within the Coastal Ocean Program. As a CoastWatch Regional\nSite, GLERL is establishing operations of the Great Lakes Regional National Ocean Communications\nNetwork (NOCN) Node (RNN), identifying regional CoastWatch users and their NOAA data needs, and\nsupplying useful products to participants in the Great Lakes Coast Watch Program.\nAccomplishments FY 92\nGreat Lakes CoastWatch Product Development and Research\nThe objectives of this task are to evaluate and help validate Great Lakes CoastWatch products, provide\ninput to the National Environmental Satellite, Data, and Information Service (NESDIS) for product needs\nand development, and research and develop related products and uses specific to the Great Lakes region using\n55","CoastWatch data. In FY 92, we (1) participated in verification of new SST algorithms for the Great Lakes;\n(2) began receiving Synthetic Aperture Radar (SAR) workstation hardware and software and some Earth\nResources Satellite (ERS-1) SAR data; (3) completed preliminary evaluation of a Landsat Thematic Mapper\n(TM) scene for use in chlorophyll mapping; and (4) incorporated 15 federal, state, and local agencies and\nacademic institutions into the program as local CoastWatch sites.\nPlans FY 93\nComplete implementation and testing of SAR workstation software and evaluation of CoastWatch\nSAR data.\nContinue analysis of Landsat TM scene for use in Great Lakes chlorophyll mapping.\nContinue verification and analysis of Great Lakes SST algorithms.\nContinue to incorporate interested federal, state, and local agencies and academic institutions into\nthe program as local CoastWatch sites and identify regional product development and research needs.\nImplement and test CoastWatch workstation.\n56","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nGEOPHYSICAL FLUID DYNAMICS LABORATORY\nPrinceton, New Jersey\n(609)452-6502\nJ. D. Mahlman, Director\nThe Geophysical Fluid Dynamics Laboratory (GFDL) is engaged in comprehensive, long-lead-time\nresearch fundamental to NOAA's mission. The goal of this research is to expand the scientific understanding\nof the physical processes that govern the behavior of the atmosphere and the oceans as complex fluid systems.\nThese systems can then be modeled mathematically and their phenomenology can be studied by computer\nsimulation methods. In particular, GFDL research concerns the following:\nThe predictability of weather on large and small scales.\nThe structure, variability, predictability, stability, and sensitivity of global and regional climate.\nThe structure, variability, and dynamics of the ocean over its many space and time scales.\nThe interaction of the atmosphere and oceans and how the atmosphere and oceans influence and are\ninfluenced by various trace constituents.\nThe Earth's atmospheric general circulation within the context of the family planetary atmospheric\ncirculations.\nThe scientific work of the Laboratory encompasses a variety of disciplines including meteorology,\noceanography, hydrology, classical physics, fluid dynamics, chemistry, applied mathematics, and numerical\nanalysis.\nResearch is also facilitated by the Atmospheric and Ocean Sciences (AOS) program, which is a collabo-\nrative program at GFDL with Princeton University. Under this program, regular Princeton faculty, research\nscientists, and graduate students participate in theoretical studies, both analytical and numerical, and in\nobservational experiments in the laboratory and in the field. The program is supported in part by NOAA\nfunds AOS Program scientists may also be involved in GFDL research through institutional or international\nagreements.\n57","WEATHER SERVICE\nSynoptic-scale weather forecasts have improved considerably over the past two decades because of the\ndevelopment of numerical models that include more of the physical processes of the atmosphere, have higher\nspatial resolution, and parameterize turbulent processes more accurately. Successful forecasts for periods up\nto 5 days are now routine, and the limits of atmospheric predictability have been extended to several weeks.\nHowever, quantitative forecasts of precipitation remain elusive. For smaller spatial scales, there has been\nconsiderable progress in determining the mechanisms that generate severe storms, in explaining how\nmesoscale phenomena interact with the large-scale flow, and in simulating the movement, genesis, growth,\nand decay of hurricanes.\nThese successes in the extension of atmospheric predictability have encouraged GFDL to ask more\nchallenging questions. For example, can aspects of the weather be predicted on time scales of months to\nyears? Are mesoscale weather systems and regional-scale precipitation patterns predictable? If SO, to what\nextent is the accuracy dependent on the prediction of the ambient synoptic flow? Research to develop\nmathematical models for improved weather prediction will also contribute to the understanding of such\nfundamental meteorological phenomena as fronts, hurricanes, severe storms, planetary waves, and tropo-\nspheric blocking.\nAccomplishments FY 92\nThe simulated distributions of precipitation, clouds, and soil moisture were dramatically improved by using\nfiltering techniques to reduce the distortions associated with the spectral representation of model orography.\nA Lanczos filter was applied to smooth the model orography, as well as to the grid-point cumulus\nparameterization results. As a result, negative values of mixing ratio, which have been an annoying problem\nfor spectral models, have been eliminated for the most part, and the ripples in the surface pressure, produced\nmostly by the Andes and the Antarctic highlands, have been largely removed.\nMajor efforts were expended on the improvement of the air-sea coupled model, focusing on two aspects\nof its simulation capability, the El Niño-Southern Oscillation (ENSO) and the global sea-surface temperature\n(SST) distribution. Model sensitivity tests involving atmospheric parameters such as surface winds, evapo-\nration, and incoming shortwave radiation were made. So far, the surface wind stress in the eastern tropical\nPacific has been found to be the most influential parameter for reproducing the annual cycle and interannual\nvariability of SST. Also, the impact of the horizontal resolution of the atmospheric general circulation model\non reduction of the SST bias has been established. For example, the cold bias at the Equator was reduced by\na factor of 1.7 by increasing the resolution from R21L9 to T42L18.\nOne of the requirements for a useful ensemble forecast is that the ensemble members should cluster about\nthe true solution. To achieve this objective, the dynamical and thermodynamical balancing of the initial\nconditions that are perturbed, based on Monte Carlo methods, is an important process. For this purpose, the\ncapability of two methods of initialization was tested; one method is a nudging method and the other is a\nfull-fledged data assimilation approach.\nAn automated GFDL hurricane prediction system was established by assembling the procedures of data\nacquisition, model initialization, and time integration of the hurricane model into one system. This system\ncan now run in near real time. Hurricane prediction experiments using the automated system were performed\nfor seven cases of Atlantic hurricanes and for one case of a tropical cyclone in the Australian region. The\nresults indicated dramatic improvement in track forecasts as well as the feasibility of forecasting storm\nintensity.\n58","Geophysical Fluid Dynamics Laboratory\nThe question of why tropical cyclones do not form over land surfaces, such as a tropical rainforest, a\nfundamental question in tropical cyclogenesis, was studied through a series of idealized experiments using\nthe hurricane model with improved treatment of radiation and land surface conditions. It was found that the\nsmallness of the land's \"thermal property\" (defined as the square root of the product of the heat capacity and\nthe thermal conductivity) of the soil hindered storm formation.\nUsing a joint hurricane-ocean model, the impact of hurricane-ocean feedback processes on the behavior\nof tropical cyclones was investigated. Over the ocean, with the SST set to 302 K at the initial time, the storms\nin different basic easterly flows deepened to nearly the same intensity when the interaction was included.\nThe importance of downstream development for baroclinic waves was demonstrated in recent studies.\nUsing a three-dimensional primitive equation model, it was shown that the convergence/divergence of\nageostrophic geopotential fluxes provides a major source/sink of kinetic energy for both downstream and\nupstream development of baroclinic waves, and can play a dominant role during all stages of wave\ndevelopment.\nThe success with which geopotential fluxes have been used in case studies to indicate regions of kinetic\nenergy growth and decay suggests that those fluxes offer considerable potential as a powerful diagnostic tool\nfor predicting the growth and decay of systems.\nRecent simulations of storm tracks using an idealized model have shown that the existence of a localized\nsource of enhanced baroclinicity does not necessarily lead to a localization of eddy activity. Energy radiated\ndownstream by eddies generated in the high-baroclinicity region will trigger and sustain eddies in the\nlow-baroclinicity region downstream. These results represent a fundamental difference between downstream\ndevelopment and normal-mode cyclone life cycles.\nA new mechanism for lee cyclogenesis was proposed, based on a series of experiments in which it was\nfound that the interruption of the warm ascending branch of a baroclinic wave by a topographic barrier will\nproduce a low pressure system south of the barrier, due to the warm advection induced by the mountain\nanticyclone.\nPlans FY 93\nInvestigation of a scheme that reduces noise generated by cumulus convection will be continued.\nThree experiments that evaluate the influence of atmospheric subgrid-scale parameterizations will\nbe summarized. The \"bucket\" and a more advanced surface hydrology will be compared.\nA random cloud model will be tested. The development of a working version of the mesoscale eta\nmodel with cloud physics will be completed. Along time integration with specified satellite-derived\nclouds will be carried out.\nA C-grid option will be added to the grid point model.\nA version of the GFDL Modular Ocean Model (MOM) with an implicit free surface will be\nimplemented. Lateral boundary conditions will be added to the MOM.\nThe noise-reduced model with lower resolution, coupled with the ocean model, will be investigated.\n1° X 1° latitude grid size ocean model will be tested in an air-sea coupled mode.\nThe compatibility of the MOM's surface pressure with that derived from satellite altimeter data will\nbe investigated. An algorithm to assimilate altimeter data will be developed. The ocean data\nassimilation procedure will be repeated with Tropical Ocean Global Atmosphere (TOGA) data\nincluded.\nThe nine runs using the medium-resolution atmospheric model will be completed, and the results\nwill be analyzed and compared with observations. The study on the reproducibility of multiple runs\n59","will be repeated, using a 40-year SST data set. The investigation of methods to estimate the\nuncertainty in the atmospheric analysis will be continued. Ensemble forecasts will be performed,\nusing a set of about 300 perturbed initial conditions. As a reasonable way of stratifying the ensemble,\ntwo states of atmospheric circulation, zonal-type flow and blocked patterns, will be investigated.\nThe automated hurricane prediction system will be further evaluated by its application to Atlantic\nand Eastern Pacific hurricanes in the 1992 season.\nA study to investigate the effects of tropical cyclones on the evolution of the surrounding environment\nwill be carried out. This issue is one side of the twofold aspect of scale interaction.\nAdditional case studies will be initiated to better understand the role of geopotential fluxes and\nbaroclinic conversion in the development of cyclones. From the new perspective gained SO far, the\nexplosive development of storms will be analyzed to identify the roles played by localized baroclinic-\nity and the decay of upstream systems.\nAlternative time-filtering approaches will be employed to identify the role of downstream develop-\nment in the formation and maintenance of storm tracks.\nStudy of the role of surface heat and momentum fluxes in the intensification of extratropical cyclones\nwill continue. New case studies will be performed to assess the relative importance of these fluxes\nin atmospheric preconditioning and cyclone evolution.\nCLIMATE\nThe purpose of climate-related research at GFDL is twofold: to describe, explain, and simulate mean\nclimate and climate variability on time scales from seasons to millennia; and to evaluate the climatic effect\nof human activities such as the release of carbon dioxide (CO2) and other gases in the atmosphere. The\nphenomena that are studied include the following: large-scale wave disturbances and their role in the general\ncirculation of the atmosphere; the seasonal cycle, which must be defined before departures from that cycle\n(interannual variability) can be understood; interannual variability associated with phenomena such as ENSO;\nvery long term variability associated with the ice ages; and the meteorologies of various planets, the study\nof which enhances the scientific perspective on terrestrial meteorology and climate. To achieve these goals,\nboth observational and theoretical studies are necessary. Available observations are analyzed to determine\nthe physical processes by which the circulations of the oceans and atmospheres are maintained. Mathematical\nmodels are constructed to study and simulate the ocean, the atmosphere, the coupled ocean-atmosphere-land\nsurface-cryosphere system, and various planetary atmospheres.\nAccomplishments FY 92\nAnalysis of a 1000-year integration of the coupled ocean-atmosphere model indicates the following:\nThere is substantial interdecadal variability of the model thermohaline circulation in the North\nAtlantic Ocean. These fluctuations, with a time scale of approximately 40-50 years, are related to\nlarge-scale changes in the temperature, salinity, and density structure of the model North Atlantic,\nand may have important implications for atmospheric variability on interdecadal time scales.\nSurface temperature variability tends to be larger and more persistent in the neighborhood of deep\nand intermediate water formation in the ocean.\n60","Geophysical Fluid Dynamics Laboratory\nRadiative-convective equilibria were obtained using a two-dimensional model with resolved moist\nconvection in which the radiative transfer is fully interactive with the predicted moisture and cloud fields.\nThe model produces a basic flow oscillation with a period of approximately 60 days. The predicted planetary\nalbedo decreases with increasing surface temperature. This implies a possible positive cloud-radiation\nfeedback in the climate system.\nExperiments designed to measure the feedback between the Earth's climate and vegetation on land revealed\na positive feedback at low latitudes due to the vegetation's surface albedo effect, but not at middle and high\nlatitudes. There is also some positive feedback due to the surface roughness at all latitudes, but little feedback\ndue to soil moisture field capacity.\nThe GFDL SKYHI atmospheric model was completely rewritten in a fully modular form. This new version\nallows for far simpler user access, full separability of physics packages, use of higher-order advection and\ndiffusion schemes, and a completely separable multiple-trace constituent package for climate and chemistry\nstudies. This recoding has been put in a form that allows access of this model to the new generation of\nmassively parallel processor (MPP) systems.\nThe stratospheric climatology of the SKYHI model was extensively evaluated at 1°, 2°, and 3° latitude grid\nspacing versions. The comparison with observations shows generally good agreement that improves as the\ngrid size is decreased. Overall, the winter stratosphere agreement with observations is remarkably good in\nthe Northern Hemisphere, but important deficiencies remain in the Southern Hemisphere.\nThe SKYHI 3° latitude resolution model shows a highly realistic interannual climatology of sudden\nstratospheric warming events. Extended forecast experiments show that global sudden warming events\nbecome quite unpredictable if the model is initialized a month or more before the peak of the warming event.\nA radiative model study revealed that the effects of volcanic aerosol can modify the amount of surface\nclimatic forcing on the interdecadal time scale by an amount that is large relative to the incremental\ngreenhouse gas forcing. This shows that volcanic effects must be carefully considered when observational\nevidence of global warming signals is sought.\nA major study was completed, showing that the marked decrease of lower stratospheric ozone during the\n1980s implies a significant negative climate forcing for the Earth's surface. Although only a modest\ncorrection to the net increased greenhouse forcing during this period, the ozone loss effect does roughly cancel\nthe greenhouse warming effect of the increased chlorofluorocarbons, probably the root cause of the substantial\nozone decreases. This finding was a highlighted new result in the Intergovernmental Panel on Climate Change\n(IPCC) 1992 Supplement.\nThe landmark book Physics of Climate, which was in preparation for many years, was finally published\nin January 1992 by the American Institute of Physics. This 520-page book describes, among other topics,\nthe basic equations governing the climate system; the observed state of the atmosphere, ocean, and\ncryosphere; the global angular momentum; water, energy, and entropy cycles; interannual and interdecadal\nvariations; and the mathematical simulation of climate. It can be used as a graduate textbook on climate.\nThis publication represents a major investment of time and research effort by the Observational Studies Group\nat GFDL. So far, it has been favorably reviewed; a second printing is already in progress.\nThe global tropospheric and lower stratospheric temperature analyses for the period May 1958 through\nDecember 1989, produced at GFDL during the last two decades, have been adopted as the standard\natmospheric data to describe the state of the atmosphere and its temporal evolution for the 1992 Supplement\nto the IPCC Scientific Assessment.\nA series of atmospheric model experiments, performed as part of a NOAA/universities collaborative effort,\nyielded several phenomena that bear considerable resemblance to the observations. Of particular interest are\nthe temporal and spatial development of the Asian summer monsoon, the differences between the atmospheric\ncirculation in various parts of the globe during the spring and autumn seasons, and the decadal-scale variability\nin the occurrence of the teleconnection pattern associated with El Niño. The appearance of such features in\nthe model atmosphere offers promise that diagnosis of the model output and additional integrations of the\n61","coupled atmosphere-ocean models will enhance our understanding of the mechanisms contributing to these\nphenomena.\nIntercomparison of the output from a suite of coupled-model runs, which incorporate different aspects of\nthe air-sea interactions, indicates that a substantial portion of the coupling between SST and meteorological\nanomalies in the extratropics may be attributed to the atmosphere driving the ocean, whereas the influence\nof the ocean on the atmosphere appears to play a secondary role.\nPlans FY 93\nThe analysis of low-frequency variability in the coupled model of the atmosphere-ocean system will\nbe continued. Special emphasis will be placed on the role of the oceans in the interdecadal variability\nof climate.\nA detailed analysis of the direct sensitivity of surface water balance to soil water-holding capacity\nwill be conducted.\nA series of calculations will be performed with the resolved-convection, radiative-convective\nequilibrium model, testing the model's sensitivity to resolution, subgrid-scale parameterization,\ndomain size, and microphysical assumptions.\nTo explore the confusing issue of how the atmosphere responds to perturbations in SST, a series of\nlow-resolution integrations will be performed with the low-resolution atmospheric model, using\nversions with both realistic and idealized geometries.\nCalculations will be conducted with the dry dynamical cores of several atmospheric models (both\nspectral and gridpoint) at several resolutions, as a starting point in a systematic study of the merits\nand deficiencies of alternative atmospheric modeling frameworks.\nFurther development of the modular version of SKYHI will continue, with emphasis on generalizing\nit for climate studies and for computational testing on MPP systems.\nNew control integrations will be started with the SKYHI model that incorporate improved distribu-\ntions of ozone and clouds, along with inclusion of updated radiative transfer algorithms.\nExtensive analysis of the interannual variability of the simulated Northern Hemisphere stratospheric\ncirculation in SKYHI will be conducted.\nAnalysis of the climatic implications of stratospheric ozone loss will continue. Whenever possible,\ncomparisons will be made with observed temperature trends.\nThe study of the three-dimensional structure of the observed trends in temperature and humidity, and\ntheir possible connection with the greenhouse gases warming during the last 26 years, will continue.\nATMOSPHERIC QUALITY\nThe main goal of atmospheric quality research at GFDL is to understand the formation, transport, and\nchemistry of atmospheric trace constituents on regional and global scales. This involves attack on such central\nproblems as the following: the transport of quasi-conservative trace gases; the biogeochemistry of climatically\nsignificant long-lived trace gases, such as carbon dioxide, methane, nitrous oxide, and the chlorofluorocar-\nbons; the chemistry of ozone and its regulative trace species, such as the families of reactive nitrogen,\nhydrogen, chlorine, and hydrocarbons; and the effects of clouds and aerosols on chemically important trace\n62","Geophysical Fluid Dynamics Laboratory\ngases. Such research requires judicious combinations of theoretical models and specialized observations. The\nunderstanding gained will be applied toward evaluating the sensitivity of the atmospheric chemical system\nto human activities.\nAccomplishments FY 92\nThe GFDL Global Chemical Transport Model (GCTM) was used to evaluate the behavior of chemically\nreactive nitrogen (NO) components, NOx, HNO3, and PAN as transported species. This experiment reveals\nseveral new insights: (1) about 70-75% of fossil fuel emissions are deposited near their source regions, and\nthe remainder are exported to adjacent ocean basins; (2) fossil fuel sources dominate the observed HNO3\nsurface deposition in the extratropical North Atlantic; (3) much of the midtroposphere PAN and HNO3 levels\ncan be explained by fossil-fuel and stratosphere sources of NO; (4) the fossil-fuel source has only a minor\nimpact on NO levels in the Southern Hemisphere and remote tropics; and (5) away from source regions,\nPAN is a major component of fossil-fuel NO and dominates north of 45°N.\nThe effort continues on determining how much the ozone, at relatively unpolluted sites, is controlled by\nanthropogenic NO emissions. Adetailed model and observational analysis indicated that the Atlantic islands\nof Bermuda and Barbados have an ozone climatology that is essentially under the control of natural processes,\nsimilar to that seen at Samoa in the South Pacific, a clearly remote site.\nA continued comparison of the 1° latitude resolution SKYHI model with the recent polar stratospheric\naircraft expeditions revealed further insights. The model does an excellent job of simulating the very sharp\n\"wall\" of N2O gradient at the edge of the northern polar vortex. Unfortunately, the southern vortex edge is\nnot as well simulated, paralleling other documented dynamical deficiencies in the model's Southern\nHemisphere winter stratosphere. An indirect analysis leads to the additional conclusion that current chemical\nparameterizations of N2O photochemical destruction in the stratosphere are too weak.\nPlans FY 93\nSKYHI experiments with various levels of ozone chemistry will be started. These experiments will\nestablish a baseline for an accelerated effort in tropospheric and lower stratospheric chemistry, and\nits connection to ozone-climate interactions.\nReactive nitrogen simulations will be carried out in the GCTM for multiple species with all the\nnitrogen sources and hydrocarbon effects included.\nSKYHI transport studies will be performed with a suite of trace constituents: chlorofluorocarbon-11\nfor evaluating interhemispheric transport, reactive nitrogen for comparison with the previous-\ngeneration GCTM, stratospheric ozone to test \"natural\" ozone effects, and a biomass burning source\nfor testing transport in the topics.\nThe photochemistry of biomass NO emissions and O3 over the tropical ocean will be examined in\nthe context of regional transport.\n63","MARINE QUALITY\nResearch at GFDL related to the quality of the marine environment has as its objectives the simulation of\noceanic conditions in coastal zones and estuaries, the modeling of the dispersion of geochemical tracers\n(tritium, chlorofluorocarbons, etc.) in the world oceans, and the modeling of the oceanic carbon cycle and\ntrace metal geochemistry. For regional coastal studies, two-and three-dimensional models of estuaries, basins,\nand western boundary regimes are being developed. The response of coastal zones to transient atmospheric\nstorms and the nature of upwelling processes (which are of great importance to fisheries) are being studied\nwith a variety of models. Basin and global ocean circulation models are being developed for the study of the\ncarbon cycle and trace metal cycling.\nAccomplishments FY 92\nResults from numerical simulations of the Gulf Stream with a realistic regional model compared well with\nobservations and contributed to the understanding of dynamical processes, such as the separation of the Gulf\nStream from the coast and its interaction with topography. Forecast and nowcast skills were demonstrated\nfor the Gulf Stream region using a data assimilation scheme to assimilate satellite altimetry and SST data\ninto the model.\nThe ocean's capacity to take up anthropogenic CO2 has been estimated with an ocean general circulation\nmodel. The uptake estimate for the 1980 to 1989 decade (1.9 GtC per year) is in excellent agreement with\nother models, but significantly larger than the Climate Monitoring and Diagnostic Laboratory (CMDL)\nestimate of 0.3 to 0.8 GtC per year based on observations and an atmospheric model. The discrepancy has\nbeen explained as arising primarily from the fact that CMDL ignored the substantial net flux of carbon into\nthe ocean by rivers.\nA study of the potential response of atmospheric CO2 to perturbations in the ocean carbon cycle, such as\nthose that might result from enhancing new production by iron fertilization of the high-latitude Southern\nOcean, has been completed. The iron fertilization scenario could potentially have a significant impact on\natmospheric CO2 but the extreme conditions required to achieve a large impact would be difficult, if not\nimpossible, to satisfy. The impact of the Southern Ocean iron fertilization scenario on atmospheric nitrous\noxide levels is potentially quite large, increasing the flux by a significant factor (0.1 to 15.4 TgN per year),\ncompared to the present flux of 1.4 to 2.6 TgN per year. The same model was used to show that the potential\ngrowth of marine macroalgae as a sink for CO2 is minor.\nAn analysis of the ecosystem model of nitrogen cycling in the North Atlantic has been completed. This\nmodel can predict many of the observed features of the nutrient and chlorophyll distributions.\nA new set of simulations of the biological and chemical cycling of carbon through the water column were\ninitiated with a model of carbon's solubility pump, driven by the increase in the solubility of CO2 in cold\nwater. The combined effect of the solubility pump with the biological pump, which is driven by organic\ncarbon cycling, is being simulated. The model of the solubility pump explicitly includes total carbon and the\n13\n13C isotope, gas exchange, the carbonate species H2CO3, HCO3., and CO3, as well as the contributions to\ntotal alkalinity of dissolved silica, phosphate, water, and borate species.\nA reanalysis of thorium data from Station P in the North Pacific provided realistic estimates of the\nconcentration of sinking particles and of the magnitude of particle cycling rate constants. A compilation of\nthorium and particle data from the Nares Abyssal Plain in the northwest Atlantic was used to determine particle\ncycling rate constants throughout the water column.\n64","Geophysical Fluid Dynamics Laboratory\nA new carbon system measurement program was established this year to support the World Ocean\nCirculation Experiment (WOCE) Hydrographic Program by providing high precision carbon system meas-\nurements on their cruises.\n228\nFinal\nprocessing of Ra samples collected by the Ocean Tracers Laboratory during the North Atlantic\nTransient Tracers in the Ocean (TTO) experiment is nearly complete. Interpretation of these results is now\nunderway, including both classical methods as well as with numerical models. At the present time, the Ocean\nTracers Laboratory is the primary laboratory for collection and interpretation of 14 C in the U.S. Pacific WOCE.\nDuring FY 92, members of the laboratory participated in seven sampling cruises, mostly in midlatitude eastern\nPacific waters.\nPlans FY 93\nThe construction and evaluation of an operational coastal ocean prediction system for the U.S. east\ncoast will continue. Modeling of climatic effects on coastal regions and sea level change will be\ninitiated.\nA set of simulations of oceanic anthropogenic CO2 uptake will be carried out using the new ocean\ncarbon system model that is being developed with a more realistic representation of the biological\nand solubility pumps than used for the previous studies.\nA project will be initiated in collaboration with the Climate Dynamics group to calculate oceanic\nuptake of anthropogenic CO2 in coupled air-sea models of the climate response to increased\natmospheric CO2.\nResults of the tropical Pacific portion of the global equatorial ecosystem model will be analyzed and\nthe impact of El Niño will be simulated.\nA new effort is being undertaken to examine the feasibility of assimilating satellite ocean color\nobservations into the ecosystem model as a technique for using such data to obtain information on\ncarbon fluxes in the ocean.\nAn inversion of 234 Th, nitrogen, and carbon data from the Joint Global Ocean Flux Study North\nAtlantic Bloom Experiment will be attempted. This data set provides estimates of the change with\ntime of the activity of thorium isotopes and concentration of nitrogen and carbon. This data should\nhelp provide more precise estimates of carbon and particle cycling rate constants.\nThe ongoing reanalysis of oceanic nutrient observations will be completed to obtain new estimates\nof Redfield ratios.\nThe North Atlantic thermocline ventilation studies will be continued, with the possibility of\nextending the analysis to the South Atlantic, particularly to the region of the Agulhas retroflection\nand to the southwestern Atlantic.\nThe Ocean Tracers Laboratory will continue to participate in the WOCE program. This laboratory\nis currently scheduled for approximately 300 days of sea time for FY 93.\nOCEAN SERVICE\nA variety of models that can be used to predict oceanic conditions are being developed at GFDL. The\nsimpler models are capable of predicting relatively few parameters. For example, one-dimensional models\nof the turbulent surface layer of the ocean predict SST and heat content of the upper ocean. More complex\n65","three-dimensional models are being developed to study many phenomena: the time-dependent development\nof Gulf Stream meanders and rings; the generation of the Somali Current after onset of the southwest\nmonsoons; response of coastal zones to atmospheric storms; and development of SST anomalies, such as\nthose observed in the tropical Pacific Ocean during ENSO phenomena.\nAccomplishments FY 92\nA high-resolution, global, coupled ocean-atmosphere model that exhibits realistic ENSO oscillations in a\ndecade-long integration with no significant model drift was developed.\nA new hypothesis was developed to explain the unique character of the Atlantic overturning \"conveyor\nbelt\" circulation. Mechanical forcing by westerly winds over the Southern Oceans may be equally as\nimportant in forcing pole-to-pole overturning as the effect of thermohaline density gradients.\nA retrospective calculation was carried out for a global ocean model using the historical record of\ntemperature over the past century as input. Predicted subsurface temperature changes compare favorably to\nobservations in the North Atlantic.\nPlans FY 93\nThe high-resolution, global, coupled ocean-atmosphere model will be used to study the relationship\nbetween the seasonal cycle and ENSO.\nA 1° latitude by 1° longitude model of the world ocean will be developed to explore the hypothesis\nabout the Atlantic overturning \"conveyor belt\" circulation, which has already been tested in lower\nresolution models.\nThe retrospective ocean climate calculations will be continued in higher resolution models.\n66","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nFORECAST SYSTEMS LABORATORY\nBoulder, Colorado\n(303) 497-6378\nAlexander E. MacDonald, Director\nThe Forecast Systems Laboratory (FSL) is organized to transfer scientific and technological developments\nin atmospheric and oceanic research to the Nation's operational services. It conducts programs to integrate,\nevaluate, and apply developments to information and forecast systems. Its essential functions include the\nfollowing:\nExploratory System Development: Developing and validating information systems to satisfy\nNOAA's operational services.\nResearch Applications: Utilizing advances in understanding atmospheric and oceanic processes to\ndevelop improved data management systems, forecasting systems, and analysis systems for geo-\nphysical data.\nSystem Validation: Testing systems in realistic environments to assess their usefulness in improve-\nment of NOAA's services.\nTechnology Transfer: Facilitating transfer of new techniques and systems to operations, working\ndirectly with users.\nSCIENCE DIVISION\nThe Science Division is home to most of FSL's research on small-scale weather phenomena and short-range\nforecasting. Meteorologists in the division study the structure, evolution, and motion of many different kinds\nof weather systems ranging from synoptic-scale waves to mesoscale convective systems (clusters of\nthunderstorms) to localized windstorms and snowstorms. The division also emphasizes the assimilation of\ndiverse meteorological observations for analyzing current atmospheric conditions and for generating short-\n67","range numerical forecasts. Produced in real time at frequent intervals on national and local scales, these\nanalyses and forecasts are valuable to commercial aviation, local forecasters, and emergency preparedness\nagencies. They have also supported or will support several large meteorological field experiments. The\ndivision promotes the application of artificial intelligence (AI) in decision-making. Finally, division scientists\nhave assembled research-quality data sets for the United States.\nThe Science Division comprises four branches: Analysis and Prediction, Artificial Intelligence, Forecast\nResearch Group, and Weather Analysis and Prediction.\nAccomplishments FY 92\nAnalysis and Prediction Branch\nThe Analysis and Prediction (A&P) Branch concentrates on the Mesoscale Analysis and Prediction System\n(MAPS), which was developed in FSL to provide high-frequency (at least every h) analyses of conventional\nand new data sources over the contiguous United States and short-range (out to 12 h) numerical forecasts in\nsupport of aviation and other mesoscale forecast users. MAPS was transferred to the National Meteorological\nCenter (NMC), and is being tested as the Rapid Update Cycle (RUC). It relies heavily on asynoptic data\nfrom commercial aircraft and wind profilers, and also incorporates data from rawinsondes, surface reporting\nstations, and buoys.\nSeveral improvements were made to MAPS during the last year. Formulations prescribing fluxes of heat\nand moisture from the surface to the atmosphere were included, along with a realistic surface energy budget\nincluding the effects of interactive clouds diagnosed from model-forecast relative humidity. As expected,\nthis change has improved forecasts of surface temperature and winds. A version of the MAPS model using\na modified vertical coordinate was developed; regular testing has shown a reduction of noise in the model.\nFinally, a dynamic initialization procedure was tested that gives further noise reduction, especially during the\nfirst few hours of the model forecast.\nThe RUC began running a continuous 3-h cycle at NMC in June 1992. Grids from the RUC are now being\nevaluated at FSL and NMC.\nA study of the effect of wind profiler data on short-range forecasts was completed. Running parallel cycles\nof MAPS with and without profiler data showed that the profiler data had a relatively small but consistently\npositive statistical impact on forecasts of winds and heights. The effect was more pronounced when active\nweather systems passed through the Wind Profiler Demonstration Network (WPDN).\nTechniques to diagnose aviation-impact variables (AIVs; precipitation type, cloud layers, visibility,\nceiling) were developed for use with MAPS analyses and forecasts.\nFurther testing of a 1-h MAPS cycle revealed a gradual build-up of noise; this shows poorer results than\nfrom a 3-h cycle for the same periods. The new dynamic initialization scheme is expected to alleviate\nthis problem.\nArtificial Intelligence\nThe AI Project develops, investigates, and tests AI applications in the environmental sciences. AI is a\nbranch of computer science that focuses on using heuristic knowledge to solve problems; this technology is\ncomplementary to gridded numerical models. For example, numerical models generate forecasts by solving\nequations at an array of grid points, whereas AI systems manipulate concepts such as \"updraft,\" \"cold front,\"\n68","Forecast Systems Laboratory\nand \"supercell\" generate forecasts. Thus, muchlike humans, AI systemsare designed to \"think\" about\nconcepts.\nWe analyzed data from Shootout-91, a comparison of systems that forecast severe weather. The\nexperiment, built on a similar exercise held in 1989, was a joint venture of FSL, National Severe Storms\nLaboratory (NSSL), National Environmental Satellite, Data, and Information Service (NESDIS), and the\nNational Weather Service (NWS). Canada's Atmospheric Environment Service (AES) and the U.S. Army\nAtmospheric Science Laboratory also participated. Three artificial intelligence systems, a system based on\na numerical data-assimilation model, and teams of human forecasters made daily forecasts of severe and\nsignificant weather for Oklahoma and northeastern Colorado.\nShootout-91 results were varied. For example, Oklahoma forecaster teams generally did better than either\nBoulder forecasters (who worked individually) or the expert systems in forecasting spring weather in\nOklahoma. We learned that the differences in skill among humans, all the systems, and persistence were not\nsignificant in Colorado. Skill was substantially decreased for Colorado when compared to Oklahoma. In\nfact, the best forecasts for Colorado had lower skill than the worst forecasts for Oklahoma. For forecasts of\nsignificant weather in Colorado, only persistence had a skill significantly better than random forecasts.\nIn cooperation with scientists at the State University of New York at Albany, the U.S. Air Force Phillips\nLaboratory, and the University Corporation for Atmospheric Research's (UCAR) Cooperative Program for\nOperational Meteorology, Education, and Training (COMET), an analysis was completed of the Weather\nInformation and Skill Experiment (WISE-II). WISE, a series of studies on the cognitive aspects of short-term\nweather forecasting, tested the skill of weather forecasters under a variety of information loads, from very\nlimited information (sketches of radar reflectivity) to full information (a computer workstation with full\nanimation). Results indicate that, although forecasters did better when presented with full information,\nindividual differences between forecasters exceeded skill differences depending on level of information,\nsuggesting that appropriate forecaster training is necessary if the full capability of new meteorological data\nsources is to be realized.\nThe Metalog program, a system to maintain and manage scientists' comments about their data, was applied\nto the Comprehensive Ocean-Atmosphere Data Set (COADS), and was sent to more than 50 environmental\nscientists worldwide. Descriptive data (metadata) about COADS were gathered from published sources,\nWorld Meteorological Organization (WMO) data tapes and interviews with experts. Metalog is also being\nused to document paleoclimatology data sets at the National Geophysical Data Center (NGDC).\nForecast Research Group\nThe Forecast Research Group (FRG) is contributing to the modernization of the Nation's weather service\noffices in six areas: quantitative data integration, modeling, quality control, visualization, technology transfer,\nand system evaluation.\nFRG's major focus is the research and development of the Local Analysis and Prediction System (LAPS).\nThe goal of LAPS is to provide real-time, three-dimensional, local-scale analyses and short-range (0-12h)\nprediction of the atmosphere for a typical NWS Forecast Office (NWSFO) or military weather unit area of\nresponsibility. The system design fully incorporates emerging observation technologies (e.g., Doppler radar,\nwind profiler, automated surface observation, digital satellite, and aircraft observation) and advancements in\ndesktop super-minicomputers. Since the local weather offices will be the only locations to receive\nfull-volume Doppler radar data together with all other data sources, LAPS is designed to perform in this\nsetting. Now that the prototype analysis portion of LAPS has been implemented at the NWSFO in Denver,\nColorado, LAPS is shifting to two particular areas: quality control, verification, and improvement of analyses;\nand short-range (0-12 h) prediction. We cooperate with the FSL Systems Development Division to exploit\nthe visualization capabilities of the super-minicomputers, especially since LAPS must be portable. To ensure\n69","that forecast problems are optimally addressed during development, FRG scientists periodically work forecast\nshifts at the Denver NWSFO.\nThe LAPS suite of gridded analyses was improved and continues to be available on FSL's Denver AWIPS\nRisk Reduction and Requirements Evaluation (DARE-II) workstation. The complete surface analysis\npackage is available to the Denver NWSFO. As a result of the excellent feedback from Denver forecasters,\ntwo more surface products were added. The quality control of LAPS analyses was improved by initiating\nobjective quality control schemes, and some of the prototype schemes were implemented.\nThe use of LAPS and participation of FRG meteorologists were important elements during the Stormscale\nOperational and Research Meteorology Fronts Experiment Systems Test (STORM-FEST), conducted from\n1 February through 15 March 1992. STORM-FEST gathered data to investigate and better understand the\ngrowth and patterns of fronts and precipitation of winter weather. The full suite of LAPS products were\ngenerated for the STORM-FEST domain, demonstrating the portability of LAPS.\nIn cooperation with the Massachusetts Institute of Technology (MIT), FRG implemented LAPS on a\nUNIX-based platform, called Terminal LAPS (T-LAPS). T-LAPS, which also demonstrated the portability\nof LAPS, uses a nested grid system to provide enhanced wind analyses for a typical airport control tower\nregion of responsibility. T-LAPS was operational during the summer of 1992; this was the first time that\nradar data from the Weather Surveillance Radar (WSR-88D) and the Federal Aviation Administration (FAA)\nterminal Doppler weather radar were combined and used outside those systems.\nLAPS analyses were used to initialize the Colorado State University Regional Atmospheric Modeling\nSystem (CSU-RAMS) for several winter and summer cases. The ability to run the model on Stardent\ncomputers with excellent short-range model forecasts demonstrates our successful prediction of mesoscale\nfeatures in the operational setting. Three-dimensional visualization of LAPS analyses and RAMS forecasts\nusing the Advanced Visualization System on Stardent computers has demonstrated the immense potential\nof\nsuper-minicomputers for running numerical models and viewing their output.\nFRG scientists are helping to build a system based on LAPS for the FAA called the Aviation Gridded\nForecasts System (AGFS).\nFRG evaluated Department of Defense (DOD) systems such as the MARK-IVB Satellite Data System\nand associated software. FRG also developed a WSR-88D data recovery system for testing, evaluation, and\ntuning of NEXRAD algorithms.\nWeather Analysis and Prediction Branch\nThe Weather Analysis and Prediction (WAP) Branch performs diagnostic studies of weather-related\nphenomena, including winter snowstorms, downslope windstorms, and mesoscale convective systems.\nThese studies often result in products of value to forecasters, and WAP assists in their transfer (and follow-up)\nto NWS. WAP also assembles research-quality data sets to support its activities and makes these data sets\navailable to the NOAA laboratories and NWS research groups.\nSeveral improvements to a high-wind forecasting technique were made this year. A new feature that\naccounts for the presence of cold air against the Front Range is now included in the technique. An expert\nsystem for forecasting high winds at Fort Collins and Boulder has been written for PCs. The software\ncomprises teaching and operational modules. An on-line tutorial, capable of displaying graphical examples\nof typical synoptic situations for several windstorm conditions, accompanies major decision points in the\ntechnique. The operational system is interactive, requiring forecasters to enter their best information on\nseveral factors, including winds forecast at locations upstream in the flow from Boulder. Typically, grid-point\ndata from NMC's Nested Grid Model (NGM) are used for this variable. This past year we made this step\nmore efficient by automatically transmitting data from the required grid points to the Denver NWSFO, thus\nsaving forecasters time in the previously tedious and somewhat inaccurate task of reading the information\n70","Forecast Systems Laboratory\nfrom graphical screens. A developmental version of the expert system currently runs automatically at FSL\non the VAX cluster for use by windstorm researchers.\nWAP continued to construct science-quality data sets of radiosonde data for North America, hourly\nprecipitation data (HPD) for the United States, and voice pilot reports (PIREPS) over North America.\nVMS-based (Virtual Memory Systems) access and display routines for the 40-year rawinsonde/radiosonde\nobservations data set were modified for use with UNIX and DOS operating systems, under collaboration with\nthe National Climatic Data Center (NCDC). Documentation of the quality control checks performed at FSL\non these data and a compilation of metadata on instrumentation information and station history are now in\nprint. Several display routines for use and quality control of the HPD were developed. These routines plot\nstation identification numbers and precipitation amounts for user-specified states or geographic locations at\nthe user-indicated time periods. Under collaboration with scientists from the National Center for Atmos-\npheric Research (NCAR) funded by NOAA's Office of Global Programs, portions of this data set are being\nused to validate precipitation output by a climate model and to derive stochastic models of daily and monthly\nprecipitation for diverse locations in the United States. Accessing and reformatting routines for PIREPS data\nwere completed. Data transmitted in real time over operational circuits are automatically quality controlled\n(e.g., checked for obvious errors in the data fields, and duplicates removed) and written into FSL's on-line\nscience-quality data set. Special PIREPS data sets compiled during STORM-FEST by commercial airlines\nunderwent similar checks and were added to the data set.\nWAP began studies to improve the forecasting of clear-air turbulence with the help of NMC's next-\ngeneration operational weather model, the Eta model. A surprising finding was the inability of the 30-km\nversion of the model to produce significant amounts of turbulent kinetic energy (TKE) above the boundary\nlayer. NMC is working to remedy this shortcoming. We began to study possible connections between\nobservations of clear-air turbulence in the second-moment data of the wind profiler, which indicate the spread\nin velocity values within the volume of air observed by the radar. The spread in velocity values tends to\nincrease as the median values of reported intensity of turbulence increase.\nThe FSL Dissemination Project\nThe FSL Dissemination Project is managed by FSL's Senior Scientist in the office of the Director. The\nproject focuses on an experimental research system to conduct experiments to see how advanced meteoro-\nlogical information can be used by local governments. This project is coordinated with the University of\nColorado at Boulder (CU-Boulder), and the City and County of Boulder.\nMost research and development aspects of the NWS modernization are mature. For example, advanced\nobservational systems such as NEXRAD Doppler radars and Automated Surface Observing System (ASOS)\nare being deployed across the United States. Modern weather information display systems and advanced\nmeteorological forecast models are nearing development completion, and installation in NWS operations will\nbe scheduled.\nThe scope of the Dissemination Project involves several questions: (1) How should the new weather\ninformation be formatted and sent to local emergency management organizations? (2) What data within the\nlocal government should be combined with the new weather data? (3) What technology, if any, is required\nto assist local governments in effectively using the new weather information? (4) Which emergency\nmanagement functions are effectively assisted by these new data? (5) Can useful information be delivered to\nlocal government at a reasonable cost?\nTwo experimental local weather decision support systems were designed and built in FSL. One system\nspecializes in flash flood monitoring and prediction, and the other provides general weather information in\na form useful to local government personnel such as emergency management officials. These two systems\nwere later used by the City of Boulder emergency management officals, operational and research meteorolo-\n71","gists, and NWS personnel. The capabilities of these systems were refined in response to the critical reviews\nof these users.\nPlans FY 93\nThe A&P Branch will implement the new hybrid vertical coordinate, tested in FY 92, in all components\nof MAPS (observation and NGM ingest, quality control, analysis, and forecast model). A dynamic initiali-\nzation procedure will be implemented operationally in the MAPS forecast model, resulting in less noisy fields\nduring the first few hours of forecasts.\nAll MAPS software will be converted to a standard version that works on all computers on which MAPS\ncurrently runs [National Airspace System (NAS), VAX, Cray, IBM workstations]. The software to be\nconverted will include the upper-air analysis/forecast cycle as well as the hourly surface analysis cycle. The\nnew standard version will be tested and implemented at FSL and NMC.\nFurther testing of a 1-h cycle will be carried out. The new tests will include a dynamic initialization\nprocedure at the beginning of each model forecast. Initial tests of a 30-km version of the MAPS model will\nbe conducted, and this version will have 30 to 40 vertical levels and will use the new hybrid vertical coordinate\nwith nonintersecting levels.\nTechniques for diagnosis of AIVs from MAPS grids will be improved, in support of the AGFS. Turbulence\nand icing products will be developed during FY 93.\nThe AI Branch will expand the use of Metalog in support of other NOAA data bases such as the Global\nTemperature and Salinity Pilot Project data set at the National Ocean Data Center (NODC), and the Active\nArchive project at the NESDIS Office of Satellite Data Processing and Distribution. We will also gather and\nrespond to feedback from users of the current version of Metalog, and publish a revised and expanded version\nof COADS metadata that is responsive to user feedback. The UNIX operating system will be ported to run\nunder the X-Window environment.\nThe AI Branch will develop the NOAA Earth Watch Service (NEWS), a service that will use electronic\nnetworking and multimedia data presentation to provide NOAA information about earth system variations\nto policy makers, scientists, and the general public. In conjunction to this project, we will begin to prepare\nthe third edition of the NOAA Environmental Digest, a compendium of information about past trends in earth\nsystem variables.\nWe will explore and implement AI techniques to disseminate NOAA weather information to local\ngovernments for use by, for example, forest fire fighters, in a form that is relevant and easy to interpret.\nThe FRG will develop quality control methods to verify and improve existing LAPS analyses. Acquisition\nof an IBM-RISC computer workstation will allow daily short-range weather prediction using the CSU-\nRAMS model initialized with LAPS, and the development of a full four-dimensional data assimilation\n(4DDA) scheme. RAMS will be run in parallel versions to speed run times and provide real-time\nforecast capability.\nA forecast exercise, Zcast-93, will run during the summer 1993 to test the 4DDA scheme and to measure\nthe progress of LAPS against the baseline performance established during Zcast-91. LAPS short-range\nprediction products will be generated for critical examination during the FSL daily weather briefings.\nFRG will increase interaction with local and national groups to explore the use of LAPS in high-resolution\nforecasting for fire and flood applications.\nThe WAP Branch will assess factors affecting the Eta model's production of TKE above the boundary\nlayer. Among the factors to be investigated are the role of the vertical and horizontal resolution of the model\nand the testing of alternative formulations of the TKE parameterization. Tests will be made in conjunction\nwith other models, such as CSU-RAMS, and for specific sources of clear-air turbulence, such as gravity\nwaves. In collaboration with NMC, we will modify the Eta model's TKE parameterization.\n72","Forecast Systems Laboratory\nIncorporation of the calculation of additional AIVs in the Eta model will continue. We will also collaborate\nwith NMC to improve AIVs currently produced by the model, for example, surface temperature. We will\nmake performance assessments of Eta model AIVs for selected cases, including cases from STORM-FEST.\nWAP will sharpen relationships between wind profiler data and pilot reports of turbulence. Sources of\nerror in each data set will be investigated. Nonturbulent sources of signal variation such as precipitation in\nthe sample volume will be identified and removed. We plan to make PIREPS data less subjective by\nstratifying, for instance, aircraft type and size. Wind profiler second-moment data will be compared to gust\nprobe data from a research aircraft.\nVersion 1 of the science-quality, 40-year raob data set for North America will be mastered on optical disk.\nAccess software, station history information, and rudimentary displays for data selection will be included\nwith the data. The project is a cooperative effort between FSL and NCDC. The CD-ROM data sets will be\navailable through NCDC.\nThe latest version of the expert system to forecast high winds will be installed at the Denver NWSFO.\nNWS personnel will be informed of improvements to the program and trained in the use of a new feature that\naccounts for the presence of cold air against the Front Range.\nStaff in the office of the FSL Senior Scientist will install the first version of the general user system in the\nEmergency Operation Center of the City and County of Boulder. The information displayed on the system\nwill be studied and assessed for its potential use (e.g., to predict flash floods and wild fires). The studies will\nbe performed by researchers at CU-Boulder and City and County users.\nFACILITY DIVISION\nThe Facility Division (FD) operates the FSL computer facility to acquire, process, store, and make available\nto FSL users a wide variety of meteorological data for research and systems development. The computer\nfacility provides capabilities for testing and evaluating advanced weather observation, analysis, and infor-\nmation delivery systems. FD staff operates, maintains, modifies, and upgrades all FSL computers and\nassociated networks.\nAccomplishments FY 92\nComputer Facility\nAs part of converting the current VAX/VMS-based computer facility to a distributed open-systems\nenvironment, FD completed the first phase of the Portable Operating System Interface for Computer\nEnvironments (POSIX) Data System (PDS). The PDS collects, processes, stores, reformats, and distributes\nFSL data using WMO standard formats and protocols.\nTo provide an open-systems distributed computing environment for FSL users, we configured and installed\n24 Sun RISC-UNIX workstations. Eight work group subnets with UNIX server gateways were implemented\nto facilitate laboratory-wide interconnectivity and to provide effective computing capabilities for FSL\ndivisions and projects.\nTo improve FSL data communications throughput, FD installed a second, alternate T1 (1.5 Mbps)\nconnection to the NSFNET/Internet backbone through NCAR's facility. We reconfigured and implemented\ntwo Internet gateways for increased network reliability and availability. We substantially improved the\noverall laboratory computer linkage by attaching 12 additional PCs and Macintoshes to the FSL network.\n73","Data Acquisition\nWe developed data-ingest interfaces for NOWrad (WSI Inc. trademark) national radar data and national\nlightning data and made these data available to FSL users and projects. FD completed development of the\nmultiradar WSR-88D Doppler radar product interface and ASOS data-acquisition subsystems for the Norman\nPre-AWIPS (Advanced Weather Interactive Processing System).\nWe substantially increased the number of automated aircraft observations by upgrading the FD pilot report\ningest subsystem to acquire, decode, and store airline satellite-relayed reports and position reports.\nResearch Support\nFD continued to provide both real-time and retrospective meteorological data and products (including FSL\nMesonet, Doppler radar, upper-air soundings, surface aviation observations, profiler, satellite imagery and\nsoundings, MAPS and LAPS grids) to researchers at NCAR, National Aeronautics and Space Administration\n(NASA) Ames, CSU, MIT Lincoln Laboratory, Climate Monitoring and Diagnostics Laboratory (CMDL),\nWave Propagation Laboratory (WPL), and NSSL.\nWe supported, with real-time data and products, NOAA and other agency experiments including STORM-\nFEST, Winter Icing and Storms Project (WISP), and First International Satellite Cloud Climatology Project\n(ISCCP) Regional Experiment (FIRE).\nFD advised many users (within NOAA and other agencies) of the FSL computer facility, data, products,\nand communications capabilities.\nProject Support\nWe continued to provide the Denver NWSFO pre-prototype AWIPS with real-time meteorological data\nand products. We worked with NESDIS and NWS to place into operation the high-speed Information Stream\nProject for AWIPS and NOAAPORT (ISPAN) data links.\nFD developed and started testing a PDS-based distribution system to provide data and products to the\nAGFS functional prototype workstation. We initiated the distribution of national lightning, radar, upper-air,\nand surface aviation observations data to the FAA through the Aviation Division's Advanced Traffic\nManagement System (ATMS).\nWe also provided extensive technical help and advice to Taiwan Central Weather Bureau (CWB) staff to\nconfigure, tune, and place in operation the CWB central computing facility in support of the Taiwan Area\nMesoscale Experiment (TAMEX).\nPlans FY 93\nFD will continue the transition of the FSL computer facility toward a fully open-systems computing\nenvironment. We will initiate a transfer of all product generation, storage, and data and product distribution\nto the PDS using WMO standard data formats. In addition to implementing an expected large number of\nadditional RISC-UNIX scientific workstations and servers, FD will integrate the new massively parallel\nprocessor into the facility.\nNew data-acquisition interface developments will include the next generation of Geostationary Opera-\ntional Environmental Satellites (GOES-NEXT), wide-band WSR-88D Doppler radar, and an upgraded\nFSL Mesonet.\n74","Forecast Systems Laboratory\nAs ISPAN begins to provide operational data to the Denver NWSFO, FD will continue transmitting\nadvanced meteorological products to Denver and will serve as backup for ISPAN. FD will initiate the\ntransmission of data and products to AGFS functional prototype workstations at the FAA Air Route Traffic\nControl Center (ARTCC) in Longmont, Colorado, and NCAR Research Applications Program.\nDEMONSTRATION DIVISION\nThe Demonstration Division (DD) is responsible for transferring technology and expertise from the\nresearch and development arena into the operations domain, in three different areas. The most important area\nis our expertise, or experience, gained in the operation, maintenance, and assessment of the WPDN. This is\na network of specialized radars, capable of measuring vertical profiles of wind, that are located mostly in the\ncentral United States. Second, the DD was selected to be the site operator for the Department of Energy's\nSouthern Great Plains Cloud and Radiation Testbed (CART) site in northern Oklahoma, in the center of our\nWPDN. Another major responsibility is to transfer our Configuration Management Integrated Support Tool\n(CMIST) technology (which was developed using NWS guidelines to meet the special needs of systems such\nas the WPDN) to other government programs and private industry.\nAccomplishments FY 92\nWe accepted all 30 wind profilers, along with their required communication links, that were installed by\ncontractors. Data from 29 production wind profilers and one prototype are routinely being sent to the NWS\nTelecommunications Gateway for distribution to forecast offices, the private meteorological community\nthrough the NWS Family of Services, Unidata for distribution to university and other research users, and\nNCDC for permanent archiving. transition plan for the WPDN from a demonstration network to a network\nmanaged by NWS was developed, at the request of the Department of Commerce, and submitted for approval.\nThe DD provided data, available at a 91% rate during the 6-week period, to STORM-FEST. Profiler data\nreliability was increased by installing protective limiters on all receivers and by upgrading the lightning\nprotection at all central United States sites. We improved the capability of the Homer, Alaska, profiler to\nperform in the presence of sea clutter.\nOperations for CART are under way, and two DD contractors are permanently on site performing\noperations activities.\nPrototype versions of the CMIST software were demonstrated at NWS Headquarters and at the NEXRAD\nOperational Support Facility. Discussions are progressing toward a Cooperative Research and Development\nAgreement for commercializing CMIST software.\nPlans FY 93\nThe DD will continue to operate and maintain the WPDN and supply data for operations, research, and\nassessment. We will improve profiler reliability by acquiring new beam steering units and receivers and\ninstalling them throughout the network. We will also improve profiler data quality in the lowest 3 km. We\nwill continue to diagnose chronic problem areas with the profilers, such as the transmitter modules and\ncombiners, and promptly correct them.\n75","A demonstration version of CMIST will be developed to determine the marketability of the technology.\nWe will continue ongoing configuration management for the WPDN using the internally developed CMIST\nsoftware. We will install, operate, and assess Radio-Acoustic Sounding System (RASS) temperature profilers\nat five sites in the WPDN.\nWe will continue management of site operation activities at the CART site.\nDD will initiate two new plans. One is a program with the Taiwan Civil Aeronautics Administration and\nCWB to aid them in developing a profiler network there. We will also assist NWS in planning a network of\nprofilers in critical regions for storm genesis.\nAVIATION DIVISION\nThe Aviation Division (AD) works with the FAA and NWS on developing the AGFS, aviation forecast\nverification, advanced computing techniques, and aviation weather products for the FAA's ATMS.\nAccomplishments FY 92\nAviation Gridded Forecast System\nThe AGFS is an interactive information-processing display and a communications system that will generate\nhigh-resolution gridded analyses and forecasts of state-of-the-atmosphere variables (SAVs) and AIVs. AIVs\nare variables such as icing, ceiling height, and turbulence. Those grids will constitute the meteorological data\nrequired to tailor decision-making products for aviation users and support automation of the FAA's Air Traffic\nControl (ATC) system.\nWe developed a functional prototype of the AGFS workstation and arranged to implement that workstation\nat the Denver ARTCC Center Weather Service Unit (CWSU). The purpose of implementing the workstation\nhere is to define required data and the role that CWSU forecasters will play in the AGFS era. Two of our\ndevelopment meteorologists are becoming proficient at the CWSU to support the risk reduction effort.\nAD coordinated closely with the NWS to arrange for implementing AGFS FP workstations at the National\nAviation Weather Advisory Unit (NAWAU), the Denver WSFO, and at the Central Flow Weather Service\nUnit (CFWSU), located in Washington, D.C. (NAWAU prepares regional aviation forecasts, and the CFWSU\nsupports air traffic management.) The workstations will be significantly important to the NWS Experimental\nForecast Facilities (EFFs).\nWe also worked closely with the other participants in the FAA's Aviation Weather Program to ensure that\nthe AGFS will interface effectively with current developments.\nAviation Forecast Verification Program\nA verification program was created to assist in deriving AIVs from the output of meteorological models.\nThe objective of the program is to provide atmospheric modelers with statistical measures of the accuracy of\nforecasts to develop and improve aviation forecasts. We completed a baseline evaluation of MAPS, LAPS,\nthe CSU-RAMS model, and the Eta model.\nWe began plans to evaluate the functional prototype when it is installed at the Longmont ARTCC.\n76","Forecast Systems Laboratory\nAdvanced Computing\nAD created an Advanced Computing Group (ACG) to develop parallel processing techniques to efficiently\nrun newer and better numerical weather prediction (NWP) models.\nWe provided support to the FSL director's office in forming the Front-Range Consortium (FRC). Members\nof the FRC include FSL, NCAR, and CU-Boulder. FRC's proposal to the Defense Advanced Research\nProjects Agency (DARPA) was approved for massively parallel processing (MPP) hardware and a high-speed\ncommunication network for its members. The first FRC MPP was installed at CU-Boulder and is being used\nby FSL to test concepts associated with parallelizing NWP models. FSL signed an agreement with FRC to\nhave the next MPP installed here; procurement is in process.\nWe developed a benchmark suite for evaluating the performance of MPPs, and then proceeded to evaluate\nthe available MPPs. We will continue to evaluate MPPs as they enter the market. We also developed a\nportable parallel processing support library specification to ensure that our large investment in parallel\nsoftware will be portable to, and efficiently run on, various types of MPPs. Another advantage of the portable\nlibrary is to be able to run parallelized models on workstation clusters.\nACG acquired a network of UNIX-based servers and scientific workstations to support the AGFS, parallel\nmodeling development, and model verification. This new equipment significantly moves FSL toward an\nopen-systems approach and away from a vendor-specific computer orientation.\nAdvanced Traffic Management System\nThe ATMS Branch conducts research and development to validate the use of advanced weather information\nfor the FAA air traffic management. Emphasis is placed on the development of real-time meteorological data\nsets that are integrated into the FAA's aircraft situation display (ASD) for operational testing. To develop\nand distribute weather products for FAA air traffic, we created a functional environment that includes an ASD\nin which the ATMS weather products can be overlain on real-time FAA air traffic data sets. This enables FSL\nresearchers to observe the impact of ATMS weather products on flight operations.\nATMS weather products are rapidly prototyped and tested on the FSL VAX cluster. These products are\nthen moved to an ATMS product generation and distribution system (under configuration management) for\ndissemination to the John Volpe National Transportation Systems Center (JVNTSC) in Cambridge, Massa-\nchusetts, via satellite. JVNTSC then disseminates the weather data to the FAA's air traffic management\nfacilities nationwide.\nPlans FY 93\nAD will implement AGFS functional prototype workstations at the NWS EFFs to conduct risk reduction\nfor the operational AGFS. We will prepare to conduct a demonstration in 1994 of capabilities for the initial\noperational version of the AGFS. We will work closely with the NWS to incorporate the AGFS into the NWS\nstrategic plans.\nThe Verification Program will conduct a second evaluation of model AIVs, including additional parameters\nsuch as icing and turbulence, and begin evaluation of the forecast program. AD will work with NMC to\ndevelop a parallel version of the Eta model using our portable parallel processing support library. We plan\nto collaborate with CSU to develop a parallel version of the RAMS model.\nATMS will conduct a validation exercise to determine the utility of the current ATMS weather products\nfor air traffic management.\n77","We will develop, test and implement several products, for example, a national Convective Airspace\nGuidance product that uses NOWrad radar, lightning, and MAPS wind data to forecast the propagation of\nconvective cells within the NAS.\nSYSTEM DEVELOPMENT DIVISION\nAccomplishments FY 92\nSDD maintained the pre-AWIPS functional prototype systems at Norman, Oklahoma, and at Denver. The\nmaintenance included upgrades to the national data feed (ISPAN) and WSR-88D radar interfaces, enhance-\nments of workstation display functions, and upgrade of the data server computer.\nThe PC workstation software was ported to a new UNIX operating system. New functions were added\nthat included text display, satellite remapping, manual graphic generation, and hard copy production.\nWe started a new project to develop an advanced meteorological workstation that would be portable across\nvarious hardware platforms. The workstation will use a broad array of industry standards. SDD completed\nthe requirement analysis, initial design, and significant prototyping of the user interface and display functions.\nSDD developed additional modules for the AVS on the Stardent computer in support of research activities\nwithin FSL.\nPlans FY 93\nSDD will continue to support the pre-AWIPS functional prototype workstations at Norman and Denver.\nPlanned enhancements include expansion of the pre-AWIPS workstation system into the EFF at Norman,\nand a link from the Norman NWSFO to the Tulsa River Forecast Center in Tulsa, Oklahoma.\nThe PC workstation will be installed in the Longmont ARTCC to demonstrate and test the aviation project\nAGFS. The PC workstation configuration will consist of a UNIX network file server and a powerful PC\ncomputer. A new release of the PC workstation software will be prepared for the next COMET course,\nscheduled for spring 1993.\nThe first release of the FX workstation software is scheduled to be ready by the end of FY 93. The FX\nworkstation will replace the PC workstation installed at the Longmont ARTCC. We will continue expansion\nof the three-dimensional visualization capabilities, and have long-term plans to integrate a three-dimensional\nfnction into the FX workstation.\nSDD will continue providing technical consultation and guidance to the U.S. Air Force Defense Meteoro-\nlogical Satellite Program (DMSP) and Taiwan's CWB.\n78","Forecast Systems Laboratory\nMODERNIZATION DIVISION\nAccomplishments FY 92\nRisk Reduction Branch\nThe Risk Reduction (RR) Branch accomplished a major milestone this year: an interface to the first\nWSR-88D Doppler radar was installed at Norman. This interface integrates local radar data into the\npre-AWIPS workstations. It also provides all the control functions needed to interact with the WSR-88D\nRadar Product Generator. A second WSR-88D radar was connected to this interface during the latter part of\nFY 92, providing radar coverage over the entire area of responsibility. This dual-radar capability has been a\nsignificant benefit to the Norman NWSFO in active weather. Additional enhancements were made on the\nwarning generation capabilities that allowed the Norman NWSFO to begin using pre-AWIPS to issue severe\nweather warnings.\nMany upgrades were accomplished on data acquisition systems. The ISPAN central feed of satellite data\nwas completed with the addition of large-scale satellite imagery. Refinements and improvements were made\nto the ISPAN circuit, resulting in a more reliable delivery of data. ISPAN data feeds were installed in Denver.\nAn interface to the ASOS system was developed and tested.\nA significant upgrade of the system hardware greatly improved the speed of data storage and retrieval and\nmore than doubled the speed at which products are generated. Software upgrades through the year added\nnew capabilities and improved the overall operation of the system. A new text workstation was developed\nbased on industry standard X-Window.\nWe supported the Norman Evaluation Committees, which evaluate user experiences at Norman and their\nimpact on the NWS modernization. We prepared reports on training, product usage, and the enhanced\nterminal forecast experiment conducted at Denver.\nEnhanced Forecaster Tools Branch\nA major project of the Enhanced Forecaster Tools (EFT) Branch is to develop an AWIPS Forecast\nPreparation System (AFPS), formerly known as Gridded Representation of Analyses and Forecasts (GRAF).\nThe goal of AFPS is to develop a graphical forecasting system for the NWS with which forecasters will\nvisualize and edit the weather in their area of responsibility. AFPS will be deployed at NWSFOs in the\nlate 1990s.\nThe foundation has been laid for developing the AFPS. For example, the Modernization Division (MD)\nprocured a development computer system, a workstation and a server for each staff member. MD and FD\ntrained all users in UNIX, C, and C++ languages.\nWe developed some early prototypes of the graphical editing tools and data base, and our design of the\nuser interface and graphical editors is progressing.\nAdvanced Development Facility Branch\nThe Advanced Development Facility (ADF) Branch was established to provide technical guidance to\nNOAA regarding the definition, enhancement, and evolution of the AWIPS-90 system, the centerpiece of\nthe NWS modernization program. This initially involved assisting NWS in defining requirements for the\nAWIPS-90 system.\n79","ADF helped the AWIPS-90 program office evaluate proposals in preparation for the AWIPS contract\naward, in November 1992. ADF completed the procurement, installation, and configuration of the MD\ncomputing system, and it now administers and provides technical assistance to software developers. It\nsupports software development in FORTRAN, C and C++ languages and a variety of software standards\nand libraries.\nPlans FY 93\nThe RR Branch will install the WSR-88D interface in Denver and will develop an area-wide hydrologic\nforecast system and a case review feature for the Norman facility. We will develop a case review capability\nfor the Norman system. ASOS will be installed and its interface will be further developed. Further, we will\ndevelop a monitoring capability that allows users to specify thresholds and data types to be monitored.\nThe EFT Branch will finalize the AFPS development plan. An early prototype, built according to the AFPS\ndesign architecture, will demonstrated at the 73rd Annual American Meteorological Society Meeting.\nEFT will prepare an integrated prototype comprising a data base, graphical editors, and user interface, and\ncompletion is expected near the end of the fiscal year.\nThe Government Development Platform (AWIPS hardware and commercial off-the-shelf software) will\nbe delivered to FSL. Staff will become familiar with the system, and begin to integrate it and the existing\ncomputer system into an enhanced development environment.\nThe ADF Branch is changing its focus in preparation for the AWIPS contract award. We will be involved\nin contractor design reviews, and will work with the AWIPS program office to provide technical guidance to\nthe AWIPS contractor. We will ensure that the AWIPS implementation proceeds smoothly, and starts with a\ncorrect understanding of system requirements, particularly with regard to weather field office operations.\nADF will increasingly emphasize support of AWIPS enhancement activities throughout the fiscal year. A\nrecent rebaselining of the AWIPS program calls for a significant portion of AWIPS software to be supplied\nby software development groups within the NWS and NOAA, MD will work with the NWS to help\ndevelopers understand the AWIPS system design, and to smoothly integrate new capabilities into AWIPS.\nWe will also collaborate with the NWS to establish standards and guidelines applicable to all software being\ndeveloped for integration into AWIPS. ADF will perform the integration and configuration, and develop\nplans for providing software configuration control within the local AWIPS environment.\nWith the implementation phase of AWIPS well under way toward the end of FY 93, ADF will devote more\nattention to long-range tasks, which center on defining an evolutionary path for AWIPS SO that it continues\nto keep pace with technological developments.\n80","3\nOffice of the\nDirector\nJoint\nInstitutes\nSEL\nAOML\nGLERL\nFSL\nWPL\nARL\nAL\nPMEL\nGFDL\nNSSL\nCMDL\nNATIONAL SEVERE STORMS LABORATORY\nNorman, Oklahoma\n(405) 366-0427\nRobert Maddox, Director\nThe National Severe Storms Laboratory (NSSL) develops scientific bases for improved weather forecast-\ning through studies of mesoscale weather processes and numerical and conceptual modeling of storm\nphenomena. Technological developments, scientific advances, and new requirements are reflected in\nchanging approaches to achieving the goals of accurate, timely forecasts and warnings. Recent studies have\ndrawn heavily on observations from airborne and ground-based Doppler radar, instrumented mobile labora-\ntories, lightning-mapping systems, wind profilers, and satellites.\nMESOSCALE RESEARCH DIVISION\nAccomplishments FY 92\nResearch within the Mesoscale Research Division of NSSL continued to focus primarily on analyzing and\ninterpreting observational data of mesoscale convective systems (MCSs), drylines, and related phenomena.\nAnalysis of data sets collected during the Preliminary Regional Experiment for Stormscale Operational and\nResearch Meteorology-Central (PRE-STORM), the Cooperative Oklahoma P-3 Studies-1989 (COPS-89),\nthe Southwest Area Monsoon Project (SWAMP), and the Cooperative Oklahoma Profiler Studies-1991\n(COPS-91) continues. New efforts have been started to study the structure and evolution of the dryline using\nthe Colorado State University Regional Atmospheric Modeling System (CSU-RAMS) mesoscale numerical\nmodel. A major new planning effort is also under way as part of the division's contribution to the Tropical\nOcean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) research\nprogram. In TOGA COARE, division scientists will participate as airborne mission scientists and principal\ninvestigators to document momentum transports in tropical oceanic convection.\n81","MCS Research\nEvaporation rates retrieved from dual-Doppler data at different locations in the stratiform region of a squall\nline were compared. The evaporation rate was highest toward the rear of the main stratiform region rainband,\nwhere air in the rear inflow first encounters relatively heavy precipitation. In the zone of lighter precipitation\nbetween the stratiform rainband and the convective line, the evaporation rate was lower than anywhere else\nin the stratiform region because the air was by then moistened and the precipitation rate was low. This result\ndisproves earlier speculations that the zone of light precipitation between the convective line and the stratiform\nregion is a result of rampant evaporation.\nAirborne Doppler radar data collected by the NOAA P-3 aircraft and balloon-borne electric field meter\ndata from several MCSs during spring 1991 were gathered to document the precipitation, kinematic, and\nelectrical structure of these events. In a somewhat surprising result, the vertical profile of in situ charge from\n\"bow-echo\" systems has fewer charge regions, and the polarity of charge at 0°C tends to be positive compared\nto the more complex profiles in squall line MCSs. The more complex squall line structure may be related to\nthe more variable shear regions in those systems.\nA strategy was designed for obtaining air motions in precipitation using two dual-beam Doppler equipped\naircraft. This strategy will be used in TOGA COARE to study momentum fluxes and budgets in MCSs. An\nextensive error analysis to evaluate various flight strategies found that only one satisfactory strategy was\npossible: to fly the two aircraft along parallel tracks between 20 and 60 km apart. Fortunately, this flight\nstrategy is reasonably simple logistically, and also enables very reliable air motions to be deduced. In\nparticular, the overdetermined measurements make it possible to use terminal fall speed as upper and lower\nboundary conditions for deducing vertical air velocity through an integration of the mass continuity equation.\nThis capability is extremely important because data from airborne Doppler radars have not always extended\nfully up to the top of the cloud and down to the Earth's surface, where the customary vertical velocity boundary\nconditions can be more reliably imposed.\nAnalyses were completed for two bow-echo type MCSs observed during the COPS-91 project on 8 May\nand 23 May. Airborne Doppler radar data collected by the NOAA P-3 aircraft, which employed the fore-aft\nscanning technique (FAST), offer unprecedented views of the broad mesoscale precipitation and kinematic\nstructure within these intense storms. A key result is that variation of rear inflow strength in the along-line\ndirection appears to modulate the propagation speed (and hence the shape) of the convective cells, and the\nstrongest rear-to-front flow is directed toward the bulging segment of the convective line. This flow pattern\nis closely related to the presence of a low- to middle-tropospheric cyclonic mesovortex that dominates the\ntrailing stratiform region of mature bow-echo systems.\nPlans FY 93\nMCS Research\nContinue work on the COPS-91 data set, concentrating on linking the airborne Doppler radar\nanalyses to other special data sets such as special portable automated mesonetwork (PAM) surface\nmeasurements and Mobile Cross-chain Loran Atmospheric Sounding System (M-CLASS) sound-\nings documenting an intense wake low associated with the 8 May bow-echo system. Collocation\nwith the National Center for Atmospheric Research's (NCAR) Mesoscale and Microscale Meteor-\nology Division will facilitate efforts to compare these unique observations to recent numerical\nsimulations of severe bow-echo systems.\nInvestigate how evaporation rates vary horizontally below cloud base in the stratiform region of\nMCSs and how the pattern of evaporation rate affects the evolving dynamics of the systems with\n82","National Severe Storms Laboratory\nadditional cases from the Cooperative Convective Precipitation Experiment (CCOPE), OK-PRE-\nSTORM, COPS-89, and COPS-91.\nStudy the heat budget of a squall line from CCOPE. In particular, time-dependent Doppler radar\ndata will be used to deduce the perturbation temperature field, and the contribution to the heat budget\nfrom thunderstorm updrafts will be assessed.\nContinue investigations with Center for Analysis and Prediction of Storms (CAPS) scientists on\nstorm initialization to include the effect of missing information in the storm interior on short-term\nforecasts using the new CAPS Advanced Regional Prediction System (ARPS).\nDocument basic dynamics including momentum transports using Doppler-analyzed winds and\nretrieved variables within a distinctly three-dimensional PRE-STORM MCS.\nComplete observational studies of several mesoscale convectively generated vortices (MCVs). One\nwell-defined vortex is being examined primarily with profiler data; others were observed during\nSWAMP in Arizona and northern Mexico.\nApply the University of Oklahoma's (OU's) Straka dynamic cloud model (enhanced with charging\nmechanisms) to simulate early electrification of the 31 July 1984 New Mexican mountain thunder-\nstorm case and compare with Ziegler's kinematic model results.\nTOGA COARE Research\nInitiate analysis of airborne Doppler radar data collected during TOGA COARE to document the\nmomentum flux properties of oceanic convective systems.\nDevelop a new technique for deriving a profile of vertical air velocity from overdetermined Doppler\nradar data and the equation of mass continuity, and apply it to data obtained during TOGA COARE.\nIn this technique, all levels are linked and treated equally SO that the distinction between boundaries\nof the column and internal points in the column disappears.\nDryline Research\nBased on one of the COPS-91 data sets, document variations in structure along the dryline in relation\nto locations of deep convective cloud development.\nInitiate modeling studies of dryline structure using the CSU-RAMS mesoscale model to study the\nthree-dimensional evolution of the dryline on several days during COPS-91.\nGUFMEX AND DATA ASSIMILATION PROJECT\nAccomplishments FY 92\nGUFMEX\nA working group meeting was held in March 1992 to focus on accomplishments since 1988 and plans for\nfuture experiments.\n83","Ten articles related to GUFMEX (Gulf of Mexico project) 1988 were published.\nCoordination was established with the LATEX (Louisiana-Texas) oceanographic experiment in\nGUFMEX. LATEX began in April 1992 and will continue until 1994.\nA masters thesis was prepared on return flow and equilibrium models.\nData Assimilation\nWe collaborated with the OU Computing Sciences Institute on parallel processing applied to hurricane\ntrack prediction. A paper on Hurricane Elena in 1985 was submitted for publication.\nCourses on meteorological data assimilation for computer scientists were developed and offered to\ngraduate students in Meteorology and Computer Science at OU.\nCollaboration with scientists at Pennsylvania State University (PSU) has produced a paper on nonhydro-\nstatic modeling and data assimilation.\nPlans FY 93\nGUFMEX\nSubmit a joint proposal to National Science Foundation (NSF) from cooperative institutes at OU,\nTexas A&M University (TAMU), and University of Wisconsin (UW) to do more field work in 1994,\nwith emphasis on understanding air, sea, and land topographic effects on return flow in the northwest\nGulf. We will address hydrological cycle issues along the Gulf coastal plain and Mississippi basin.\nCoordinate modeling studies with the National Meteorological Center (NMC) and UW to determine\nthe impact of Gulf data and air-sea interaction processes on cool season precipitation forecasting.\nPerform modeling studies with OU collaborators on a diagnostic model to study topographic effects\non low-level jets and on cloud modeling in return flow situations.\nPerform operations research with the Cooperative Institute for Mesoscale Meteorology (CIMMS)\nand National Severe Storms Forecast Center (NSSFC) on synoptic analysis of March 1991-92 return\nflow events and NMC forecasting of the same.\nPerform operations research with UW and the National Weather Service (NWS) Slidell office using\na Special Sensor Microwave/Imager (SSM/I) to access moisture in return flow.\nData Assimilation\nDevelop a proposal with OU Computer Science Institute, Atlantic Oceanographic and Meteorological\nLaboratory (AOML)/Hurricane Research Division, and NSSL to apply parallel processing strategies\nto hurricane problems.\nWork with OU Mathematics Department to develop assimilation methods applicable to\nmeteorology models.\n84","National Severe Storms Laboratory\nDOPPLER RADAR AND REMOTE SENSING RESEARCH GROUP\nAccomplishments FY 92\nStorm Studies\nWe carried out a series of three-dimensional numerical simulations of thunderstorms in which the character\nof the perturbation used to initiate the storm was varied. Both the initial storm and the subsequent storm\nredevelopment are sensitive to the specification of the perturbation. Further analysis of the mechanisms\nleading to the sensitivity is necessary.\nThe effect of changing the midlevel, environmental storm-relative winds on the low-level behavior of\nrotating thunderstorms was investigated using a three-dimensional computer model. Of primary importance\nis the role of the winds in distributing precipitation from the updraft. As the midlevel, storm-relative winds\nintensify, it takes longer for storms to develop significant low-level rotation. Nevertheless, once significant\nrotation is present at low levels, it is more persistent if midlevel, storm-relative winds are strong than if they\nare weak.\nOutput from a three-dimensional cloud model was diagnosed, using vorticity dynamics, to find out how\nrotation first develops at the lowest level (100 m AGL). The first cyclonic vorticity at this level is generated\nby the tilting of quasistreamwise horizontal vorticity in subsiding, evaporatively cooled air, on the eastern\nedge of the cool air outflow. The vorticity changes sign from anticyclonic to cyclonic during descent, owing\nto simultaneous baroclinic generation and tilting. The cyclonically spinning air is then entrained into the\nsouthwest side of the updraft below 100 m and stretched vertically, perhaps resulting in a tornado if the model\nhad finer resolution.\nSimple and efficient formulas were derived for evaluating divergence, vorticity, and their errors from three\nor more observing stations by several different methods. One application of this work is to measure\ndivergence by hexagonal or other small networks of profilers.\nIn a collaborative effort with the South Dakota School of Mines and Technology, a single-Doppler radar\nstudy of two hailstorms that occurred near each other on 11 July 1989 during the North Dakota Thunderstorm\nProject has begun. By determining storm morphology from the radar reflectivity and Doppler velocity\nsignatures, we expect to learn why one storm produced both in-cloud and cloud-to-ground lightning and the\nother produced almost exclusively in-cloud lightning.\nPolarization Studies\nWe explored the utility of polarimetric measurements to discriminate hydrometeor types, with the emphasis\non hail detection and discrimination of its size, measurement of heavy precipitation, identification and\nquantification of mixed phase hydrometeors, and discrimination of ice forms. We analyzed data samples of\npolarimetric measurands from a hailstorm at a range of about 40 km, the first such measurement with good\nresolution of polarimetric variables. At present, interpretation of the measurements is possible only for a\nlimited subset of the data, and it relies on scattering models and self consistency of the measurands. We made\nan attempt to identify regions with dominant hydrometeor types and to quantify the amounts of precipitation.\nHeavy rain shafts were clearly identified from significant values of specific differential phase, which also\nprovided quantitative estimates of rainfall in regions of rain mixed with hail. Use of a hail melting model\nallowed us to estimate the dominant sizes and the breadth of the distribution. We observed a vertically\ncontinuous shaft of negative backscatter differential phase, which we attribute to a narrow range of hail sizes\n(8-16mm).\n85","Forecasting\nWe began analysis of results of the Storm Type Operational Research Model Test Including Predictability\nEvaluations (STORMTIPE) experiment from 1991. The average forecast sounding was more unstable and\nhad slightly greater low-level helicity than observed. Of the 12 days on which the numerical model was run,\nthere were 4 days for which the model forecast was excellent. Of the eight poor forecasts, four appear to be\nassociated with poor initial sounding forecasts and four with good sounding forecasts.\nSTORM-FEST\nThe STORM Fronts Experiment System Test (STORM-FEST) held in FY 92 was the first field program\nof the U.S. Weather Research Program. Its primary goal was to implement and integrate all research and\noperational aspects of the U.S. Weather Research Program that are essential to the success of the major\nmultiscale field experiments in the decade-long program. The STORM-FEST focus was on winter storms,\nincluding the structure and evolution of fronts, embedded precipitation, and associated mesoscale phenomena\nin the central United States. Although precipitation was not abundant in Oklahoma during the experiment,\nthere were three episodes during which simultaneous data were collected by spaced disdrometers, rain gauges,\npolarimetric radar, and WSR-88D radars. This is the first time that such data have been acquired.\nMoisture and Heat Fluxes from Profiler Data\nIt has been theoretically shown that radar reflectivity due to refractive index irregularities in a convectively\nmixed boundary layer could be a sensitive measure of the changes in surface heat fluxes; radar reflectivity\nvaries more than two orders of magnitude with changes in the ratio of sensible to latent heat flux (i.e., the\nBowen ratio). To validate the feasibility of using radars to remotely sense heat flux, we used data from a\nboundary layer profiler (a 33-cm wavelength Doppler radar) installed at Amber, Oklahoma, in support of the\nCOPS-91 experiment.\nWe compared normalized reflectivity profiles with those theoretically computed. The profiles approxi-\nmately follow the \"4/3\" law prediction of the Monin-Obukhov similarity theory, which applies in the lowest\nportion of the mixing layer. The radar reflectivity profiles exhibit a peak value at the top of the mixing layer,\nin agreement with theory. The height of this peak measures the height of the convective layer, and\ncomparisons with M-CLASS soundings provided verification. A profile of spectrum width compares\nfavorably with that predicted by theory. Computations of heat flux from measured spectral width gave a\nvalue higher than expected because spectral width data are not corrected for biases; corrections require power\nspectra data, which were not available.\nMesoscale Convective Systems\nA theoretical study assessed the role of the change of wind with height in a squall line's environment. The\ntheory also took into account the strength (coldness) of the storm outflow. It was established that the stronger\nincreases of wind with height (blowing along the direction the squall line is moving) ahead of a squall line\nfavor longer-lived systems, as shown in other theoretical and numerical modeling studies. In addition, certain\nchanges of wind with height in the middle layers of the atmosphere are conducive to long-lived systems. The\noptimal wind structure is partially dependent on the strength of the cold storm outflow.\n86","National Severe Storms Laboratory\nThis theoretical study was motivated by a Doppler radar-based observational study of unprecedented detail\n(many storms were examined at many different times). A certain class of squall lines was discovered that\nfeatures a solid leading edge radar echo instead of discrete cells. This type of squall line can persist for many\nhours in a steady configuration that is characterized by updrafts tilting very strongly rearward with height.\nThis finding of an optimal squall line structure is different from the supposedly optimal structure of erect\nleading edge cells.\nPlans FY 93\nComplete analysis of the STORMTIPE data, including running the numerical model with observed\nconditions on days when the model forecast was poor.\nDiagnose causes of the sensitivity of storm behavior to the initial perturbation in three-dimensional\nnumerical models.\nContinue planning the 1994-1995 tornado field project, including developing the final operations\nplan, and seek resources to carry out the project.\nComplete an investigation of the storm-environment interactions (pressure and buoyancy fields) that\nled to the splitting storms of 27 June 1989.\nInvestigate the relationship between thunderstorm morphology and the extent of cloud-to-ground\nlightning activity.\nParticipate in planning and data collection for the North Dakota Tracer Experiment in the summer\nof 1993.\nAnalyze polarimetric data obtained with a vertically pointing beam and attempt to discriminate\nbetween liquid and frozen precipitation.\nInvestigate polarimetric measurements of intense precipitation.\nContinue work to verify the theory for squall line structure and longevity.\nDevelop techniques to utilize simultaneous footage of tornadoes and other thunderstorm phenomena\nshot from two angles (stereophotogrammetry).\nSTORM ELECTRICITY AND CLOUD PHYSICS RESEARCH GROUP\nAccomplishments FY 92\nWe worked with the Office of the Federal Coordinator for Meteorology in providing technical and scientific\nexpertise to assist in the procurement of lightning ground strike data for use by federal agencies.\nAnalysis of data relating to electrical aspects of MCSs continues. The electric and kinematic structure of\nan MCS was compared with earlier case studies and models. New hypotheses relating to the charge structure\nwere formulated. The first findings from COPS-91 analysis were presented as a coordinated set of papers\nat the fall annual meeting of the American Geophysical Union, and several more detailed seminars were given\nat universities and NCAR. The COPS-91 data reveal two types of vertical electric field structure in the\n87","stratiform regions of MCSs. The charge structure in the MCS stratiform region is remarkably similar from\none place in an MCS to another, from one MCS to another, and even from one year to another.\nWe continued to develop a three-dimensional numerical dynamic cloud model that contains electrical\nparameters along with the usual meteorological components. This advance utilized NSSL's earlier\nretrieval models.\nVarious studies of the national ground strike network and its use continued. Specific studies examined\nlightning data from several regions. Studies show strong ties of positive ground flashes and low-precipitation\nsevere storms and hail storms. All are part of our efforts to incorporate the lightning ground strike data stream\nwith others in the modernized weather service.\nWe advanced an initial explanation for the relationship of ground flashes and upper-air patterns during\nbursts and breaks in the Southwest Monsoon and put forth questions to be addressed in follow-on research\nand implementation in prediction schemes.\nIn collaboration with Massachussets Institute of Technology (MIT) Lincoln Laboratory, the Federal\nAviation Administration (FAA), other federal agencies, and universities, we collected comprehensive storm\nand lightning data at Orlando, Florida, for research on operational use of lightning.\nNSSL scientists and students from the OU School of Meteorology conducted tests at the Irving Langmuir\nLaboratory for Atmospheric Research in New Mexico. We tested NSSL's modified sonde for use in clouds.\nThe results show that the modification allows the sonde to receive loran for determination of winds and\ntracking in electric fields of at least 100,000 V m ¹, which is typical of thunderstorms. The results were\ncorroborated with flights through storms with such high fields. Use of the modified sonde is also warranted\nin nonthunderstorm stratiform cloud forms, some of which have high electric fields.\nInternational interactions by the group included invited presentations at the Bureau of Meteorology,\nMelbourne, Australia; the National Meteorological Institute, Madrid, Spain; the Japan-U.S. seminar on\nlightning, Toyota City, Japan; and the University of Valencia, Spain; and a keynote paper at an international\nconference in St. Petersburg, Russia.\nPlans FY 93\nWork with the Office of the Federal Coordinator for Meteorology and other components in NOAA\nto develop the use of cloud electrification and lightning data in operations.\nContinue analysis of the COPS-91 data set to determine the electric field, charge structure, and\nprecipitation charge in MCSs and address characteristic aspects of the two types of charge structures,\ncharging mechanisms, and bipolar lightning ground strike patterns.\nAdvance the capability and perform research with the models incorporating electrification and it\neffects in storms.\nAnalyze comprehensive storm and lightning data from Orlando and begin developing in collaboration\nwith NSSL/Forecast Applications Research Group (FAR) operational algorithms using lightning.\nDevelop collaborative research strategy to incorporate lightning data into operational products such\nas one indicating weather prohibited and impacted areas for nationwide use by the FAA.\nContinue to develop understanding and use of lightning data in the Southwest Monsoon.\nWork to increase public awareness of lightning hazards through increased education.\nParticipate in data collection with P-3 in TOGA COARE.\nEvaluate the operational national lightning detection network data stream as part of development of\nits use in operations.\n88","National Severe Storms Laboratory\nREGIONAL WEATHER PROCESSES GROUP\nAccomplishments FY 92\nRegional Studies\nHeavy rain events in central United States\nAn extensive study using the PSU/NCAR mesoscale model (MM4) of a period characterized by several\nvery heavily raining MCSs was completed. It was found that the event could not be simulated well unless\nmesoscale features (e.g., cold outflow boundaries, dryline temperature, and moisture gradients) were\nsubjectively added to the initialization data. Even when these features were included, accurate prediction of\nthe event was dependent on precise timing and location of initial convective developments in the model\nforecast. Convective initiation was extremely sensitive to initial conditions because of widespread moisture\nand instability and weak capping. The results of this work have very important implications regarding the\nreliable use of real-time mesoscale numerical predictions during the warm season.\nStudies of the large-scale environments that produce nighttime rainfalls at Omaha, Nebraska, continued\nthrough the year. Results indicate that there are pronounced synoptic signals, i.e., significantly different from\nclimatology, that precede the events by 6-18 h.\nSurface data preceding, by 6-12 h, the development of large and long-lived MCSs show that these\nconvective events develop and persist in mesoscale regions characterized by pronounced forcing for vertical\nmotion in the lower troposphere. The forcing is diagnosed in this study via the presence and strength of\ncold frontogenesis.\nWeather processes in southwestern North America\nThe group used various data sets gathered during the SWAMP observational period in 1990 to study and\ndocument a wide variety of mesoscale and large-scale weather systems and processes over Arizona and\nnorthwestern Mexico. The group served as coordinator and cosponsor of the Fourth Arizona Weather\nForecasting Symposium, which was held during July. Substantial progress was made in several areas.\nDocumentation of the large-scale settings that bring severe thunderstorms to central Arizona was completed.\nThree distinct patterns were identified, and a specific severe case was examined in detail.\nCareful four-dimensional documentation of the Phoenix summertime heat island is being completed in\ncollaboration with the Salt River Project power company.\nA Geostationary Operational Environmental Satellite (GOES) monsoon raininess index was developed in\ncollaboration with staff at the Phoenix Forecast Office. This approach to documenting the character of each\nyear's monsoon period over Arizona has distinct advantages relative to the historical approach that has used\nclimatological rainfall reports from surface stations.\nThe synoptic environments that lead to widespread rains and also to intermittent dry periods during the\nsummer monsoon were identified using the long-term upper-air sounding data base.\nSatellite data and historical upper-air data were used to establish the character and geographical extent of\nthe monsoon period over southwestern North America. This phenomenon is most distinct over northwestern\nMexico, and we have termed it the \"Mexican Monsoon.\"\nSWAMP pibal data were used to study diurnal wind patterns over northwestern Mexico. These show that\nthe southerly low-level flow, which advects moisture into the United States, often resides entirely below the\n89","850-mb level and is not captured well in large-scale analyses. Further, the summer mean flow at low levels\nis 180° out of phase with that predicted by NWS operational forecast models. The occasional occurrence of\na distinct low-level jet structure over the Gulf of California was documented, and P-3 data were used to\nillustrate the structure of a single event.\nSpecial upper-air soundings taken in the Phoenix area were used to show that the character of the boundary\nlayer varies dramatically and rapidly from periods of \"entrainment drying\" to periods of \"moistening.\" The\npresence of elevated mixed layers, which advect over the Phoenix area from nearby mountainous terrain,\nalso strongly affects the diurnal evolution of the local boundary layer.\nClimate-Related Studies\nLand surface influences on clouds and radiation\nCollaborative work, supported by NOAA's Office of Global Programs, continues with several universities\nand with the National Environmental Satellite, Data, and Information Service (NESDIS) group at Madison,\nWisconsin. A GOES algorithm was developed to determine the presence of shallow cumulus clouds, and\nanalysis of the diurnal trend over a region of the central Mississippi Valley is under way. The midday cumulus\nfrequency has revealed many interesting correlations with land surface characteristics; e.g., cumulus fre-\nquency is enhanced over the forested Ozarks and suppressed over the Mississippi floodplain.\nA collaborative project with the National Aeronautics and Space Administration (NASA) Severe Storms\nBranch used high-resolution GOES infrared data to examine the annual frequency of thunderstorms and\nassociated high cloudiness. The study is illustrating both the annual frequency and the interannual variability\nof summertime storms along a subtropical latitude band that stretches from Florida across the Gulf of Mexico\nto the west coast of Mexico.\nPlans FY 93\nExecute small, collaborative, data gathering exercises in central Arizona and northwestern Mexico.\nThis field work will obtain follow-on data to enhance the SWAMP data bases. It will focus on\nWSR-88D assessments in the Phoenix area and on research data gathering in Mexico. Collaborators\nwill include the NWS Western Region and Phoenix, Arizona State University, the University of\nArizona, the Mexican Weather Service, and the Salt River Project.\nExpand modeling work to include simulation studies on both the storm scale and mesoscale to relate\nthe mode of convective storms to subsequent feedbacks to radiative forcing. This work will be part\nof the Department of Energy's Atmospheric Radiation Measurements (ARM) Program's Southern\nPlains Cloud and Radiation Test Bed (CART) site science activities.\nContinue satellite-based studies of regional convective climatologies and enhance to include work\nof direct relevance to NOAA's Equatorial Pacific Ocean Climate Studies (EPOCS) program.\nExpand studies at Madison to include work on surface feedbacks to cloudiness over the Amazon.\nEarth Radiation Budget Experiment (ERBE) studies will also be expanded and draw on GOES data\nto more precisely define the diurnal cycle of radiative forcing during the summertime over the central\nUnited States.\n90","National Severe Storms Laboratory\nFORECAST APPLICATIONS RESEARCH GROUP\nAccomplishments FY 92\nNEXRAD\nWe continued to enhance experimental versions of the NEXRAD automated algorithms, including the\nstorm identification and tracking, hail detection, mesocyclone detection, and tornado detection algorithms.\nA significant addition to the hail detection algorithm was made, which estimates the size of the largest hail\nassociated with a storm. A data base of more than 30 h of Doppler radar data was perused by radar\nmeteorologists to determine the location of storm cells and mesocyclone and tornado signatures. Severe\nweather reports were collected for these same times. This data base will be used to test, compare, and refine\nfuture NEXRAD algorithms. We conducted a real-time algorithm test and evaluation in the Norman\nExperimental Forecast Facility (EFF) during the spring. NSSL's real-time Doppler radar algorithm system\nwas utilized to run the NSSL versions of the enhanced NEXRAD algorithms. These algorithms were\ncompared in real-time with the NEXRAD algorithms being run on the Operational Support Facility's\nNEXRAD. Analysis of this comparison is nearing completion.\nExperimental Forecast Facility\nThe Norman EFF started operations in December 1991. The first 2 months of operations were spent\npreparing for STORM-FEST. During this experiment the Norman EFF prepared daily forecasts for the entire\nSTORM-FEST domain, but concentrated on the Oklahoma area. During intensive operations periods (IOPs),\ndata were collected using the NSSL Cimarron Doppler radar in conjunction with the WSR-88D radars in\ncentral Oklahoma and other operational data streams. Analysis of these data has begun.\nTerminal Doppler Weather Radar\nWe enhanced and tested in real time experimental versions of the Terminal Doppler Weather Radar\n(TDWR) gust front detection and tornado detection algorithms. NSSL provided Doppler radar support and\nradar meteorological expertise for the FAA's technical field test and evaluation of the first TDWR located in\nOklahoma City.\nDoppler Radar Signatures of Tornadoes\nWe completed a study that examined the single Doppler radar velocity signatures of tornadoes having a\nwide variety of sizes and intensities. The signatures associated with small tornadoes can only be identified\nout to ranges of 30 km or SO; however, large tornadoes can be detected at much larger ranges.\n91","Plans FY 93\nFurther improve and test in real time and off line WSR-88D and TDWR algorithms for detecting\ntornadoes, mesocyclones, hail, and gust fronts.\nExplore the utility of combining Doppler radar, lightning, and profiler data to improve mesoscale\nforecasts and define regions hazardous to aircraft.\nContinue to increase the size of the Doppler radar data base and associated human-determined radar\nsignature ground truth and severe weather report ground truth. Data will be added from WSR-88Ds\nin different locations in the country to ensure that algorithms developed and tested on this data base\nwill perform well in all environments.\nCompare the performance of the NSSL experimental NEXRAD algorithms with the present\nNEXRAD algorithms and algorithms developed by other organizations (e.g., Phillips Laboratory,\nNCAR).\nInvestigate causes of differences observed between the vertical profiles of wind measured by Doppler\nradar and those measured by rawinsondes.\nDevelop the capability to access WSR-88D base data in real time.\nSCIENTIFIC SUPPORT DIVISION\nThe Scientific Support Division continued to support the NSSL scientific goals by providing improved\nfacilities, field, and maintenance support.\nAccomplishments FY 92\nComputing and Data Management\nDespite decreased funding, several significant tasks were accomplished. A5-year computer initiative was\ncompleted for the laboratory, and plans were developed to consolidate the NSSL/Boulder computing facility\ninto the NSSL/Norman facility. Several new workstations were purchased, including SUN IPCs, a SUN\nserver 4/670, two HP Vector systems, and one Silicon Graphics visualization workstation. An additional disk\nsubsystem was added to the pre-Automated Weather and Information Processing System (pre-AWIPS)\nworkstation in support of the EFF. Most of the laboratory's 8 mm 2.3 Gbyte drives were upgraded to\n5 Gbyte drives.\nTo reduce maintenance costs, several older VAX disk drives were replaced with newer disks having three\ntimes the capacity, a VAX 11/750 was released for surplus, and a VAX 11/780 is being prepared for surplus.\nSeveral PCs were upgraded during the year, most notably the graphics department's PC which was enhanced\nto a 50 MHz 486, reducing graphics processing time by as much as 66%. An optical scanner was purchased\nand network wide CD-ROM services were provided through a new DEC InfoServer 150 network virtual\ndevice server. Development continues on an advanced Doppler display and editing system (NDREX) in\npreparation for the TOGA COARE field experiment.\n92","National Severe Storms Laboratory\nCimarron Doppler Radar\nThe Cimarron radar was fully operational during the entire year. Cimarron provided real-time estimates\nof reflectivity, mean velocity, spectral width, differential reflectivity, and differential phase. In addition, a\nparameter indicating the cross-correlation function between received horizontal and vertical intensity\ncomponents was implemented. Data recording and playback capabilities were enhanced with the addition\nof an 8 mm cassette recorder. The Cimarron radar was used to collect data during STORM-FEST and has\nbeen used extensively to support the FAA TDWR program.\nMobile Laboratories\nConstruction of the NSSL3 transportable laboratory housed in an 8 by 16 ft trailer was completed. A\nfour-wheel-drive pickup truck was obtained from the General Services Administration (GSA) to pull the\ntrailer in all terrain conditions, including mountains. All the NSSL CLASS systems (two mobile, a\ntransportable unit, and a hand-carried unit) were used to gather upper air and surface data during STORM-\nFEST held in February and March 1992. From April through June, the hand-carried unit was loaned to TAMU\nand installed at the Weather Service Forecast Office in Houston, Texas. In June, the NSSL2 mobile laboratory\nwas deployed to Arizona to evaluate how well the new south-central loran chain improved the wind\ncalculations in that part of the country. The NSSL2 was also on display at the Fourth Arizona Weather\nSymposium in Phoenix in June. Two Global Positioning Satellite (GPS) receiving systems were installed\nand tested. The NWS also asked NSSL to test loran coverage in the mountainous areas at Grand Junction,\nColorado, and Salt Lake City, Utah. Soundings were taken at these locations, and a report is being forwarded\nto NWS headquarters. Soundings are being taken at NSSL to compare with the NEXRAD Velocity-Azimuth\nDisplay (VAD) and profiler winds. Discrepancies in these winds obtained during low-level jets are being\ninvestigated. Two NSSL vehicles were loaned to the ARM project in Lamont, Oklahoma, to help get the\nproject started. The NSSL1 mobile laboratory was deployed to Langmuir Laboratory in New Mexico during\nJuly for storm electricity studies. After returning to Norman, NSSL 1 was disassembled and returned to GSA.\nA new vehicle is in-house awaiting funding approval and suggestions on configuration. A total of 500 upper\nair soundings were collected.\nPlans FY 93\nPurchase an optical jukebox system that will reside on the network and be serviced through a DEC\nInfoServer 150 virtual device server.\nPrepare groundwork for upgrading or replacing the DEC VAX cluster, which functions as the\nlaboratory's primary server.\nContinue to move toward a distributed computing environment through the purchase of workstations.\nEnhance the Cimarron radar performance in the spectral domain.\nContinue to develop quality control tests and procedures to assure high quality data products.\nReplace the real-time interface and add a new color display system.\nReplace NSSL1.\nParticipate in SWAMP-II next summer in Arizona and Mexico using all four units.\n93","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nWAVE PROPAGATION LABORATORY\nBoulder, Colorado\n(303) 497-6291\nSteven F. Clifford, Director\nThe Wave Propagation Laboratory's (WPL's) mission is to improve the Nation's geophysical research and\nservices by developing, demonstrating, and transferring cost-effective remote measurement systems. To\nachieve this goal, WPL performs the following functions:\nConducts detailed theoretical and experimental studies of the interactions of acoustic and electro-\nmagnetic waves with the atmosphere or ocean, with particular reference to the use of such interactions\nfor remote sensing.\nDevelops and experimentally evaluates new geophysical remote-sensing concepts and systems.\nApplies the unique advantages of newly developed remote-sensing techniques to atmospheric and\noceanic research.\nImproves the Nation's atmospheric and oceanic research, and forecasting and warning services,\nthrough transfer of remote-sensing technology.\nWPL's contributions to weather research support NOAA's largest and most important single service,\nnamely, weather forecasts and warnings. This service is required on many space and time scales. WPL's\nremote-sensing program includes contributions on all scales from the micrometeorological to the global.\n95","WEATHER RESEARCH\nMICROMETEOROLOGY\nAccomplishments FY 92\nSensor Development\nThe performance of various standard Doppler estimation algorithms was compared with the theoretical\noptimum performance (the Cramer-Rao bounds) for heterodyne lidars and for idealized direct detection lidars\nin which signal shot noise is the only source of error. Although in principle the heterodyne lidar is some what\ninferior when compared with this standard, it is realizable, and it has the advantages of immunity to\nbackground light and the flexibility and simplicity available from filtering in software rather than with optical\ninterferometers. One important limitation of the heterodyne system, arising because wideband local oscillator\nshot noise is generated at the photodetector prior to spectral filtering, can be overcome by averaging either\nspectral or correlation function estimates obtained using speckle diversity techniques, e.g., multiple trans-\nmitted laser pulses or signals obtained from multielement photodetector arrays. The amount of averaging\nrequired, which is an essential input for designing a heterodyne lidar for Doppler measurements, was\nspecifically quantified. Several practical algorithms can be used for optimal estimation after averaging and\nwith proper tuning.\nA new ultraviolet (UV) incoherent Differential Absorption Lidar (DIAL) system for measuring ozone (O3)\nspecifically in the lower 3 km of the atmosphere was completed and is undergoing tests. The wavelength\npair 266/289 nm has been chosen to obtain the high differential absorption coefficient needed for high spatial\nand temporal resolution of the measurement. The on-line wavelength (266 nm) is provided by a frequency-\nquadrupled Nd: YAG laser. The off-line wavelength (289) nm is generated by shifting the residual energy of\nthe second harmonic of the YAG laser from 532 nm to 632.5 nm through a D2/He/Xe Raman cell, and\nsubsequently sum-frequency mixing the above two wavelengths through a beta nonlinear crystal. The\ninnovative hardware design and improved data processing technique should enable this lidar to measure ozone\nconcentration profiles with better spatial resolution (typically 100 m) and higher accuracy in a relatively\nshorter time period (seconds) than existing ozone lidars.\nA novel, compact, CO2 pulsed Doppler lidar operating in a semi-autonomous mode at a high-pulse\nrepetition rate was deployed in the Atlantic Stratocumulus Transition Experiment (ASTEX). This lidar was\nconstructed entirely in-house and utilizes contemporary diffusion-cooled radio-frequency discharge excita-\ntion technology. The system was designed to have a flexible set of operating parameters, including variable\npulse widths (0.1-10 us), pulse repetition rates (1 kHz), and wavelengths (9-11.3 um). Preliminary\nmeasurements from ASTEX indicate a velocity measurement accuracy of approximately 10 cm s ¹\nTo develop better tracers for studying complex atmospheric flows and turbulence, field measurements\nwere conducted to evaluate how successfully a wavelength-diverse lidar can simultaneously map multiple\ntypes of fluorescent tracers. Preliminary results were in qualitative agreement with predicted performance.\nTechniques using CO2 lidar to observe microphysical properties of clouds were refined or compared with\nmeasurements by other instruments. These include a lidar/radar method to measure the effective radius of\ncirrus particles and a lidar method to estimate the mean or effective radius of cloud dropsize distributions. A\nmultiwavelength method to discriminate ice, water, or mixed-phase clouds was proposed, and analytical\nevaluation of its accuracy is in progress.\n96","Wave Propagation Laboratory\nAnalysis of remote sensing observations of a destructive freezing rain event was completed, yielding new\ninsights into the morphology of this extremely damaging phenomenon.\nResearch\nThe theory of heterodyne lidar antenna systems was revisited in light of conflicting results in the literature.\nFigures of merit (e.g., antenna efficiency, heterodyne efficiency) were recalculated for several beam\ngeometries. The theory underlying the design of adaptive software filters for return power measurements\nusing heterodyne lidars was also reviewed, partly to prepare for DIAL experiments with a high repetition\nfrequency lidar in the coming year.\nA new offset Cassegrain antenna for WPL's cloud-sensing radar was installed and used during the First\nInternational Satellite Cloud Climatology Program (ISCCP) Regional Experiment (FIRE II). The antenna\nwill significantly improve present capabilities for measuring depolarization, a parameter dependent on the\nshape and orientation of ice crystals.\nThe excellent velocity measurement capability of our cloud radar allowed us to develop a novel method\nfor determining ice particle fallspeeds in cirrus clouds. Because an average of vertical air motion over about\n1 h or longer in cirrus clouds is expected to be nearly zero, such an average of Doppler velocities measured\nwith a zenith-pointing antenna produces good estimates of particle fallspeeds that depend systematically\non temperature.\nA description of a two-wavelength radar method for quantitative snowfall determination was published.\nThe method takes advantage of the differences between Rayleigh and non-Rayleigh scattering at the\ntwo wavelengths.\nPreparations for the Leads Experiment (LEADEX) field program were completed in mid-March. The\nfield program, which lasted for 6 weeks, was held 150 miles north of Prudhoe Bay, Alaska. Three portable,\nintegrated surface micrometeorological and vertical Doppler sodar units were designed and constructed for\nhelicopter deployment at the lead sites. Four leads, ranging in width from 50 m to 1.2 km, were studied. A\nspecially constructed micrometeorological tower package, a 915-MHz wind profiler, a lidar ceilometer, a\nDoppler sodar, and a unique three-point microbarograph system developed at WPL were deployed at the\ncentral ice camp and operated continuously throughout the experiment. Scientists from WPL were also\ninvolved in NOAA P-3 research flights.\nWe participated with a network of five lower-tropospheric profilers in the field phase of the Storm-scale\nOperational and Research Meteorology Fronts Experiment System Test (STORM-FEST). Additional\nsupport was provided to STORM-FEST through the implementation of near-real time computation of the\nkinematic properties of the windfield, including the application of advanced WPL editing procedures to the\nprofiler moment data from the NOAA Wind Profiler Demonstration Network (WPDN). To support interpre-\ntation of profiler data, we participated in three special research aircraft flights over the dense network,\nmeasuring wind, temperature, and humidity structure functions. This data set will be used to evaluate recent\nanalyses of the spatial and temporal sampling requirements for profiler networks.\nPlans FY 93\nContinue the analyses of two midlatitude winter storms using data from the STORM-FEST field\nexperiment to study the structure, evolution, and coupling of fronts, jets and precipitation. Special emphasis\nwill be placed on documenting the interaction of fronts that were part of a significant cold-air outbreak in the\ncentral U.S., and on examining the development of multiple-vortex structure with a horizontal scale of\n500 km in a cyclone. We will continue lidar studies of clouds by analyzing lidar measurements, in combination\n97","with other observations, obtained during the FIRE II cirrus and ASTEX marine stratocumulus field\ncampaigns; a modeling component will also be included in the stratocumulus cloud analysis.\nWe will evaluate the capability of our newly developed ultraviolet and small CO2 infrared lidars for\nmeasurement of atmospheric species and fluxes through field comparison studies.\nWe plan to evaluate the cloud-observing potential of a WPDN profiler by operating our 8-mm-wavelength\nradar with its new offset Cassegrain antenna alongside of a network wind profiler at Platteville, Colorado.\nThe ability of a network profiler to monitor cloud properties would be an unanticipated benefit from the\nnetwork now operating across the Midwest.\nMESO-BETA AND MESO-GAMMA SCALES\nAccomplishments FY 92\nSensor Development\nEight-millimeter radar observations of nonprecipitating clouds were coordinated with lidars, radiometers,\nand other sensors to infer the microphysical structure and radiative features of cirrus clouds in FIRE II and\nmarine stratus clouds in ASTEX. These multiagency studies will clarify the role of clouds in climate change.\nPreliminary investigations with our scanning 8-mm-wavelength Doppler radar used during ASTEX reveal\nthe presence of small, weakly reflecting, but long-lived, convective cells 1 km tall, in which the cloudy air\nis formed within a small region (1 km diameter) of the marine boundary layer. These cells, recognizable by\na vertically stacked convergence/divergence couplet, create a cloud mass over an area 1000 km2 This\nunexpected observation is being evaluated for its impact on the marine boundary layer.\nFrom the Cloud Lidar and Radar Exploratory Test (CLARET) data sets, relationships between the\nradar-derived ice content of cirrus clouds and the infrared irradiance of these clouds were discovered. Such\nrelationships may be useful for improved modeling of clouds in climate change scenarios. Similar analyses\nare being conducted with the FIRE II and ASTEX data sets.\nResearch\nObservations from 50- and 404-MHz radar wind profilers with Radio Acoustic Sounding System (RASS)\nwere combined with Geostationary Operational Environmental Satellite (GOES) imagery to document the\nnonstationarity of trapped lee waves and a transition of gravity wave type. Because of the availability of\nfrequent wind and temperature profiles, changes in the wave structure were related through linear theory to\nchanges in the wave environment on time scales of 1 h.\nThe sensitivity of the NOAA 404-MHz wind profilers to cloud and precipitation was verified using\nsimultaneous surface precipitation measurements, as well as satellite-derived cloud-top heights. It was\nestablished that the 6-min moment data contained sufficient information to identify intervals when precipi-\ntation occurred at the surface and that convective precipitation could be distinguished from stratiform\nprecipitation.\nAnalyses of multiple remote sensor observations of nonprecipitating clouds from the CLARET-I and II\nare now complete. This work combined radar measurements with those of lidars and radiometers. Results\nshow that the median ice particle diameter and concentration within a cirrus cloud can be estimated by\ncombining radar data with data from a narrow-band IR radiometer.\n98","Wave Propagation Laboratory\nKnowledge of the location and amount of supercooled liquid water (SLW) in clouds would be extremely\nvaluable for helping aircraft avoid regions of hazardous icing and for effective cloud-seeding operations. A\nnew radar method for obtaining such information has been field-tested using simultaneous observations with\ntwo different wavelengths that are subject to greatly different levels of attenuation by liquid water. A final\nreport on the technique is being prepared.\nPlans FY 93\nThe nonstationarity of mountain waves will be explored through additional case studies and comparisons\nof simulations with a two-dimensional, nonhydrostatic numerical model with the objective of quantifying\nthe effects of the changing wave environment on wave structure.\nThe sensitivity of the NOAA 404-MHz wind profilers to clouds and precipitation will be examined in a\nvariety of meteorological conditions.\nWe will direct and participate in the 1992-1993 Eastern Pacific Medium-range Prediction experiment, a\ncollaboration between NOAA/WPL, National Meteorological Center, European Centre for Medium-Range\nWeather Forecasting, and the U.S. Air Weather Service.\nAnalysis of data from the Winter Icing and Storms Project (WISP), augmented with data from measure-\nments, will allow us to determine the feasibility of differential attenuation to detect SLW in mixed-phase\nclouds, a serious hazard to aircraft. Based on the results of this analysis, a decision will be made about the\ndevelopment of a two-wavelength radar designed specifically for SLW detection.\nWe will complete analyses of rich sets of observations obtained with our 8-mm-wavelength radar in the\nFIRE II and ASTEX experiments, and the results prepared for publication.\nWe have established collaborations with cirrus and marine stratus cloud modelers, and are working with\nthem to incorporate ice water flux into cirrus models and vertical velocity statistics into models of marine\nclouds. Data required to satisfy these critical modeling needs have been obtained during FIRE and ASTEX.\nFollowing final data editing, we will begin analysis of the WPL lower tropospheric network and WPDN\ndata obtained during STORM-FEST.\nWe will use the Boulder Atmospheric Observatory facility and local profilers to demonstrate the value of\nremotely sensing the changes in cloud microphysics prior to the precipitation phase, including the role of the\nice/water transitions at the melting level.\nSYNOPTIC AND MESO-ALPHA SCALES\nAccomplishments FY 92\nSensor Development\nThe possible role of conditional symmetric instability (CSI) as a significant mesoscale instability for\nproducing or enhancing precipitation has only recently been recognized through theoretical and modeling\nstudies. Our own model simulations of idealized CSI have revealed several mesoscale structures associated\nwith CSI and shown its net effect on a model atmosphere. These structures include a strong correlation\nbetween the slantwise updraft and subgeostrophic along-front flow during the CSI growth stage, and the\nformation of mesoscale areas of inertial instability, shallow potential instability to upright convection, and\nnegative dry potential vorticity. Some of the simulations also suggest that CSI or dry symmetric instability\n99","(DSI) may be a dynamical cause of the formation of the anvil region of deep upright convection. As better\nobservational data become available, these modeling results will aid in their interpretation.\nGuided by theories of rotating flow over topography, we analyzed past data from the South Pole, including\na 30-year rawinsonde data set and remote sensing observations from 1977 and 1978. We found that trends\nin lower stratospheric lapse rate extend over 30 years when the quasi-biennial oscillation is removed. This\nsuggests the hypothesis that ozone minima have a strong dynamical consequence for tropospheric circulations\nin the austral spring, and can be self-perpetuating once formed because of the binding of the polar vortex to\nthe underlying terrain.\nStudies of mesolow formation along the Colorado Front Range using 915-MHz profiler data from the\nFront-Range Air Quality Study (FRAQS) show that mesolows form during the acceleration phase of upstream\nwinds over the Continental Divide.\nResearch\nWe completed the analysis and two formal publications on the Experiment on Rapidly Intensifying\nCyclones over the Atlantic (ERICA) 45 January 1989 extratropical marine cyclogenesis event. The\nsynoptic-scale and mesoscale analyses prepared for these publications are now being used to validate the\nrealism of similar structures and physical processes simulated in high-resolution numerical weather predic-\ntions of this ocean storm.\nThe use of a boundary-layer RASS to measure vertical heat flux has recently received considerable\nattention. In comparison with tower-mounted turbulence sensors, significant differences have been found in\nthe heat flux spectra using the two methods. These early experimental results will lead to ongoing studies\nusing tower measurements as a reference.\nBecause clouds and insects can seriously affect the physical interpretation of radar profiler measurements,\nstudies of these effects are under way. We have already found that profilers can sense a number of\nmicrophysical properties that are important in the correct modeling of cloud effects on radiation budgets. For\ndrop sizes greater than 100 um (drizzle and heavier), size distributions spanning 10 orders of magnitude can\nbe monitored continuously in height and time. In turn, these distributions can be converted to spectra of\nliquid water and flux (rain) within precipitating clouds.\nOur cooperative research program with the California Air Resources Board has continued, focusing on\nthe application of 915-MHz wind and temperature profilers to the study of mesoscale pollutant transport. An\narray of these profilers deployed in northern California in 1991 has demonstrated the importance of mesoscale\nphenomena such as topographic channeling, mountain-valley circulations, sea breezes, and terrain-induced\nvortices in determining regional air quality. Diurnal and seasonal variations in transport effectiveness have\nbeen documented by computing monthly averages of 24-h time-height cross sections of wind and temperature.\nThe Tropical Ocean Global Atmosphere Tropical Instability Wave Experiment (TOGA TIWE) cruise took\nplace between 18 November and 22 December 1991. Approximately 21 days of air-sea flux data were taken\non the Equator at 140°W longitude. This cruise marked the first time a full flux measurement system, a wind\nprofiler, and a lidar ceilometer were operated simultaneously at sea. All systems operated without failure.\nThe cruise also marked the first attempts at real-time ship motion corrected flux measurements, and is one\nof the most complete boundary/surface layer extended data sets ever obtained over land or sea. A diskette\ncontaining the 1-h summary files was distributed to several laboratories and universities. The fluxes were\nexamined for consistency; covariance (corrected and uncorrected), inertial dissipation, and bulk fluxes were\nall compared. We are now processing the remote sensing data to create a special data base, including surface\nfluxes, cloud-base height, cloud thickness, albedo, fraction, and other cloud statistics for comparison with\nsatellite data and simple models.\n100","Wave Propagation Laboratory\nProgress on planetary boundary-layer (PBL) profiler signal interpretation has led to papers on radar\nobservations of humidity variability in and above the marine planetary boundary layer and on the humidity\nand temperature sensitivity of clear-air radars in the convective PBL. The TIWE cruise, which included\nmeasurements of wind profiler Cn2, surface fluxes, and cloud-base height, and the use of rawinsondes, is\nbeing used to extend this work to the cloudy PBL regime. The ASTEX field program will provide a second\ndata set that will include aircraft overflights. We are exploring the issue of measuring Cn 2 inside clouds for\npossible use in diagnosing cloud geometry and microphysical properties.\nPlanning and preparation for ASTEX was completed and arrangements were made for installation and\noperation of the WPL shipboard turbulence flux measuring system on the Malcolm Baldrige in cooperation\nwith NOAA's Atlantic Oceanographic and Meteorological Laboratory (AOML). Construction of a unique,\nintegrated, sonic anemometer-ship motion measurement system was completed and the instrument was used\non ASTEX. The cruise was held in the Azores/Madeiras region of the Atlantic Ocean between 1 and 30 June\n1992. In addition to the variables measured for TIWE, integrated cloud liquid water content was obtained\nby the WPL microwave radiometer group.\nPlans FY 93\nThe analysis and numerical simulation of extratropical cyclogenesis and its associated internal mesoscale\nstructure and processes will continue.\nWe will investigate the relationships between physical and radiative properties of clouds using ship and\nsatellite data from field measurement campaigns such as TIWE and ASTEX.\nWe will continue our analysis of lower tropospheric turbulence structure and parameterizations using a\nunique data set gathered during the California Transport Study. This analysis will include data from a\n915-MHz radar wind profiler with RASS, routine radiosonde soundings, a monostatic sodar, a laser\nceilometer to provide aerosol layer depth, and extensive surface turbulent flux measurements. Analyses will\nalso focus on the study of mesoscale eddies, marine air intrusions, and the development of a variety of\nthermally driven circulations, particularly over the western foothills of the Sierra Nevada.\nAIR QUALITY\nAccomplishments FY 92\nSensor Development\nLidar wind measurements obtained near the Department of Energy's Rocky Flats plant during February\n1991 were analyzed to study the interactions between the thermally forced exit jets from nearby canyons and\nlarger-scale processes. An exit jet was observed issuing from Eldorado Canyon during each of five cases\nstudied. Characterizing flow interactions is important to understanding diffusion of airborne contaminants\nreleased in the vicinity of the plant.\nAnalysis of lidar observations of the sea breeze showed the vertical and horizontal growth of the sea-breeze\nlayer in the morning, but, surprisingly, no compensatory return flow. Veering of the windfield in the afternoon\ndue to Coriolis effects was also not observed. We concluded that absence of these normally observed\nsea-breeze features resulted from the combination of cold offshore water, rugged inland topography, and\nstrong atmospheric stability.\n101","Wind fields measured using the WPL Doppler lidar during the Grand Canyon field experiment showed\nthat flow in the canyon is strongly influenced by external forcing. Although winds at the bottom of the canyon\nwere shown to be thermally forced under light wind conditions, strong synoptically forced winds were often\nobserved to penetrate to the floor of the canyon.\nStudies of the stratospheric aerosol injected by the eruption of Mt. Pinatubo continue. The WPL CO2 and\nruby lidar systems are being used to make simultaneous measurements at 10.6 and 0.694 um. Differences in\nthe backscatter at the two wavelengths as a function of altitude are used to track changes in the vertical profiles\nof the aerosol particle size distributions. The particle size distribution is important to understanding the impact\nof the stratospheric aerosol on climate and the destruction of stratospheric ozone.\nResearch\nSeveral 915-MHz wind profilers, two equipped with RASS, were deployed in Nevada and northwestern\nArizona during 1992 in support of Project MOHAVE (Measurement of Haze and Visual Effects). Preliminary\nanalysis of these data shows that the complexity of terrain influences flows in the region, and although the\ndata enhance our understanding of these flows, the information reveals the difficulties in modeling pollution\ntransports in this region.\nA single 915-MHz wind profiler was successfully operated during the winter of 1992 on the top of\n2.1-km-high Mingus Mountain, Arizona. This unique deployment was accomplished in cooperation with the\nArizona Department of Water Resources to study winter hydrology in this important watershed, and\nparticularly to study the cloud physical processes of winter precipitation over high terrain.\nDuring the summer of 1992, 915-MHz wind profilers with RASS were operated for the second Rural\nOxidants in the Southern Environment (ROSE II) experiment, located in rural, heavily forested Alabama,\nand for the Southern Oxidant Study, located near Atlanta, Georgia. These profilers were used to determine\ntransport patterns of ozone precursors from both biogenic and anthropogenic sources. The RASS temperature\nprofiles and radar reflectivity provide information on the vertical depth of mixing of these precursors. These\nmeasurements were supported with boundary-layer turbulent flux and aerosol-layer depth measurements\nusing a sonic anemometer and laser ceilometer.\nPlans FY 93\nWe will apply lidar techniques for the study of atmospheric boundary-layer processes through analysis of\nobservations obtained at Rocky Flats and the Grand Canyon, as well as intercomparison experiments in\npreparation for the upcoming Boreal Ecosystem-Atmosphere Study (BOREAS).\nA 1-year study will be carried out in the southern California bight area using a network of 915-MHz\nprofilers to better understand mesoscale variability in the marine boundary layer.\nWe will continue our analyses of surface layer turbulent pressure fluctuation data, with an emphasis on\nthe pressure transport term in the turbulent kinetic energy equation. We will also investigate the role of\npressure fluctuations in controlling the dynamics of turbulent coherent structures.\nWe will deploy the first 915-MHz radar wind profiler with RASS to Amundsen-Scott South Pole Station\nfor a full year study (November 1992-November 1993) of lower tropospheric dynamics.\n102","Wave Propagation Laboratory\nCLIMATE\nAccomplishments FY 92\nCloud modeling studies have yielded parameterization schemes of important cloud microphysical proc-\nesses. These schemes will enable more accurate representation of clouds in general circulation models; the\ncondensation scheme provides important parameters such as droplet concentration and cloud droplet effective\nradius, while the evaporation parameterization enables assessment of subcloud evaporation.\nThe WPL 1-joule Doppler lidar acquired a rich data set during the FIRE II cirrus experiment in southern\nKansas. Lidar observations are being analyzed in context with observations from other instruments to provide\ninformation on bulk morphology, particle sizes, oriented particles, and wind fields within cirrus clouds.\nWe continued to explore techniques that combine data from different remote sensors to derive meteoro-\nlogical products. We used a new UNIX-based version of the International Television and Infrared Observa-\ntion Satellite (TIROS) Operational Vertical Sounder (TOVS) Processing Package to profile temperature and\nhumidity by combining ground-based RASS, commercial aircraft Aeronautical Radio Incorporated (ARINC)\nCommunications Addressing and Reporting System (ACARS) data, and space-based TOVS measurements.\nThe profiles were then compared with nearly simultaneous radiosonde data. We continued progress toward\nthe retrieval of humidity and cloud liquid water profiles from an integrated system composed of a 2-A\nmicrowave radiometer, a lidar ceilometer, and a wind-profiling radar equipped for RASS.\nA Fourier transform Infrared Sounder (FIRS), three-channel steerable radiometer, and calibration system\nwere tested during the FIRE/SPECTRE (Spectral Radiance Experiment) campaign in Coffeyville, Kansas.\nThe instrument operated with no difficulties for the duration of the campaign, and provided excellent\ncomparisons of clear-sky measurements and calculations based on MODTRAN (moderate resolution\natmospheric radiance model for the infrared). The potential of the instrument for providing unique measure-\nments on clouds was also demonstrated. This instrument will be a component of an integrated sounding\nsystem and will provide important cloud and radiation measurements.\nWe completed development and testing of the dual-frequency, microwave radiometer that operates at 23.87\nand 31.65 GHz for aircraft deployment. Following successful laboratory tests and antenna pattern measure-\nments, flight certification of the radiometer and its external antenna was obtained from the Federal Aviation\nAdministration (FAA). This new operational airborne instrument will benefit many areas in atmospheric\nresearch, including climate and global change, severe storms, and aircraft icing.\nAn acoustic observatory was operated continuously during the winter of 1991-1992 to evaluate the\npotential for avalanche detection. The observatory was also used in a collaborative study with NASA to\ndetermine the long-distance acoustic limits for detection of severe weather. The data sets obtained are\nbeing analyzed.\nA patent was obtained for sound transmitter innovations, and an acoustic testbed for objective evaluation\nof developments has been designed and is being tested.\nWe participated in five major field experiments in 1992. The first was WISP-91, an FAA-sponsored\naircraft icing experiment. Data from three Microwave Water Substance Radiometers (MWSRs), RASS, and\nNational Weather Service (NWS) ceilometers were combined to derive aircraft icing nowcasts. Our WISP\nparticipation also included joint observations with the three-channel steerable radiometer from our WPL\nThermodynamic Profiling Group, and the two-frequency radar from the WPL Radar Meteorology Group.\nWe operated a dual-channel radiometer near Norman, Oklahoma, as part of STORM-FEST.\nWe continuously operated microwave and infrared radiometers on Porto Santo Island, Madeira, during\nASTEX, and began a 1-year unattended operation of microwave and infrared radiometers there. Another\n103","ruggedized radiometer was successfully operated on the NOAA research vessel Malcolm Baldrige during\nASTEX.\nPlans FY 93\nWe will analyze data taken in WISP-90, WISP-91, and WISP-92, in which data from four MWSRs and\nother WPL sensors will be applied to aircraft icing forecasts. This project is in cooperation with the National\nCenter for Atmospheric Research (NCAR) and NOAA's Forecast Systems Laboratory (FSL).\nWe will continue to provide support for the National Aeronautics and Space Administration (NASA)\nPropagation Program by operating dual-channel and three-channel radiometers along the Colorado\nFront Range.\nWe will complete analysis of water vapor and cloud data from Coffeyville (FIRE/SPECTRE) and Porto\nSanto, Madeira (ASTEX), and continue to apply these data to climate research.\nWe will continue to develop several instruments and techniques for remote sounding of temperature, water\nvapor, and clouds. These include FIRS, acoustic source and shielding for RASS, evaluation of millimeter-\nwave radiometry for water vapor profiling, the completion of a state-of-the-art, six-channel microwave\nradiometer, and the dual-channel radiometer for aircraft deployment. We will also continue work on\ncombining surface- and satellite-based remote sounder data.\nWe will participate in the Pilot Radiation Observation Experiment (PROBE) experiment in Kavieng, Papua\nNew Guinea, with FIRS and dual-channel radiometers. These experiments are a part of the TOGA Coupled\nOcean-Atmosphere Response Experiment (COARE). We will also operate a dual-frequency microwave\nradiometer on the research vessel Moana Wave.\nWe will continue an experimental program that employs island- and ship-based microwave radiometers\nto provide data for validation of satellite measurements of precipitable water vapor and cloud liquid.\nCurrently, a dual-channel radiometer that will continue observations for 1 year is operating at Porto Santo\nIsland. We will also use the radiometric data in our continued research on the effect of cloud liquid on solar\nradiation and other climate-related research.\nOCEANS AND GREAT LAKES\nAccomplishments FY 92\nSensor Development\nA laboratory experiment was performed that demonstrated delta-k lidar measurements of capillary waves\nand small-scale gravity waves. Two distinct laser scattering mechanisms were observed, and the dominant\nmechanism depends on the incidence angle of illumination. With the information gained, we can evaluate\nthe potential of delta-k lidar for open-ocean measurements of wave spectra.\nWe developed a new method for plotting wind streamlines from vector fields obtained by over-the-horizon\nradar. This technique was demonstrated on data for Hurricane Claudette.\nWe modified the numerical weather prediction model at NASA's Goddard Space Flight Center to integrate\nlarge-area, over-the-horizon radar data.\nOptical spatial filtering techniques for measuring winds and refractive turbulence in the atmosphere were\ntransferred to two small companies under the Small Business Innovative Research program.\n104","Wave Propagation Laboratory\nResearch\nThe matched-field processing (MFP) inversion technique has been applied to compute modal travel times\nand modal pulse spreading of global underwater sound propagation for the El Niño sound speed profile.\nUsing empirical orthogonal functions, the inverted result is much better than that of a conventional\nlinear inversion.\nWe calculated path-integral solutions for wave propagation in a random medium using an orthogonal\nexpansion of the trajectories with up to 100 modes. These calculations were compared with the perturbation\nand asymptotic results in the regions where those approximations are valid.\nThe airborne surface contour radar was flown as part of the Southern Ocean Waves Experiment (SOWEX)\nout of Hobart, Tasmania. These data present the first opportunity for open-ocean comparisons of wind stress\nwith sea-surface topography under a continuum of sea states from gale-force winds down to light and\nvariable winds.\nPlans FY 93\nPreparations are nearing completion for the TOGA COARE intensive field phase (1 November 1992 to\n25 February 1993). Sea-surface directional wave spectra and mean-square slope in Atlantic hurricanes and\nin the Western Pacific using the airborne Scanning Radar Altimeter will be measured. We will also obtain\nsimultaneous over-the-horizon radar data during the hurricane flights. We are collaborating with Pennsylva-\nnia State University and the Woods Hole Oceanographic Institution on three cruises aboard the Moana Wave.\nThe unique WPL seagoing flux and remote sensing system will be the primary meteorological measurement\nsystem for the cruises.\nPacific Ocean acoustic tomographic data will be compared with propagation models, with emphasis on a\ncomplex empirical orthogonal function model applied to a case of a coastal Kelvin-wave-driven Rossby wave\nresponse to an El Niño event.\nWe will observe solar echoes using over-the-horizon radar.\n105","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nCLIMATE MONITORING AND DIAGNOSTICS LABORATORY\nBoulder, Colorado\n(303) 497-6966\nEldon E. Ferguson, Director\nThe Climate Monitoring and Diagnostics Laboratory (CMDL), organized in 1990, conducts research to\nmeasure atmospheric constituents and assess climate fluctuations on a variety of time scales. The Laboratory\noperates remote baseline observatories at Point Barrow, Alaska; Mauna Loa, Hawaii; Cape Matatula,\nAmerican Samoa; and the South Pole, Antarctica. Here, and at numerous cooperative sites, long-term\nbackground monitoring of trace gases, particles, and solar and infrared radiation takes place. The fixed-site\nmonitoring is complemented by occasional field campaigns. Resulting data are analyzed to determine the\nspecies budgets, distributions, sources, sinks, and trends. The Laboratory also analyzes real-time and\nhistorical climate information to develop climate indices, predictive techniques, and evaluations of\npredictions.\nMuch of the Laboratory's research focuses on three contemporary issues: greenhouse gases and climate\nwarming, stratospheric ozone depletion, and El Niño-Southern Oscillation (ENSO) effects on larger space-\nscale weather and climate.\nCARBON CYCLE\nAccomplishments FY 92\nIn situ monitoring of carbon dioxide (CO2) at the four CMDL baseline observatories continued, as did\nmonitoring of methane (CH4) at Barrow and Mauna Loa, and carbon monoxide (CO) at Barrow. In situ\nmonitoring of CO began at Mauna Loa. CO2 and CH4 were measured in flask samples from the global\ncooperative flask sampling network. CO and carbon and oxygen, the stable isotopes of CO2, were measured\nin samples from a subset of the network. The isotopic measurements were done in collaboration with the\n107","University of Colorado at Boulder. We started CO2 monitoring from a very tall tower in North Carolina.\nThe first vertical profiles were obtained via regular (automated) sampling with flasks aboard private aircraft.\nThese last two efforts will better characterize the contribution of terrestrial ecosystems to the global carbon\nbudget and better define the concentrations of CH4 and CO in the vertical. Such data will help constrain the\nways in which vertical mixing is accomplished in models that are used to determine sources and sinks from\nobserved concentrations.\nFurther improvement and field testing of a prototype pumping unit for obtaining flask samples continued;\nin particular, a thermoelectric cooling stage was added to dry the air stream. Drying the air stream is expected\nto improve the measurement of the 18 O/ 16 O ratio of the CO2 in the samples.\nNew flask sampling sites were added: the Gobi Desert in Mongólia, in collaboration with the Mongolian\nState Hydrometeorological Research Institute, and the Cape Verde Islands, in collaboration with the Cape\nVerdian National Meteorological Service.\nAn apparatus was designed and constructed for the analytical calibration of CO2-in-air mixtures based on\nfirst principles, temperature, volume, and pressure.\nAnalysis of the flask methane data from 1983 through 1991 revealed that the rate of increase of atmospheric\nCH4 is slowing. There are two possible causes for the slowing. The rate of destruction of atmospheric CH4\ncould have increased because of slightly higher levels of hydroxyl (OH) radicals in the lower tropical\ntroposphere, or the growth of CH4 sources at temperate and high northern latitudes could be slowing. There\nis some evidence for both viewpoints in our data.\nAn in-depth analysis was done of the role of isotopic ratio measurements of dissolved inorganic carbon in\nocean waters in deciding where the \"missing CO2\" has gone. The isotopic data can shed light on this question,\nbut the accuracy requirements for the data are demanding. An advantage of this method is that uptake of\nisotopic signals by the ocean is strong. The drawback is that isotopic exchange takes place with poorly\ncharacterized biological carbon reservoirs, thus causing some dilution of the isotopic signals.\nPlans FY 93\nContinue monitoring CO2, CH4, and CO through in situ measurements and flask sampling. Expand\nthe flask measurement program to additional sites and to regular sampling aboard aircraft, to better\nconstrain sources and sinks of these carbon cycle gases over the continents as well as the parame-\nterization of vertical transport in three-dimensional atmospheric transport models.\nContinue measurements of stable carbon and oxygen isotopes of CO2 in samples from the flask\nnetwork, in collaboration with the University of Colorado, to distinguish between uptake of CO2 by\nthe terrestrial biosphere and ocean uptake of CO2.\nPerform regular CO2 calibrations to learn the behavior of our calibration system. Compare our results\nto calibrations performed at the Scripps Institution of Oceanography and at the National Institute for\nStandards and Technology (NIST).\nDevelop an independent calibration scale for CH4, based on the gravimetric method.\n108","Climate Monitoring and Diagnostics Laboratory\nNITROUS OXIDE AND HALOCARBONS\nAccomplishments FY 92\nOur automated gas chromatographs (GCs) continued to take samples once an hour for atmospheric\nmeasurement of N2O, CFC-12 (CCl2F2), CFC-11 (CCl3F), CFC-113 (CC12F-CC1F2), methyl chloroform\n(CH3CCl3), and carbon tetrachloride (CCl4) at all four baseline observatories, and at Niwot Ridge in\ncollaboration with the University of Colorado. In addition to the automated measurements, pairs of flasks\nwere collected almost once a week at the four baseline observatories, at Niwot Ridge, at Alert, Canada, in\ncollaboration with the Atmospheric Environment Service (AES), and at Cape Grim, Australia, in collaboration\nwith the Bureau of Meteorology. Flask pairs were also taken at the South Pole, once a week during the austral\nsummer and once a month during the rest of the year. All flasks were returned for analysis in Boulder,\nColorado, for N2O, CFC-12, and CFC-11 determinations by electron capture-gas chromatography (EC-GC).\nThese flasks were sampled at least once a month for atmospheric halons H-1211 (CF2CIBr) and H-1301\n(CF3Br) using EC-GC and cryogenic trapping of a 250-cc sample. Measurements of HCFC-22, HCFC-142b,\nCFC-114, and methyl bromide (CH3Br) began from the flask samples of all seven sites using gas chroma-\ntography-mass spectrometry (GC-MS) and cryogenic trapping of a 200-cc sample. The growth rates of\nseveral important ozone-depleting chemicals, including CFC-11, CFC-12, H-1211, and H-1301, are decreas-\ning with time as the result of both mandated and voluntary reductions in their emissions, and these results\nwere published this year.\nTrace gas standard work for N2O, CFC-12, CFC-11, CFC-113, CH3CCl3, CCl4, HCFC-22, HFC-134a\n(CH2FCF3), HCFC-123 (CF3CHC12), H-1211, and H-1301 continued. The calibration scale for HCFC-22\nand the halons was finalized. Work began on preparing atmospheric standards for CFC-114, CFC-115,\nHCFC-142b, and CH3Br. The GC-MS was modified to detect impurities in our pure gases that are used for\nstandard and reaction rate studies. Work continued on the preparation of atmospheric standards of CH4 and\nCO in collaboration with the Carbon Cycle Group. All low mixing ratio standards prepared in our laboratory\nare made by diluting standards with higher mixing ratios. The methodology to analyze these higher level\nstandards against lower level standards using GC-MS and flame ionization detection-gas chromatography\n(FID-GC) was developed and will enable an evaluation of the stability of our standards.\nAn automated GC, the Airborne Chromatograph for Atmospheric Trace Species (ACATS), was deployed\non the National Aeronautics and Space Administration's (NASA) ER-2 (Earth Resources) aircraft during the\nAirborne Arctic Stratospheric Expedition (AASE-2) from October 1991 through March 1992. This instru-\nment, developed with the Aeronomy Laboratory, measured in situ CFC-11 and CFC-113 once every 2 minutes\nat altitudes as high as 21 km during 26 flights based out of Moffett Field, California. These measurements\nprovided high time resolution estimates of the total inorganic chlorine that is responsible for stratospheric\nozone depletion.\nAtmospheric and surface water concentrations of N2O, HCFC-22, CFC-11, CFC-113, CH3CCl3, and CCl4\nwere measured aboard the University of Southern California research vessel, John Vickers, once every hour\nover a cruise track in the North and South Pacific Oceans during the World Ocean Circulation Experiment\n(WOCE). Dissolved N2O at depth was measured with a head space sampler and EC-GC. One of the purposes\nof this experiment was to estimate the loss of halocarbons in the surface waters of the Pacific Ocean via\nhydrolysis or biological destruction. This work will complement earlier published work on the oceanic sink\nof methyl chloroform in the tropical Pacific Ocean studied during the third Soviet and American Gas and\nAerosol (SAGA-3) experiment.\n109","Plans FY 93\nContinue routine monitoring by in situ analysis at five sites for N2O, CFC-12, CFC-11, CFC-113,\nCH3CCl3, and CCl4, and by collection of flasks at seven sites for N2O, CFC-12, CFC-11, CFC-113,\nCFC-114, CH3Br, HCFC-22, H-1211, and H-1301.\nInstall a new automated EC-GC system for measuring N2O, CFC-12, CFC-11, CH3CCl3, and CCl4\nin flasks, and add more flasks to our network. Construct and install automated GCs at the CMDL\ntower site in North Carolina, as a collaborative study with the Carbon Cycle Group, at Harvard Forest,\nMassachusetts, with Harvard University, and at Alert, Canada, under cooperative agreements to help\nto quantify the sources and sinks of trace gases.\nParticipate on NASA's Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE-\n1) to conduct measurements of in situ CFC-11 and CFC-113 during the boreal fall and spring in the\nsubtropical stratosphere along with measurements of O3, N2O, HCI, NO, NO, NO2, and CIO by other\nLaboratories.\nUpgrade the five existing in situ GCs to measure HCFC-22 and to perform a complete calibration\ncurve each day.\nContinue to develop GC-MS and enhanced EC-GC technology to measure the new substitute CFCs,\nthe HCFCs and HFCs, in the atmosphere. Obtain first measurements of background air for some of\nthe newer compounds.\nDevelop an independent calibration scale using gravimetric standards for H2 at relevant atmospheric\nconcentration levels in collaboration with the Carbon Cycle Group.\nAEROSOLS, RADIATION, OZONE, AND WATER VAPOR\nAccomplishments FY 92\nAerosols\nThe aerosol monitoring program continued at the four CMDL baseline observatories. Condensation nuclei\n(CN) concentration and aerosol scattering (Osp) measurements have been made at Barrow since 1976, Mauna\nLoa since 1974, Samoa since 1977, and South Pole since 1974 (Osp since 1979). Each station (except Samoa)\nshows an annual cycle in Osp that is caused by long-range transport. A springtime peak at Barrow is caused\nby transport of pollution materials from midlatitudes. A springtime peak at Mauna Loa is caused by transport\nof desert dust and pollution materials from Asia. A late-winter peak at South Pole is caused by transport of\nsea salt from the surrounding oceans during storm activity. CN concentration shows an annual cycle at\nBarrow and South Pole, but not at Mauna Loa or Samoa. No statistically significant long-term trends were\nfound at any station.\nA new butanol-based CN counter was installed at Samoa. This instrument will replace the General Electric\nCN counter that has operated there since 1977.\nTwo experiments were organized to compare lidar, aircraft, and balloon-borne measurements of aerosol\nprofiles near Boulder, and Laramie, Wyoming. These experiments, the second and third performed over a\n3-year period, were designed to provide a calibration for lidar measurements in the clean region of the\natmosphere. The University of Wyoming was a coinvestigator in this project.\n110","Climate Monitoring and Diagnostics Laboratory\nWe participated in the Arctic Gas and Aerosol Sampling Program (AGASP). This program involved both\nU. S. and Russian flights near the Alaskan Arctic to obtain information about the Arctic Haze phenomenon.\nA General Electric CN counter and a three-wavelength nephelometer were operated on the U.S. aircraft, and\na butanol-based CN counter and a single-wavelength nephelometer were operated on the Russian aircraft.\nA new monitoring station for studying the climatic effects of aerosols was established on Sable Island, 200\nkm southeast of Halifax, Nova Scotia, Canada, in August 1992. This site is subject to long-range transport\nof pollution aerosols from North America, but also experiences very clean conditions. The instrumentation\ninitially deployed at the station measures Osp and CN. Aerosol samples will be analyzed for their chemical\ncomposition (major ions) in two size fractions (<1 um and 1-10 um diameter) by the NOAA Pacific Marine\nEnvironmental Laboratory (PMEL). The station on Sable Island is a near twin of one being established on\nthe west coast of Washington by the University of Washington, with funding from the NOAA Climate and\nGlobal Change Program. Two additional stations at continental sites in the United States are also planned.\nAn automated tracking sunphotometer was operated throughout the year at Mauna Loa. The resulting data\nhave been analyzed for information on aerosol optical depth. This observational project has been unofficially\nrecognized as possibly the premiere effort of its kind in the world because of its unique location and reliable\nand fruitful data production. The upper tropospheric and stratospheric total aerosol burden is determined\nwith greater accuracy and precision than previously believed possible. Near background levels of aerosol\nwere observed in 1991 before the eruption of Mt. Pinatubo. The Pinatubo effects have been carefully\nmonitored through FY 92, and the data are being prepared for publication and have been shared with other\ninstitutions.\nPreparations were made to continue the CMDL aerosol optical depth monitoring project at key existing\nCMDL sites and new locations that are part of the CMDL initiative to study regional effects of radiatively\nactive anthropogenic aerosols.\nRadiation\nAn extensive comparison between measured and computed downward longwave irradiance (\"greenhouse\nradiation\") was carried out, and the results are being published. This project showed that, on the average\nover a year at four locations, the agreement between a commonly used radiometer and calculations using the\nLOWTRAN-7 radiative transfer model with routine radiosonde inputs was better than 1 W 2 far better\nthan the currently accepted uncertainties in either the model or observations would suggest.\nNet solar radiation measured at two of the CMDL observatories, Boulder and South Pole, were used in\nconjunction with satellite radiation budget observations, ERBE (Earth Radiation Budget Experiment), to\ndetermine the radiative effects of clouds. These data also assisted in developing algorithms for satellite\ndetermination of the clear and cloudy sky surface radiation values over vast unobserved areas of the globe.\nThis work was done in conjunction with the State University of New York, Stonybrook.\nGlobal lower tropospheric temperatures following the eruptions of Mt. Pinatubo and El Chichón were\ninvestigated using the NOAA TIROS-N microwave sounding unit (MSU) data set prepared and delivered\nby NASA and the University of Alabama, Huntsville. This information combined with the aerosol optical\ndepth data and total solar irradiance observations from the baseline observatories indicated the extent and\nmagnitude of the spread of the volcanoes' radiative effects as well as a general global cooling subsequent to\nthe eruptions. The CMDL data were of particular value because of the remote and latitudinally distributed\nlocations; the temperature data were of unique value because of their uniform global coverage and ready\navailability.\nThe Barrow surface albedo measurements continued to provide valuable information relative to the\nlong-term seasonal change in Arctic surface albedo as an indicator of climate change. This work was\n111","conducted with NASA/Langley and was expanded to include satellite observations of snow cover and\nsnowmelt dates.\nA curious relationship between the tropical stratospheric quasi-biennial oscillation (QBO) and the Mauna\nLoa atmospheric transmission annual cycle was identified and published. This finding provides a mechanism\nby which variations in solar energy at the tropopause can be weakly modulated by the QBO.\nPreliminary results of the radiative effects of Mt. Pinatubo on solar radiation observations at Mauna Loa\nwere examined in detail because of the unique observing conditions there. Highly accurate measurements\nof the solar irradiance variations as a function of aerosol optical depth were obtained and presented at the\nAmerican Geophysical Union (AGU) Chapman Conference on Volcanoes and Climate. Radiation measure-\nments at Boulder were enhanced following the eruption of Mt. Pinatubo to better monitor the cloud as it\nspread over the Northern Hemisphere.\nBasic surface radiation measurement programs were maintained throughout the year at seven CMDL\nlocations: Barrow, Boulder, Mauna Loa, Bermuda, Kwajalein, American Samoa, and South Pole. The data\nare intended for a variety of CMDL research efforts and as a contribution to an international effort, the Baseline\nSurface Radiation Network (BSRN). The first BSRN broadband radiometer instrumentation array was set\nup at the Department of Energy's Atmospheric Radiation Measurements (ARM) Program Cloud and\nRadiation Testbed (CART) site in northern Oklahoma. Plans for installing instrumentation at the main tower\nand at approximately 20 extended sites were formulated, and preparations to acquire instrumentation for\ninstallation at the CART site are in progress. The Oklahoma site is part of a larger and long-term effort to\nimprove knowledge of the radiative aspects of climate variability.\nCMDL participated in an international World Climate Research Program (WCRP) BSRN field experiment\nat Coffeyville, Kansas, from 13 November to 7 December 1991. The experiment was an intercomparison of\ninfrared instrumentation of the type generally used in the BSRN. Scientists from eight countries, representing\nmajor radiation laboratories worldwide, participated, and six different types of instruments were tested. The\nexperiment was combined with the First International Satellite Cloud Climatology Program (ISCCP)\nRegional Experiment (FIRE II) to take advantage of the high-precision infrared radiometry Spectral Radiation\nExperiment (SPECTRE) for an absolute comparison reference. The primary purpose was to establish the\nbest method and instrument for use in the WCRP BSRN network.\nOzone\nWorld Standard Dobson spectrophotometer no. 83, established and operated by CMDL, was again operated\nat Mauna Loa during the summer of 1992 to check its calibration and to obtain total ozone data for comparison\nwith ozone data obtained with the NASA Total Ozone Mapping Spectrophotometer (TOMS) and Solar\nBackscatter Ultraviolet (SBUV) satellite ozone spectrophotometer. Similar comparison observations made\nat Mauna Loa since 1978 have proven highly valuable in assessing the long-term calibration drifts of the\nsatellite instruments and have lent credence to recently published global ozone trends derived from the TOMS\ndata.\nTotal ozone observations were continued during 1991 at 15 Dobson instrument stations operated by\nCMDL, 4 of which are foreign cooperative stations. Observations were reestablished at a sixteenth station,\nTallahassee, Florida, following temporary suspension of the observing program there in 1989. At six of these\nstations, ozone vertical distribution measurements were made by the Umkehr method. Total ozone measu.\nments made during 1979-1991 indicate a downward trend in ozone of 3-4% at stations north of about 40°N\nlatitude and 2-3% at stations between 30° and 40°N latitude, but no trend in the tropics and subtropics.\nIn an ongoing program conducted to calibrate Dobson instruments of the World Meteorological Organi-\nzation (WMO) Global Ozone Observing System (GO3OS), four domestic and five foreign Dobson ozone\nspectrophotometers were calibrated in Boulder during FY 92. Additionally, intercalibrations were performed\n112","Climate Monitoring and Diagnostics Laboratory\nbetween Dobson instrument no. 83 and secondary standard Dobson instruments nos. 65 and 86. In a related\nactivity, intercalibrations were performed in Boulder between Dobson instrument no. 83 and a ground-based\nNASA Shuttle Solar Backscatter Ultraviolet (SSBUV) ozone instrument. This instrument is launched into\norbit by NASA for a few days each year, using the shuttle launch system, to calibrate operational NASA and\nNOAA satellite ozone instruments.\nWorking with other agency scientists, we derived improved Dobson instrument effective ozone absorption\ncoefficients based on new Bass-Paur laboratory values determined at NIST. The new coefficients yield total\nozone amounts 2.6% smaller than values derived from Vigroux-based coefficients that have been in use since\n1957. A recommendation was made to the WMO to begin using the improved coefficients in processing\nDobson instrument data beginning 1 January 1992. The recommendation was endorsed in December 1991\nby the WMO Executive Council Panel of Experts Working Group on Environmental Pollution and Atmos-\npheric Chemistry for implementation in the GO3OS.\nConsiderable progress has been achieved in a program begun in FY 92 to apply detailed final corrections\nto 357 station-years of NOAA total ozone data. The goals of this project are to optimize data quality for trend\nanalyses, satellite instrument ozone data validation, and research and to prepare the data for archival at the\nWMO World Ozone Data Center in Canada.\nUmkehr ozone profile observations, obtained at five northern middle-latitude stations, were corrected for\nstratospheric aerosols up to 1991. The profile observations were compared to the recently determined SBUV\nversion six ozone profile observations. The agreement was good, far surpassing previous comparisons that\nrevealed a serious degradation of the SBUV diffuser optics, that was causing a strong artificial downward\ntrend in ozone concentration. A new trend analysis of the data sets, starting in 1979, agreed well also. The\ntrend analysis indicated that.a downward trend in ozone appears at all levels, except near the ozone maximum\n(25 km) where no significant trend is seen. The Umkehr ozone profile data do not agree well with the\nStratospheric Aerosol and Gas Experiment (SAGE I) data, but do agree well with the SAGE II data. Upper\nstratospheric ozone trends calculated from the SAGE I and II data are significantly smaller than the trends\nderived from Umkehr data.\nSeventy vertical ozone profiles were obtained at South Pole using the digital ozonesonde system. Weekly\nsoundings were carried out during the austral summer and winter. The schedule was intensified to every\n3 days during the spring stratospheric \"ozone hole\" formation. Beginning in September 1991, significant\nozone reductions not seen in previous years were seen in the region near 28 km and in the low stratosphere\naround 12 km. The lower level depletion was clearly tied to the presence of volcanic aerosols from the\neruption of Mt. Hudson in southern Chile in August 1991. There is strong evidence that heterogeneous\nreactions on volcanic sulfate aerosols were responsible for the measured ozone losses. The causes of the\n50% reductions at the higher levels (28 km) were less apparent, although volcanic aerosols from Mt. Pinatubo\nmay be implicated. Ozonesonde measurements at Lauder, New Zealand, at Hilo, and at Boulder in 1991-1992\nwere compared with the 5-6 year record of soundings from those sites to look for possible effects on the\nozone distribution as a result of Mt. Pinatubo aerosols. Dramatic effects (as seen at South Pole) were not\napparent, although local reductions of a few percent in the region of the aerosol cloud are probable, which is\nconsistent with the expected depletion.\nThe CMDL surface ozone monitoring network has nine locations, primarily in areas remote from local\npollution effects. Results from this network show a strong tendency for a seasonal maximum in surface ozone\nin the Northern Hemisphere in the spring, whereas in the Southern Hemisphere a strong winter maximum\nprevails. In the high Arctic and tropics of the Northern Hemisphere, winter maxima are also seen.\n113","Water Vapor\nIn addition to the continuation of the 11-year monthly stratospheric water vapor vertical profile measure-\nments at Boulder, soundings were carried out as part of the Upper Atmospheric Research Satellite (UARS)\nCorrelative Measurements Program. In conjunction with UARS overpasses, soundings were made in\nBarstow, California, in Hilo, and in Lauder, New Zealand. As part of our ongoing study of polar stratospheric\ncloud process, stratospheric water vapor profiles were obtained at South Pole and McMurdo in Antarctica,\nand in northern Sweden.\nPlans FY 93\nAerosols\nDevelop instrumentation to measure aerosol absorption at South Pole and at the supplementary\nmonitoring stations.\nInstall instruments to measure aerosol chemistry and size at the four baseline stations. Develop new\nmultiwavelength nephelometers for use at the four baseline stations.\nEstablish a new network of aerosol monitoring stations to study the climatic effects of anthropogenic\naerosols. The new stations will complement the existing CMDL baseline stations, most of which are\nlocated in regions far removed from anthropogenic source areas. The new stations will measure key\nphysical, optical, and chemical properties of the particles at representative polluted and clean sites\nin continental and marine locations. Operations at the two marine sites are already (or soon to be)\nunder way. During FY 93, we plan to begin sampling at a clean continental site near Laramie, and\nat a polluted continental site at Bondville, Illinois.\nRadiation\nGather aerosol optical depth data from the new CMDL regional monitoring sites. This will involve\nestablishing on-site observing procedures, calibration logistics, data reduction, and quality control.\nThe effort relates to determining regional climatic effects of anthropogenic aerosols.\nContinue to analyze the 10-year aerosol optical depth record from Mauna Loa with emphasis on\nextremely clean \"background\" periods and volcanic effects. Improvements in the data reduction\nprocedures will be investigated which account for the aerosol vertical distribution.\nContinue to upgrade existing surface radiation budget monitoring projects at the CMDL global\nbackground sites with emphasis on enhanced calibration integrity, dome condensation elimination,\ndiffuse solar irradiance, and data acquisition hardware. Data from the five sites will be submitted to\nthe BSRN data archival center at Zurich, Switzerland, for review and approval by the BSRN\nparticipants.\nContinue examining the evolving global mean lower tropospheric temperatures relative to recent\nvolcanic events and oceanic surface temperature anomalies.\nPending new funding, incorprate upgrades and operational enhancements into the Mauna Loa\nsunphotometer calibration capability. The most needed are data acquisition and automated dome\ncontroller hardware. New continuous output, single-channel sunphotometers need to be built. The\n114","Climate Monitoring and Diagnostics Laboratory\nMauna Loa sunphotometer calibration capability will help support the new CMDL regional aerosol\nnetwork.\nFinalize and report the analysis of the measurements obtained at the FIRE II broadband radiometer\nintercomparison. Some preliminary results have become available for a first look by the participants.\nContinue calculations of stratospheric aerosol corrections to Umkehr ozone profile observations.\nComparisons of Umkehr observations with satellite observations from SBUV and SAGE will be\ndone.\nOzone\nCompare Dobson instrument no. 83 and satellite total ozone observations again at Mauna Loa during\nthe summer of 1993.\nContinue ozone observations at 16 domestic and foreign stations.\nCalibrate additional foreign Dobson instruments with emphasis on instruments from southeast Asia.\nCalibrate one or more ground-based SBUV instruments at the Ball Aerospace Systems Corporation\nin Boulder.\nContinue final total ozone data processing and archiving.\nStudy the effects of Mt. Pinatubo aerosols on the ozone layer at both subtropical and high latitudes\nwith particular emphasis on the Antarctic.\nCarry out intensive ozonesonde measurements at Bermuda as part of the North Atlantic Regional\nExperiment (NARE) emphasizing tropospheric ozone profiles.\nEstablish a second surface ozone monitoring site and carry out ozonesonde measurements in Iceland\nas part of the NARE summer 1993 campaign.\nTest and compare the new Umkehr ozone profile inversion algorithm with other ozone profilers such\nas the SBUV, SAGE, and ozonesondes.\nWater Vapor\nContinue UARS correlative water vapor measurements in Hawaii, New Zealand, and McMurdo, and\ncontinue monthly soundings in Boulder.\nMake approximately 15 water vapor and ozone soundings in the western tropical Pacific in March\n1993 as part of the Central Equatorial Pacific Experiment (CEPEX).\nCarry out a laboratory water vapor intercomparison between the CMDL frostpoint hygrometer and\nthe Aeronomy Laboratory ER-2 Lyman-alpha hygrometer.\n115","CLIMATE RESEARCH\nAccomplishments FY 92\nData Management and Data Set Development\nThe Climate Research Data Center, the result of a Climate and Global Change initiative now in its second\nyear, has continued the development of a versatile software environment called CRDtools for simplified\nacquisition, preliminary analysis, and visualization of climate data sets for researchers throughout the nation.\nNew features added during FY 92 include a point-and-click capability to perform Hovmöller analyses, to\ndisplay scatter plots, and to extract and manipulate data sets stored in netCDF, a widely used Common Data\nFormat developed by University Corporation for Atmospheric Research (UCAR). Other new features include\nan easy-to-use file finder and a sophisticated tool for generating highly tailored presentation graphics. The\ndata archive component of the Climate Research Data Center has added 9 years of monthly mean European\nCentre for Medium-Range Weather Forecasting (ECMWF) analyses and the Climate Analysis Center's\n(CAC) Climate Diagnostic Data Base, a 12-year monthly mean set of National Meteorological Center (NMC)\nanalyses with many supplemental derived fields.\nDuring FY 92, important milestones were reached in the evaluation and improvement of the Comprehen-\nsive Ocean-Atmosphere Data Set (COADS). An International COADS Workshop was held in Boulder in\nJanuary 1992. The workshop was organized to provide a forum for user feedback and evaluation of the\nCOADS and to help guide future development of the data set.\nThe principal findings and recommendations dealt with restructuring of the data base and improvements\nin data quality control procedures. It is clear that improved procedures are needed for trimming outliers and\nidentifying mislocated data. Efforts to develop such improved data quality control techniques have been\nunder way at Climate Research Division (CRD), Cooperative Institute for Research in Environmental\nSciences (CIRES), National Center for Atmospheric Research (NCAR), and National Climatic Data Center\n(NCDC) for the past few years and are continuing. Efforts at providing homogenized versions of selected\nCOADS variables have also been under way within NOAA and at other organizations both in the United\nStates and abroad. These efforts will continue and expand in future years.\nA high-quality station temperature and precipitation data set with daily and monthly time resolution for\nglobal land areas has been developed under a cooperative project with NCDC in Asheville, and the CAC in\nWashington, D.C. The project, known as the Global Climate Perspectives System (GCPS), has as its main\ngoals to develop a comprehensive archive of climate and climate-related data sets that are useful for providing\ninformation about climate variations worldwide as well as regional-scale assessments, and to develop an\nintegrated system of data analysis tools that include statistical analysis software, graphical interfaces, database\nmanagement and common hardware (for interoperability and optimum access), and communication capa-\nbilities. This data set should prove very valuable for studies of climatic change and variability, for improved\nregional climatologies of surface temperature and precipitation, and for a variety of other climatological\napplications.\nClimate Diagnostic Research\nA detailed diagnostic study was completed on the dynamics of large-scale cyclogenesis over the North\nPacific Ocean. The results indicated that the primary mechanism was a large-scale barotropic-baroclinic\ninstability of the wintertime climatological mean flow. A second diagnostic study examined processes\ncontributing to the formation and maintenance of the 1988 summer heat wave and drought. The results of\n116","Climate Monitoring and Diagnostics Laboratory\nthis work indicated that both dynamical forcing from a remote source and anomalous boundary conditions\nin the drought region appeared to contribute to the development and maintenance of the heat wave and\ndrought, with the former being particularly prominent at early stages and the latter assuming increased\nimportance at later stages. Collaborative studies have been initiated between CRD and CAC to examine the\nsensitivity of extratropical, dynamical, extended range predictions to changes in tropical flow and heating\nfields.\nAtmospheric diabatic heating is a crucial component of the climate system, but it has been extremely\ndifficult to produce realistic estimates of this quantity from data. Recent studies examined the sensitivity of\nthe calculations of heating to a variety of physical and numerical approximations in the calculations. Data\nfrom several major operational centers and research organizations were used in this analysis to understand\nthe range of uncertainty. A method for reducing the range of uncertainty and generating a more reliable\nestimate of heating was developed and is being improved.\nData from the NOAA polar-orbiting satellites over the last 9 years were compiled and examined for\ndetermining the atmospheric water vapor content. These data have been particularly useful for monitoring\nwater vapor in the upper troposphere by analyzing the brightness temperatures of the atmosphere near the\ncenter of the water vapor band near 6.5 um. Monthly mean images of these data appear highly correlated\nwith the large-scale overturning circulations in the tropics and subtropics. Analysis of the time-space variance\nof these data showed that interannual changes in water vapor are linked to the large-scale circulation changes\nduring ENSO. These studies are continuing as part of the Global Energy and Water Cycle Experiment\n(GEWEX) Water Vapor Project (GVaP). During the past year, GVaP has been endorsed by the GEWEX\nScience Steering Group and the WCRP.\nStudies also continued on the application of satellite-derived sea-surface temperatures (SST) in global\nclimate monitoring. Evaluations of a decade of satellite SSTs versus COADS SSTs were conducted and\npresented. The results show that the satellite SSTs continue to be plagued by large biases caused by the large\nvolcanic aerosol events of the last 10 years, particularly El Chichon and Mt. Pinatubo. Immediately after the\nMt. Pinatubo eruptions, biases of greater than 5°C were found in the tropics on a zonally averaged monthly\nmean basis.\nPlans FY 93\nData Management and Data Set Development\nEnhance CRDtools software and expand the data archive with new data sets provided in netCDF.\nThe ability to extract data sets in WMO's Gridded Binary (GRIB) format will also be developed.\nAnalysis and visualization tools to be added include principal component analysis, interactive pan\nand zoom, histograms, and variable-speed animations. Many refinements will be added in response\nto end-user feedback. New data sets will include twice daily (versus monthly) ECMWF and NMC\nanalyses and an updated and expanded version of COADS.\nUpdate COADS by merging many new data sets and addressing problems identified with different\nobserving platform types. In addition, it appears highly desirable to develop summary products with\nhigher spatial and temporal resolution for some variables, most likely for the period since about 1957.\nFor addressing inhomogeneities in the basic variables, it is essential that researchers have access to\nall the individual observations, which implies mass storage requirements of 10 GB and relatively\nfast access protocols. Update plans include a complete set of statistics for 1980-1991, scheduled for\nrelease in late 1992, and a major update for the total period from 1854 (or earlier) to date, by the\nmid-1990s. A general update strategy was described for continued annual updates and periodic major\nupdates.\n117","Study natural climate variability and improve diagnostic and analysis tools as part of the GCPS\nproject. In particular, we propose to use GCPS for three main tasks: (1) updating and improving the\nexisting data bases, analysis tools, and visualization software; (2) performing diagnostic studies of\npast climatic variability (analysis of natural climate variability); and (3) assessing of ongoing (near\nreal-time) climate anomalies of regional or global significance.\nClimate Diagnostic Research\nPerform model forecast experiments to investigate processes important to dynamical extended range\nweather forecasting and to the prediction of short-term climate variability on time scales ranging\nfrom a few weeks to a season. These studies will focus on the sensitivity of model predictions to\nchanges in tropical flow and heating fields and to latent heat release at midlatitudes. These are areas\nwhere model errors are often large and where prospects for future model improvements appear\nreasonable. Part of this work will be performed in collaboration with scientists at CAC.\nStudy changes in atmospheric heating from 1985 to 1991 using the techniques developed this past\nyear. Data sets from NMC and ECMRWF will be used. Heating estimates from the two data sets\nwill be compared. Relationships between the changes in heating and changes in the atmospheric\ncirculations will be investigated.\nContinue work on the implementation plan for the pilot phase of GVaP. Different satellite-derived\nproducts of water vapor will be examined and compared. We also hope to begin work with the\nEuropean Space Agency to examine data from a new satellite that should provide improved estimates\nof SST regardless of atmospheric aerosol content.\nSPECIAL PROJECTS AND OBSERVATORY PROGRAMS\nAccomplishments FY 92\nThe Special Projects Group conducted the month-long (25 March-25 April 1992) AGASP-IV field\nexperiment out of Anchorage, Alaska. Aerosols, trace gases, and solar radiation measurements of the Arctic\nHaze phenomenon and lead aerosol plumes in the Beaufort Sea region were made using the NOAA WP-3D\nOrion research aircraft (P-3).\nLow altitude fly-bys of the Point Barrow baseline station were conducted during AGASP-IV to test the\nrepresentativeness of surface measurements as related to vertical profiles of the same gas and aerosol species\nmeasured by the P-3.\nThe concurrent Leads Experiment (LEADEX) also used the P-3 to measure heat, moisture, and momentum\nfluxes over leads in the pack ice. Boundary layer winds over the ice were studied to observe their effect on\nlead formation. A detailed study of the barrier winds along the North Slope of the Brook Range was performed\nto describe the mesoscale flow influencing local transport in the region.\nInitial processing has been performed on the AGASP-IV/LEADEX data set. This included transferring\nand reformatting the data from P-3 aircraft data tapes to IBM/PC diskettes. Software was written to facilitate\nthe extraction and further processing of any of hundreds of parameters from the data set.\nThe analysis of Arctic radiosonde data sets continued to determine if \"greenhouse warming\" occurred in\nthe Arctic over the period 1957-1986. These data were incorporated into the Historical Arctic Rawinsonde\n118","Climate Monitoring and Diagnostics Laboratory\nArchive. Two manuscripts on temperature trends in the Arctic were prepared and submitted to scientific\njournals.\nThe analysis and digitization of all Antarctic surface ozone records was completed, including 6 years of\ncontinuous strip-chart ozone data from McMurdo station.\nThe collection and archival of balloon-borne, cascade impactor stratospheric aerosol samples of the Mt.\nPinatubo volcanic ash cloud over the Colorado-Wyoming region continued. Analysis of some of these\nsamples was begun.\nAerosol samples from the burning Kuwaiti oil field collected by group personnel during the Kuwait Oil\nFire/Smoke Experiment (KOFSE) were analyzed for soot carbon and trace element concentrations. Initial\ndata analysis was performed.\nA series of research flights was conducted using the NOAA King Air research aircraft to calibrate the\nNOAA airborne aethalometer under rapid ascent and descent conditions as a component of an aerosol\ncharacterization program supported by White Sands Missile Range.\nWind and temperature sensors were installed at six levels on the 40-m tower at Mauna Loa to study the\ntransition period between upslope and downslope flows and the separation in the nocturnal boundary layer\nflow. The data can be displayed in Boulder through a computer modem connection.\nPreparations were begun to conduct an airborne calibration of the Mauna Loa baseline station, similar to\nthat performed in April 1992 for Point Barrow.\nFunding was acquired by group personnel to participate in the FY 93 NASA SPADE. Preliminary\nlaboratory studies have been started to characterize the collection efficiency of our aerosol sampler for\nparticles of various sizes.\nFunding from the National Science Foundation (NSF) was acquired to conduct an investigation of\naircraft-mounted aerosol inlets and to construct \"next generation\" inlets that efficiently collect atmospheric\nparticles. These inlets will be built SO that they can easily be incorporated into existing structures on the\nNOAA P-3 and King Air aircraft.\nCooperative research programs continued as part of the broader research program at the four CMDL\nbaseline stations and as an integral part of CMDL's contact with the broader atmospheric research community\nwithin the United States as well as with the international community. These cooperative projects complement\nin-house CMDL monitoring and research activities. Areas of investigation include identifying and under-\nstanding tropospheric chemical reactions that affect the concentrations and transformation of greenhouse\ngases in the background atmosphere, locating and quantifying continental and oceanic sources and sinks of\ngreenhouse gases, measuring carbon isotopes to identify the biogenic and oceanic fractions of the atmospheric\ncarbon budget, and taking aerosol measurements to identify major long-range transports of anthropogenic\nand biogenic aerosols. These cooperative projects are supported by universities, NSF, other government\nagencies, and foreign countries such as the University of Rome; University of Wyoming; Scripps Institution\nof Oceanography; Department of Energy Environmental Measurements Laboratory; Commonwealth Scien-\ntific and Industrial Research Organization (CSIRO), Australia; NCAR; University of Washington; University\nof Tokyo; Alaska Soil Conservation Service; University of California; Colorado State University; University\nof Rhode Island; University of Virginia; Desert Research Institute; University of Nevada Systems; University\nof Denver; Australian Nuclear Science and Technology Organization; Woods Hole Oceanographic Institution;\nUniversity of Hawaii; and the University of Miami.\nPlans FY 93\nContinue the processing, analysis, and interpretation of the extensive AGASP-IV/LEADEX data set.\nPersonnel from the group will be responsible for assembling all aerosol, trace gas, radiometric, and\n119","meteorological data from these projects. Seven papers discussing these data will be prepared for\npublication.\nObtain funding and continue planning and preparations for the Mauna Loa calibration program in\nFY 94. This program, called the Pacific Dust Experiment (PACDEX), will involve scientists from\nJapan, China, Korea, and the United States, and will include a NOAA WP-3D research aircraft and\ntwo ships (Chinese and Korean).\nContinue the data analysis and interpretation of KOFSE aerosol samples from the Persian Gulf.\nContinue programs of cooperation with universities, research institutions, and other government\nagencies at the CMDL baseline observatories.\nContinue planning and begin construction of the Network for the Detection of Stratospheric Change\n(NDSC) observatory on Mauna Loa for long-term monitoring of the stratosphere to detect and\nunderstand stratospheric ozone destruction.\nImprove data collection strategy and procedures at Mauna Loa. Instrument signals will be collected\ninto one data stream, transmitted to the Hilo office, and monitored daily. These real-time data will\nthen be interfaced to Internet for direct readout in Boulder. Equipment malfunctions will be detected\nas they occur and repairs planned before driving to the mountain.\nParticipate in SPADE-1 and analyze stratospheric aerosol samples from the mission.\nBegin laboratory and wind tunnel studies of prototype inlet designs for the NSF Inlets Study. Begin\nfabrication of the most promising designs for testing on aircraft.\n120","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nAIR RESOURCES LABORATORY\nSilver Spring, Maryland\n(301) 713-0684\nBruce B. Hicks, Director\nAir Resources Laboratory (ARL) research is geared to the needs of NOAA and other federal agencies with\nrelated missions. These other agencies include the Departments of Energy (DOE), Interior, and Defense, the\nNuclear Regulatory Commission (NRC), the Federal Aviation Administration (FAA), and the Environmental\nProtection Agency (EPA). In addition, agencies from several states draw on ARL expertise. The general\nareas of study relate to air quality and climate, and research focuses on turbulence and diffusion in the\natmosphere, global transport of pollutants, meteorology of air pollution, air-surface exchange (including both\nwet and dry deposition), and global climate change. The work includes observational and theoretical studies\nas well as instrument and model development. ARL is also the official government source for information\non atmospheric dispersion to guide many emergency response activities. ARL consists of a Headquarters\nDivision in Silver Spring, Maryland; the Atmospheric Sciences Modeling Division (ASMD) in Research\nTriangle Park, North Carolina; the Atmospheric Turbulence and Diffusion Division (ATDD) in Oak Ridge,\nTennessee; the Field Research Division (FRD) in Idaho Falls, Idaho; and the Aerosol Research Section (ARS)\nin Boulder, Colorado.\nThe Clean Air Act Amendments of 1990 affect several ARL divisions. ASMD is participating in the EPA\nClean Air Status and Trends Network (CASTNET) program to implement a national monitoring network to\nassess changes in air quality and acidic/toxic deposition resulting from emission changes. Several ARL\ngroups, together with the Aeronomy and Wave Propagation Laboratories, are joining in the Atmospheric\nIntegrated Research Monitoring Network (AIRMoN) to measure the consequences of emissions changes\nmore rapidly than is possible using standard monitoring procedures. During FY 92, strong linkages were\nformed between CASTNET and AIRMON, and the two programs are now proceeding in parallel.\n121","HEADQUARTERS DIVISION\nAccomplishments FY 92\nARL leads research on the Atmospheric Nutrient Input to Coastal Areas (ANICA) component of NOAA's\nCoastal Ocean Program. In FY 92, ANICA was largely a continuation of the low-level preparatory efforts\ninitiated in FY 91. Collection and quality assurance of precipitation chemistry data from the Chesapeake\nBay catchment area is now nearing completion, and efforts to sort wet deposition data according to event\nprecipitation rates and amounts have begun. Dry deposition monitoring equipment was set up at the Wye\nResearch Institute on Maryland's eastern shore in late September. Preliminary U.S. Geological Survey\n(USGS) land-use classifications for the United States, using NOAA-11 satellite imagery, are being used as\ninput for detailed atmospheric flow-field models of the Chesapeake Bay catchment area, later to be used as\na basis for computing dry as well as wet deposition rates. The earlier plan to instrument upwind and downwind\nsites to monitor the stability regime over the Bay surface was changed in favor of using an instrumented buoy\noperated by the University of Maryland Center for Environmental and Estuarine Studies.\nAs part of the University of Virginia Global Precipitation Chemistry Program, the first measurements of\nchlorine gas in the marine boundary layer were made; these revealed significant concentrations and a\ndiurnal cycle.\nAIRMoN\nIn FY 91, the AIRMON concept was developed to rapidly detect air quality and deposition changes that\nresult from emissions changes. The three main components of AIRMON are air quality, wet deposition, and\ndry deposition. In FY 92, the AIRMON concept was further refined through a series of position papers\nconcerning such issues as site selection, the development of urban monitoring studies, and the importance of\nfield measurements in the precipitation chemistry monitoring network. Field operations centered on\nstabilizing and integrating existing wet and dry deposition networks into a comprehensive program and on\ninstituting a long-term relationship with the National Atmospheric Deposition Program (a multiagency\nactivity coordinated by Colorado State University) to ensure the continuation of high-quality precipitation\nchemistry analyses following the demise of the only national short-term sampling program (previously known\nas the MAP3S program, sponsored by DOE).\nAir Quality and Dispersion\nCalculations of sulfate wet deposition and air concentrations for the entire year of 1989 were completed\nusing the Hybrid Single Particle Lagrangian Integrated Trajectories (HY-SPLIT) transport and dispersion\nmodel with a nonlinear chemistry module. Two sets of calculations were performed. One used the Nested\nGrid Model (NGM) predicted precipitation fields and the other used measured precipitation values in\ncomputing wet deposition. In general, the NGM predictions were an adequate substitute for the measured\ndata when seasonal (or longer) averages are desired.\nTo add detail necessary to address the dry deposition component, the Colorado State University Regional\nAtmospheric Modeling System (RAMS) was configured to run operationally, using the current National\nMeteorological Center (NMC) forecast as meteorological input.\n122","Air Resources Laboratory\nGlobal Climate Change\nThe ARL record of global tropospheric and low-stratospheric temperatures now extends from 1958 through\nthe summer of 1992. Tropospheric temperatures for the first three seasons of 1992 were the coldest since\n1976. After adjustment for the influence of the El Niño-Southern Oscillation, the first three seasons of 1992\nwere found to be the coldest since 1964 (the year after the Agung eruption). The sudden drop in global\ntemperature is undoubtedly related to the eruption of Mt. Pinatubo in June 1991. The warming of the lower\nstratosphere following the Mt. Pinatubo eruption appears to be greater than that after the eruption of El\nChichón, which in turn was greater than that after Mt. Agung erupted.\nGlobal total ozone records were updated through 1991. In the global average, there was 1.4% more ozone\nin 1991 than in 1990. There was a decrease in global ozone again at the end of 1991, perhaps partly related\nto the Pinatubo eruption.\nStudies of the effects of humidity instrument changes on the climate record revealed significant effects\nworldwide. There are also inhomogeneities in the spatial and temporal moisture patterns, caused by\ndifferences in the way nations convert humidity signals to dewpoint. After correction, the annual cycles of\nhumidity suggest that five regimes can be identified, depending on the annual ranges and phase relations of\ntemperature and moisture. The relation between surface temperature and total column water vapor was\nquantified over a wider range of conditions than is possible from satellites. The study generally confirmed\nequations from these studies but found they did not apply well outside the temperature range for which they\nwere derived. The relation between surface temperature and column water vapor is not good at high\ntemperatures, and interannual variations in these quantities are not well correlated in the tropics.\nEmergency Response and Preparedness\nA trajectory accuracy study was completed by comparing satellite observations of the Kuwait oil fires\nsmoke plume and predictions using coarse and fine grid model analysis fields. Relative trajectory errors\naveraged about 14% for the coarse and 10% for the fine grid data. Dispersion prediction methods were used\nto refine earlier assessments of the possible consequences of a reactor accident in Cuba. Using the latest\narchived meteorological data at ARL and the HY-SPLIT model, with a coupled statistical program, a revised\nanalysis was completed.\nThe Volcanic Ash Forecast Transport and Dispersion (VAFTAD) model was completed. ARL ran the\nmodel for three eruptions, Mt. Pinatubo, Mt. Bogoslof, and Mt. Spurr. The VAFTAD model was used on a\nfairly continuous basis following the late June eruption of Mt. Spurr, permitting some evaluation of the\npredictions by comparison against satellite and other observations. Arevision of multiagency procedures for\nvolcanic hazard alerts is being considered, and will probably include a strong role for ARL, which now\nprovides almost all the models used for related purposes in the United States.\nPlans FY 93\nA modeling study will be conducted to compute ground-level air concentrations, from pollutants emitted\nfrom the Kuwaiti oil fires. Lagrangian wet deposition modeling efforts will be expanded to incorporate\nnitrogen chemistry and more detailed spatial structure by incorporating major point source plumes within\ncertain regions. RAMS research efforts will be directed at improving surface boundary conditions and\napplying the model results more directly to air quality simulations.\nEvaluation of the VAFTAD model will be completed, and an operational version of the model will be\ntransferred to NMC. In cooperation with the National Weather Service, ARL will provide forecast support\n123","of atmospheric pollution emergencies, through the World Meteorological Organization (WMO), in terms of\nthe transport and dispersion of pollutants that may cross international boundaries. A radiological dose code\nwill be implemented in conjunction with the dispersion forecasts.\nThe focus of ANICA will be on (1) measuring atmospheric nitrogen fluxes to two calibrated catchment\nareas (Wye River and Edgewater) within the Chesapeake Bay watershed, (2) completing assembly of wet\ndeposition data for the watershed, (3) establishing an additional daily wet deposition monitoring station at\nWye River, (4) continuing studies of dry deposition of atmospheric nitrogen compounds to the water surface\nof the Chesapeake Bay using one or more Chesapeake Bay Observing Systems (CBOS) buoys, (5) initiating\nair chemistry/nitrogen speciation investigations, and (6) establishing an eddy correlation station within\nthe watershed.\nPosition papers on AIRMON will continue to be refined, additional field stations will be instituted as\nfunding allows, and methods will be developed to automate the generation of modeled source-receptor\nrelationships in conjunction with wet and dry measurements. Other ARL divisions will become more actively\ninvolved. In particular, the dry deposition research network operated by the ATDD in Oak Ridge, will be\nintegrated with the AIRMON program.\nThe Global Precipitation Chemistry Program will continue routine monitoring at its five remote locations,\ncontinue research on chlorine in the troposphere, and conduct additional studies on the flux of nitrogen and\nsulfur compounds to the Atlantic Ocean.\nTemperature, cloudiness, sunshine, and ozone records will be continued, with expanded attention to the\npossible roles of volcanism. Data from the global radiosonde network will be refined, and work will begin\non a global water vapor climatology.\nATMOSPHERIC TURBULENCE AND DIFFUSION DIVISION\nAccomplishments FY 92\nAir-Surface Exchange\nThe aircraft-mounted Mobile Flux Platform (MFP) was used in the DOE Atmospheric Radiation Meas-\nurements (ARM) Program at Boardman, Oregon, during June 1992. The MFP combines new atmospheric\nsensing, positioning technology, and analysis methods to derive accurate turbulent flux information. Over\n180 hours of airborne MFP data have now been obtained in the two ARM (1991 and 1992) collaborative\nstudies to evaluate turbulent fluxes of momentum, heat, water vapor, and CO2 over various species of\nvegetation and over an adjacent desert. During the 1992 study, surface fluxes were also measured using eddy\ncorrelation equipment on towers operated by ATDD.\nA new instrument for fast-response measurements of methane was used to measure methane fluxes from\na landfill in the Oak Ridge area. The sensitivity and response of this open-path system seem adequate to\nallow similar measurements over landfills, bogs, rice paddies, and other potential sources of methane, helping\nto establish methane's global budget.\nAn experiment was conducted at the Oak Ridge National Laboratory Walker Branch Watershed to study\nemissions of isoprene from leaves and plant canopies. The study also included scientists from other ARL\ngroups, the National Center for Atmospheric Research (NCAR), and Washington State University. A\nsimultaneous study determined exchange rates for ozone, radon, and peroxides. Some exploratory measure-\nments of mercury gradients were also conducted. Daytime 1-2 h integrated mercury vapor samples were\ntaken above the forest, with simultaneous measurements of water vapor and CO2 gradients and fluxes,\n124","Air Resources Laboratory\npermitting the use of the modified Bowen-ratio method to interpret the gradients of mercury. Gradient\nmeasurements were also made near the bottom of the canopy to determine whether the forest floor acts as a\nsource or sink of mercury vapor.\nAnalyses of ATDD's airborne and tower data from the 1990 Rural Oxidants in a Southern Environment\n(ROSE) study were completed. Aircraft and tower eddy fluxes agreed well, and ozone profiles made using\na tethered kytoon revealed a strong diurnal signal that extended throughout the entire mixed layer. In June,\nthe ATDD airplane and tower eddy flux systems were used in the ROSE-92 study, led by the Aeronomy\nLaboratory.\nAleaf-to-canopy photosynthesis and evaporation model was developed and tested against data. The model\nshows promise for examining the transport of gases over incomplete canopies and trace gases that exhibit\nbidirectional exchange characteristics. The model is expected to be useful in parameterizing fluxes for use\nin larger-scale models.\nThe ATDD Lagrangian random-walk canopy model was applied to sulfur dioxide and nitric acid deposition\nover canopies. Model computations of deposition rates and concentration profiles agree well with data.\nTOGA COARE\nATDD, in collaboration with New Zealand's National Institute for Water and Atmospheric Research\n(NIWAR), developed plans for air-sea momentum, heat, and water vapor flux measurements in support of\nthe Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE)\nstudy in the tropical western Pacific Ocean. High-precision measurements will be made, using the MFP on\na small (12-m length) ocean-going sailboat operating with furled sails to minimize flow obstruction and\ndistortion. Two MFP systems and a spare were constructed.\nDry Deposition\nThe annual site visit and refurbishment of the ATDD Dry Deposition Inferential Method (DDIM)\nmonitoring stations was conducted. New sites near Phoenix, Arizona, and Burlington, Vermont, became\noperational. The CORE/satellite network continued to monitor any changes in dry deposition that may result\nfrom new emission controls. During FY 92, more process-level modeling was incorporated into the\nair/surface exchange parameterizations for the major pollutants of interest. A new dry deposition CORE/sat-\nellite station was installed in Wye, Maryland, near the Chesapeake Bay (as part of ANICA).\nSeveral years of chemical concentration records were analyzed to assess the use of weekly average\nconcentrations in the ATDD-developed inferential approach for estimating dry deposition of sulfur dioxide.\nSummertime correlations between measured concentrations and inferred deposition velocities for SO2 in Oak\nRidge cause about a 20% underestimate of inferred annual SO2 deposition.\nATDD completed the Large Area Deposition Model for EPA. The model estimates the spatially variable\ndry deposition velocity of a pollutant by accounting for local variations in topography and vegetation, SO that\ndry deposition can be calculated using observed or modeled concentration fields.\nTurbulence and Diffusion\nA new theoretical treatment of the diffusion of continuous plumes as a function of downwind distance and\nsampling time was developed. In addition, wavelet transforms were used to decompose the turbulent motion\nof a single fluid particle into coefficients corresponding to different time scales. A wavelet treatment of\n125","diffusion was then developed. Turbulence and diffusion in the stable planetary boundary layer (PBL) are\nbeing studied extensively. Because these are characteristically intermittent and inhomogeneous, the appli-\ncation of standard air quality models can be highly uncertain at night. Sources of intermittent turbulence\ninclude terrain-generated flow perturbations, drainage winds, gravity waves, and shear instabilities. ATDD\nhas taken an active role in improving the understanding (and, eventually, developing parameterizations) of\nstable PBL turbulence and diffusion. An initial study was completed of an episode during the 1990\nAtmospheric Studies in Complex Terrain (ASCOT) Waves and Turbulence Experiment of wave and\nturbulence interaction. ATDD and Argonne National Laboratory scientists are collaborating in a related study\nof intermittent breakdowns of the nocturnal stable boundary layer at a site in northern Illinois.\nComplex Terrain\nData from the 1990 Oak Ridge meteorological site survey were used to study the spatial variability of the\nwind in the Tennessee River valley and its response to winds aloft. The horizontal variability of the in-valley\nwinds was also evaluated. The same region was selected to test the LINCOM wind field model (the linear\ncomplex terrain model developed at Riso National Laboratory, Denmark) as a potential improvement over\nwind field interpolation schemes. New two- and three-dimensional Lagrangian stochastic dispersion models\n(LSDM) are being developed. Model results are being tested against ASCOT tracer data.\nEmergency Response and Preparedness\nAssistance was provided to DOE in designing a meteorological tower network to be used near the proposed\nYucca Mountain high-level radioactive waste repository in Nevada.\nFollowing a review of the dispersion models in use at the National Aeronautics and Space Administration\n(NASA) Kennedy Space Center, an ARL team designed a comprehensive experimental program to improve\nthe existing emergency response systems.\nWieliczka Salt Mine\nUnder the auspices of NOAA, the National Park Service, and the Maria Sklodowska-Curie Joint Fund II,\nATDD led a group of five U.S. scientists in exploratory studies within the endangered Wieliczka Salt Mine\nWorld Heritage site near Krakow, Poland, in collaboration with a team from the Polish Academy of Sciences.\nThe goal was to determine the likely sources of moisture in the mine that are causing the centuries-old\nmonuments and carvings in the salt to deteriorate.\nPlans FY 93\nATDD will design and participate in a field study of cold air drainage and pooling near DOE's proposed\nYucca Mountain repository.\nData will continue to be collected in the Wieliczka Salt Mine. The data will be analyzed by the U.S. and\nPolish teams to identify the moisture sources and to suggest appropriate remedies.\nATDD will continue developments related to several modeling activities, concerning (a) the use of wavelet\ntransforms to address dispersion in situations of nonstationary and intermittent turbulence, (b) methods for\n126","Air Resources Laboratory\naccounting for the effects of spatial variability in the wind field, and (c) the use of two-dimensional and\nthree-dimensional LSDMs for complex terrain. Work will continue on the Danish LINCOM flow field model.\nStability and wind direction shear effects will be added. Emphasis on studies of the stable PBL will grow,\nfocusing on interactions between gravity waves and turbulence using data from Oak Ridge, eastern Wyoming,\nand northern Illinois. The main goal will be to correlate nocturnal episodes of turbulence with the presence\nof gravity waves. Collaboration with Argonne National Laboratory on the study of intermittent breakdowns\nof the stable boundary layer will continue.\nThe initial SANA experiment (Sanierung der Atmosphäre über den neuen Bundesländern; a multiyear\nprogram monitoring the expected decline of ambient air pollution in what used to be East Germany) will be\ncarried out during 1993, near Leipzig, Germany. ATDD will measure turbulent fluxes of O3, NO2, and SO2,\nas well as sensible and latent heat, to test the latest parameterization of the DDIM model.\nDuring January and February 1993, ATDD will participate in the multination TOGA COARE experiment.\nHigh-resolution momentum, heat, and water vapor fluxes will be measured from a sailboat over the warm\npool region of the tropical western Pacific Ocean.\nATDD will collaborate with the Universita della Tuscia, Italy, to develop a mechanistic, environmentally\ndriven model for carbon dioxide, water vapor, and sensible heat exchange over a temperate forest. The model\nwill be tested against flux data collected above an Italian forest.\nATMOSPHERIC SCIENCES MODELING DIVISION\nAccomplishments FY 92\nField Studies\nAn easily transportable system to measure the fluxes of ozone, sulfur, and several nitrogen species at sites\nof the National Dry Deposition Network (NDDN) was built. When the system is deployed, the measurements\nwill be monitored remotely at the central facility at Research Triangle Park for analysis and quality assurance.\nThe fluxes will be determined using eddy correlation and profile techniques.\nPreliminary analyses were made of recently acquired data from the Stagnation Model Analysis Program\n(STAGMAP) diffusion study in Medford, Oregon, from January to February 1991, which obtained mete-\norological measurements and tracer concentrations during extremely low wind conditions. The largest\nconcentrations were measured during clear, extremely stable conditions.\nModeling Studies\nASMD evaluation studies of the Regional Acid Deposition Model (RADM) using aircraft data from the\nAcid Models Operational and Diagnostic Evaluation Study (Acid-MODES) continue. The study found\nimportant subgrid scale contribution to model bias, particularly for ozone, in the vicinity of the major point\nsource utility region. The predicted mixture of nitrogen oxides and volatile organic compounds (VOC) in\nthe source regions in effect ignores the complex photooxidant chemistry associated with power plant plumes,\nand as a result important sources of model bias are introduced. As a consequence, research on formulating\nelevated point source plumes within a Eulerian grid model framework was initiated.\n127","A preliminary version of the Regional Particulate Model (RPM), which incorporates advanced state-of-\nscience aerosol chemistry and dynamics modules, has been undergoing testing. A visibility module is under\ndevelopment as a postprocessor to permit the RPM to be used in visibility and acid aerosol studies.\nA detailed report on the model sensitivity study of the Regional Oxidant Model to biogenic hydrocarbon\nemissions will soon be available. Ozone formation was found to be significantly influenced by biogenic\nemissions, and the extent of influence varied spatially over the northeastern United States. The study implies\na greater role for ambient NO in forming ozone.\nDevelopment of Prototype-Alpha as the initial system of the next generation of Eulerian grid, emissions-\nbased modeling system (MODELS-3) was begun. When completed, Prototype-Alpha will provide a means\nto test existing massively parallel supercomputational machines. The eventual MODELS-3 system will\nincorporate computer systems in excess of 1000 parallel processors. Appropriate scientific visualization\ntechniques are being developed.\nA preliminary assessment of the atmospheric deposition of toxic pollutants to the Lake Michigan watershed\nwas completed using the Regional Lagrangian Model of Air Pollution (RELMAP). Upper and lower bounds\nof deposition were estimated for 40 distinct toxic pollutants by using a wide range of deposition velocities\nin the model. Two sets of Regional Oxidant Model simulations were performed in support of the Lake\nMichigan Ozone Study. In one set, the meteorological inputs were derived from routine National Weather\nService meteorological measurements; in the other, the meteorological inputs were obtained from a prognostic\nmeteorological model. The results were used to initialize a newly developed urban-scale photochemical\nmodel (UAM V).\nThe Regional Oxidant Model was also used to examine whether local control of NO emissions in the\nNortheast could be avoided by applying more stringent VOC emission controls in adjacent states, and by\nadopting the California Low Emissions Vehicle Program in the transport region. It was found that while\ncontrol of VOC emissions is of benefit, strong local control of NO emissions will still be needed. The results\nwere reported in June 1992 and are being used to help formulate regional control policies for attainment of\nthe ozone National Ambient Air Quality Standards in the Northeast.\nFluid Modeling\nWork on a Plume Rise/Downwash Project has commenced, to develop an algorithm for estimating\nbuilding-downwash effects when effluent is emitted from a short stack in the vicinity of a building. The\noverall project will involve field measurements and theoretical developments by other groups, and laboratory\nmeasurements to be conducted in Japan. The ASMD contribution thus far involved 3 months of wind-tunnel\nmeasurements on plume dispersion in the vicinity of both steam-boiler and combustion-turbine electrical\ngenerating stations. These generic studies include a typical plant of each type, with systematic variations of\nthe five most significant nondimensional parameters: stack height, distance between plant and stack, wind\ndirection, effluent speed, and effluent buoyancy.\nA wind-tunnel simulation of dispersion from area sources was conducted, to help modify area-source\ndispersion algorithms for use at Superfund sites. A study of the concentrations of pollutants from point\nsources near rectangular buildings was also completed. Areas for each building were identified where stack\nplacement would violate \"Good Engineering Practice.\" Another study addressed the removal of dense gas\nfrom a topographical depression in a crosswind. The density and flow rate of the gas input at the bottom of\na V-shaped valley in otherwise homogeneous terrain were together sufficiently small to prevent pooling of\nthe gas in the valley bottom (i.e., to prevent decoupling of the valley fluid from the winds aloft), but were\nnevertheless sufficiently large to significantly reduce the flushing times from that of a neutral gas. A simple\ntheory was developed to describe how heavy gas is removed by turbulent entrainment from the separated\n128","Air Resources Laboratory\nflow in the valley. The results provide a framework for estimating how long a heavy-gas spill will take to\ndisperse from depressions with steep sides.\nClimate Diagnostics\nThe EPA Environmental Monitoring and Assessment Program (EMAP) statistical summaries were used\nin studies of hurricane frequencies, high winds, ice storms, precipitation, and late spring freeze events.\nTropospheric ozone and rural surface ozone were also addressed as part of the global change program.\nPatterns in tropospheric ozone estimated from satellites were identified.\nModel output from a Pacific Basin ocean model was compared to satellite-derived sea surface temperature.\nBoth visualization and analytic techniques were used to examine the period of record, 1982-1989, which\nincluded both El Niño and La Niña events.\nPlans FY 93\nAnalysis of the STAGMAP study will be completed, including analyses of vertical and horizontal\nturbulence during extremely low wind speed conditions. The data will be used to develop a new model to\naccount for decoupled multiple layers of stable drainage.\nThe mobile pollutant flux measuring system will be deployed at various NDDN sites as a full-scale test\nof the system. Additional capabilities for determining deposition of HNO3 will be developed to augment the\ncurrent capability to measure ozone, SO2, and the meteorological fluxes including heat, moisture, and\nmomentum.\nAnalyses and modeling studies will be performed for the Southern Oxidant Study (SOS) field measurement\ncampaign to be conducted in the Atlanta región during the summer of 1993. Concurrently, preliminary\nplanning for the next major field study to be held in the Nashville area will begin.\nA demonstration project will develop a practical method for generating hourly meteorological fields of\nwinds, temperature and moisture, mixing layer heights, and surface layer stability parameters on an 80-km\ngrid for the entire United States for 1 full year.\nMany existing models will be refined, to permit application in special contexts: the use of RELMAP to\nassess airborne toxic deposition into the Great Lakes watershed, and the estimation of nitrogen deposition to\nthe Chesapeake Bay using the RADM system. The RADM will be improved by including recent formulations\nof cloud processes, incorporating asymmetrical convective mixing for daytime conditions, and adding more\ngeneralized nesting features. The RPM will be modified by including a visibility module. We will begin to\ndevelop the initial version of the MODELS-3 system.\nThe Regional Oxidant Model, the RADM, and the Aeronomy Laboratory Model will be compared. Initial\nsteps will be taken to derive explicit treatments of elevated point source plumes within a Eulerian grid model\nframework, and to develop methods for addressing heavier than air gaseous emissions and for upgrading the\nIndustrial Source Complex (ISC) modeling techniques for characterizing emissions from area sources and\nparticulate deposition.\nFlow and dispersion in complex terrain and around obstacles will be studied by the Fluid Modeling Facility,\nwith emphasis on basic boundary-layer characteristics and dense-gas plumes.\nEMAP statistical summaries will be used to provide climate information for the biennial assessment\nrequired by the Clean Air Act Amendments of 1990. Satellite data will be used in a pilot project for EMAP\nagroecosystems research called the Normalized Difference Vegetation Index (NDVI). An objective clima-\ntological classification scheme for homogeneous regions will be developed using a clustering technique that\n129","classifies each day according to synoptic-scale meteorological patterns. Development of an ozone climatol-\nogy will be initiated for the United States and for the globe using satellite estimates of tropospheric ozone.\nFIELD RESEARCH DIVISION\nAccomplishments FY 92\nField Studies\nIn December 1991 and January 1992, a carbon monoxide (CO) tracer study was conducted in the Utah\nValley under the sponsorship of the Utah Air Resources Board. Two industrial CO sources were tagged with\ninert chemical tracers: one with BCF (bromochlorodifluoromethane) and the other with SF6 (sulfur\nhexafluoride). A new application was developed to monitor CO in a source stack and to provide feedback to\ncontrol the amount of SF6 released. A network of surface meteorological towers and tracer samplers was set\nup, supported by a radar wind profiler and Radio Acoustic Sounding System (RASS). Results of CO, tracer,\nand meteorological analyses indicate that the major source of CO in the valley is vehicle emissions. The flow\nwas controlled by nearby mountains, Utah Lake, the urban heat island, and valley temperature inversions.\nIn January-February and again in July-August, the Field Research Division was a major player in the\n1992 Measurement of Haze and Visual Effects (MOHAVE) Field Intensives. The research, sponsored by\nEPA and Southern California Edison, was aimed at characterizing the sources, air flow, and dispersion of\nhaze-producing agents flowing into the Grand Canyon, Bryce, and Zion National Parks. Gas tracer release\nequipment was developed and operated at four sites in Utah, Nevada, and California; sampling equipment\ncritical to the campaigns was maintained at an array of ground stations.\nA new balloon-borne Global Positioning System (GPS) was developed for the International Global\nAtmospheric Chemistry Marine Aerosol and Gas Exchange (IGAC-MAGE) experiment. During the study,\nchemical tracers were released to help determine air flow important to the sulfur budget in the marine\nboundary layer. The work was performed on the Woods Hole Oceanographic Institution ship Oceanus while\nit was stationed in the Azores. The equipment was operated successfully for more than 1 month, and the\nprototype GPS proved to be a very useful tool for increasing the quality of data from constant level balloons.\nA new automated gas chromatograph and computer analysis system was developed for analyzing CO. The\nsystem was first used to analyze CO from the Utah Valley study. Unique features are the ability to detect CO\nin quantities of less than 20 parts per billion in a sample of 5 mL or less. This enables accurate quantification\nof CO in tracer samples, an ability not generally available to the scientific community. The system is\ncomputer-driven and is considerably faster than earlier analyzers.\nAircraft Vortices\nThe FAA's Vortex Wake Program seeks to minimize the effects of aircraft trailing-vortex hazards and to\nincrease airport capacity by specifying safe separation distances for aircraft. To support this objective, the\nFAA asked FRD to investigate vortex wake characteristics of the newer-generation, relatively heavy, twin\nengine jet transports. A flight test program in 1990 collected vortex wake data as a function of specific\natmospheric indices and aircraft configurations. In FY 92, all data analyses were completed. A significant\nfinding was that some twin engine aircraft produce wake vortex hazards comparable to those from heavy\nthree and four engine transports. The study also observed the largest tangential vortex velocity ever found.\n130","Air Resources Laboratory\nRecommendations from this and other findings could have significant impact on safe aircraft separations,\nand therefore the operational capacities at many U.S. airports.\nEmergency Response and Preparedness\nNew HP 9000/730 UNIX computers and the first newly instrumented meteorological towers were installed\nat the Idaho Falls site and began to supply data. A draft quality assurance plan was completed and submitted\nto DOE to guide operation of the meteorological portion of the Idaho National Engineering Laboratory (INEL)\nresponse system. Emergency models were coded for transfer to the new computer system. FRD scientists\nparticipated in two emergency response exercises, and a third emergency situation that was later determined\nto be a false alarm. In all cases, the MESODIF and other transport and diffusion models were successfully\noperated with data and forecasts communicated to INEL response centers.\nFRD scientists served as consultants to the State of Idaho Dose Assessment and Risk Advisory Panel, the\nINEL Waste Management Site Selection Committee, and NOAA's Hazardous Materials Response and\nAssessment Division.\nScientists, engineers, and technicians of FRD designed and conducted a 6-week training course for four\nEgyptian engineers. Sponsored by the NRC Office of Scientific and Engineering Personnel's International\nAtomic Energy Fellowship Program, the course covered general and air pollution meteorology, laboratory\nmethods including the theory and practice of gas chromatography, and chemical tracer technology. Several\nfield experiments provided hands-on experience in preparing, releasing, sampling, and analyzing tracers.\nPlans FY 93\nThe final reports of field research in the Utah Valley, MOHAVE, and IGAC-MAGE studies will be\ncompleted. Data taken from the Princeton Plasma Physics Laboratory (PPPL) study of 1988 will be\nreanalyzed, a real-time dose equivalent monitoring system will be designed for the PPPL, and an Internet\nlink with the PPPL will be established. FRD will participate in the design and conduct of an interagency\naerosol experiment at the Kennedy Space Center.\nAdditional enhancements will be designed for the newly developed gas chromatograph system. FRD will\ndevelop six prototype GPS systems for NOAA's Hazardous Materials Response and Assessment Division in\nSeattle. The systems will allow NOAA's on-site responders to quickly catalogue the location and type of\nhazard nearly anywhere in the world.\nA 2-year project will be started to rescue decaying meteorological and air chemistry data from field studies\nduring the past 20 or more years. The data will be made available to the larger research community and to\nFRD scientists for response and prediction model development and testing.\nMeteorological forecasting, climatological, and modeling capabilities will be added to the upgraded\ncomputer system to enhance emergency support. A major demonstration of basic capabilities will be made\nto DOE and NOAA management in December. As part of the support to INEL, the waste management site\nselection process will be provided with meteorological analyses and expertise based on the upgraded\ndata base.\n131","AEROSOL RESEARCH SECTION\nAccomplishments FY 92\nA cooperative project under way since September 1991 with the South Korean Ministry of the Environment\ninvolves a pollution monitoring site on the windward side of Cheju Island. ARS instrumentation to measure\nozone, nitrogen oxides, and sulfur dioxide will continue operating on the island through December 1992.\nThe Asian continent is fast becoming the largest source for nitrogen oxides and sulfur oxides in the world.\nCheju Island is strategically located east of China, south of the Korean peninsula, and east of Japan. Thus,\nemissions from all three sources can be monitored from this site.\nBetween September and December 1991, emissions of ozone and nitrogen oxides were monitored on the\ncoast of China as a part of the western Pacific Exploratory Mission (PEM-West). This program seeks to\nunderstand the fate of anthropogenic pollutants as they leave China and are advected eastward. This series\nof measurements enhances the parallel measurements made by the Cheju Island station.\nThe ARS participated in the Atlantic Stratocumulus Transition Experiment (ASTEX) during June and July\n1992. Measurements were made aboard the Mt. Mitchell between Miami, Florida, and the Azores (west of\nPortugal). Prime interest was in characterizing the distribution of marine aerosols.\nA series of research flights was conducted near Boulder to compare the ozone concentrations measured\nby four different ozone sensors. These flights were arranged after laboratory experiments revealed that some\nozone sensors have a sensitivity to atmospheric humidity as well as to ozone. The flight tests confirmed that\nthis was the case. This sensitivity is significant given the rapidly changing humidity conditions encountered\nby research aircraft.\nThe ARS participated in the Front Range Lidar-Aircraft-Balloon (FRLAB-3) program during August and\nSeptember 1992, This program measures the atmospheric aerosol profile with three different techniques and\ncompares them. FRLAB-1 and FRLAB-2 demonstrated the feasibility of this approach and confirmed that\nthe\nthree different measurement systems yield comparable results. FRLAB-3 was the final and confirmatory\ndeployment in this series of field experiments.\nA first step was taken in developing a flux measurement system for the NOAA King Air research aircraft.\nDuring FY 92, an inertial navigation system was tested. This system allows the precise computation of aircraft\nattitude, position, speed, and acceleration as a function of time. This information is required for accurate\nmomentum flux calculations.\nPlans FY 93\nA desert dust experiment will be conducted to measure dust emission, transport, and deposition factors\nabove the arid Owens Lake, in California, in cooperation with a group of Russian scientists. This experiment\nis scheduled for March and April 1993. It will combine surface-based, aircraft-based, and satellite-based\nmeasurements of blowing dust with a sophisticated numerical modeling study. In addition, the results from\nthis study will be used to \"ground-truth\" the satellite information SO that it can be extrapolated to other\ngeographies. A cloud physics study is being planned for near the coast of California, to contrast the\nmicrophysical characteristics of polluted and adjacent unpolluted clouds. It will serve as a first link in\nexplaining the recent finding of trends in global cloudiness. Together with the U.S. Bureau of Reclamation\nand the State of California, a study will be conducted to determine the effectiveness of propane as a cloud\nseeding agent above the mountains of northern California. The program is scheduled for the period between\n132","Air Resources Laboratory\n15 January and 15 March 1993. The NOAA King Air research aircraft will be used to measure the\nmicrophysical characteristics of the clouds subject to propane seeding.\nIn collaboration with the U.S. Forest Service, work will commence to establish and maintain an aerosol\nand visibility monitoring network at Forest Service sites throughout the United States. This network will\nmeasure the aerosol loading, its bulk nature, and the visibility at each sampling site. This new network is\nmandated by the 1990 Clean Air Act.\nA further step in the development of a chemical flux measurement system for the NOAA King Air will be\nthe implementation of a system for measuring the fluctuating component of the wind. This will be an\nadaptation of the ATDD technique. Fabrication and testing of this system should be completed during\nFY 93.\nDevelopment of remote sensing techniques to detect and study large-scale dust storms will continue, in\ncooperation with the USGS. ARS is cooperating with the National Geophysical Data Center Paleoclimate\nproject in examining visibility records and National Park Service aerosol monitoring data. The intent is to\ndefine relationships between dust and other climatic variables that can be used for paleoclimate research.\n133","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nAERONOMY LABORATORY\nBoulder, Colorado\n(303) 497-5785\nDaniel L. Albritton, Director\nThe Aeronomy Laboratory (AL) conducts research on chemical and physical processes of the Earth's\natmosphere to advance the capability to monitor, predict, and protect the quality of the atmosphere. The\nresearch concentrates on the stratosphere and troposphere, but also involves the mesosphere and\nthermosphere.\nThe research methods involve in situ and remote measurement of critical atmospheric parameters,\nincluding chemical composition and dynamic properties such as wind velocity, turbulence, and wave motion.\nTheoretical programs in atmospheric photochemical modeling and in atmospheric dynamics and transport\nsupport the observation programs. An experimental laboratory chemical kinetics program supports the\ntheoretical photochemical modeling program and also supplies input for the development of new atmospheric\nmonitoring and measurement technology.\nThe major focuses of research are air quality and climate. Several environmental issues are currently\naddressed: stratospheric ozone depletion (global, Antarctic, and Arctic), tropospheric ozone production by\npollutants (both in rural continental areas and globally), greenhouse effect, acid rain, El Niño-Southern\nOscillation (ENSO), and climate change. The Laboratory plays a major role in providing scientific advice\nin these areas to policymakers.\nATMOSPHERIC WAVES AND TURBULENCE THEORY\nThis program is devoted to theoretical studies of turbulence, wave, and eddy transport of constituents,\nenergy, and momentum in the atmosphere. These phenomena are basic to many areas of geophysics, including\nmeteorology, climatology, pollution dispersal, oceanography, and space physics.\nWave and turbulence fluctuations have a striking effect on transport of pollutants and were intensively\nobserved as long as three decades ago. However, because of mathematical and conceptual difficulties, no\n135","theories of turbulence and nonlinear wave interactions were available for determining the strength of the\nfluctuations and how they influence pollution dispersal and meteorology. The development of such theories\nhas become a principal concern of this program.\nAccomplishments FY 92\nTurbulence Modeling\nDerived equations that predict the energy spectrum caused by wind shear. These spectra are required\nfor reliable predictions of the planetary boundary layer.\nDeveloped a theory to predict viscous dissipation of atmospheric fluctuations, a major sink of\natmospheric fluctuations.\nInitiated a theory to determine turbulence cascade (breakdown of larger turbulence eddies into\nsmaller ones).\nAtmospheric Gravity Waves\nCompleted a theory to predict the spectrum of unsaturated gravity waves. These waves determine\ngravity wave sources as well as atmospheric wind variability.\nDetermined the species diffusivity caused by gravity waves in the middle atmosphere.\nInitiated a theory to determine the spectrum of temperature fluctuations in the atmosphere.\nPlans FY 93\nTurbulence Modeling\nInitiate theory to predict all directional components of velocity-velocity correlations in sheared flows.\nComplete the theory of turbulence cascade.\nAtmospheric Gravity Waves\nComplete the theory of temperature fluctuations caused by random phased gravity waves in the\nmiddle atmosphere.\nContinue development of a nonlinear theory of monochromatic gravity waves in the atmosphere.\nSuch waves are a source of the observed intermittency of turbulence in the troposphere, stratosphere,\nand mesosphere.\n136","Aeronomy Laboratory\nATMOSPHERIC CHEMICAL KINETICS\nThis program investigates chemical and photochemical reactions that take place in the Earth's atmosphere.\nThese processes are studied in the laboratory under chemically isolated conditions to obtain data for individual\nreactions. Environmental problems such as photochemical air pollution, acid precipitation, global warming,\nand stratospheric ozone depletion are addressed. Most atmospheric reactions involve free radicals, which\nare highly reactive molecular fragments. Radical reactions are studied directly, using a variety of production\nand detection methods to investigate isolated chemical processes. Reaction rate coefficients, optical absorp-\ntion coefficients, quantum yields, and reaction mechanisms are examples of the products of this program.\nThese data are used to understand the effects of natural and anthropogenic chemicals on the environment.\nAccomplishments FY 92\nThe reaction of CIONO with HCI on ice surfaces was shown to proceed via two steps: the formation of\nHOCI in the reaction of CIONO2 with H2O, followed by the reaction of HOCI with HCI. This mechanism\nmakes it easier to understand and model this reaction in atmospheric systems.\nThe reactions of OH with CH3Br and CH2B12 were measured. The rate coefficient for the CH3Br reaction\nwas found to be ~50% slower than in previous studies. The rate coefficient for the CH2Br2 reaction was\nmeasured for the first time. These measurements help define the atmospheric lifetimes and the ozone\ndepletion potentials (ODPs) of these compounds.\nThe reactions of Cl atoms with many HCFCs and HFCs were measured. It was shown that the loss of\nHCFCs and HFCs via their reactions with Cl atoms in the atmosphere is unlikely to be important.\nVarious processes that can destroy fully fluorinated species were studied. It was shown that photolysis in\nthe vacuum ultraviolet (UV) region at 121.6 nm is the primary pathway for the destruction of most of these\ncompounds. It was deduced that these molecules persist in the atmosphere for centuries and hence can be\nvery potent greenhouse gases.\nThe absorption spectrum of Cl2O3 and the equilibrium constants for the reaction CIO + OCIO = Cl2O3\nwere measured. Based on this information it was deduced that Cl2O3 is unlikely to be a major reservoir for\nstratospheric chlorine and that its formation would not enhance ozone loss.\nThe rate coefficient for the reaction of OH radical with CH3CCl3 was measured to be approximately 20%\nslower than in previous results. This measurement places the calculated global average tropospheric OH\nconcentrations on a firmer basis and reduces the lifetimes and ODPs of many HFCs, HCFCs, and methane.\nThe heterogeneous reaction between HOCI and HCI was shown to be very efficient. The discovery of this\nnew reaction helps explain some of the features of the Antarctic ozone loss.\nMethylvinyl ketone and methacrolein are two key intermediates in the atmospheric oxidation of isoprene,\nthe most abundant naturally occurring nonmethane hydrocarbon (NMHC). Their reactions with the OH\nradical and UV absorption cross sections have been studied. These data define the atmospheric lifetimes of\nthese compounds.\nA chemical ionization mass spectrometer was used to detect several radicals involved in the oxidation\nmechanisms of the CFC substitutes. The rates and mechanisms of the atmospheric oxidation of the CF3\nradical were elucidated. A new molecule, CF3OH, that is formed in the atmosphere was discovered. These\nresults provide a quantitative basis for modeling the degradation of CFC substitutes.\n137","Plans FY 93\nMeasure the UV absorption spectra of atmospherically important molecules such as HNO3 and\nCIONO as a function of temperature.\nInvestigate activation of gas-phase reservoir bromine species by reactions on ice and in sulfuric acid.\nInvestigate the mechanisms in the oxidation of dimethyl sulfide, especially the conversion of the\nintermediate CH3S radical to SO2.\nInvestigate the reactions of Cl atoms with bromocarbons.\nInvestigate the reactions of OH radicals with atmospherically important alkanes and halogenated\nspecies.\nDesign and construct a chemical ionization mass spectrometer for detection of trace gases at pressures\nup to 0,1 atmosphere.\nContinue studies on the atmospheric lifetimes and of the oxidation processes of CFC substitutes.\nATMOSPHERIC DYNAMICS\nThe Atmospheric Dynamics Program combines observational and theoretical studies of atmospheric\ndynamical processes, focusing on internal gravity waves and vertical air motion. Our immediate objective\nis to improve understanding of these dynamical processes, but the results of our research contribute to\nimprovements in weather forecasting and the transfer of advanced meteorological measurement technology\nto operational uses.\nMuch of our research uses data taken at the Flatland Meteorological Observatory (FMO), located in very\nflat terrain near Champaign-Urbana, Illinois. The principal instrument at FMO is a 50 MHz wind-profiler\nor stratosphere-troposphere radar. Such radars measure the wind nearly continuously, compared with the\ntwice-daily routine balloon soundings, and they can also directly measure vertical velocity.\nAccomplishments FY 92\nIn October 1991, a vertically pointing 915 MHz radar was installed at FMO to measure vertical wind\nvelocities in the first 1-2 km of the troposphere, which cannot be observed by the 50 MHz radar. At the same\ntime, a meteorological ground station was installed to measure the surface wind, temperature, pressure,\nprecipitation, and solar insolation. In January 1992, 17 sensitive air pressure sensors (barographs) were\ninstalled across Illinois at stations of the Illinois Climate Network to augment the array of 6 barographs that\nhad been installed around FMO in FY 91. These sensors are used to detect the passage of fronts and to\nmeasure the wavelength and velocity of gravity waves.\nOn 21 December 1991, the sensors of FMO observed large, long-lived periodic perturbations of the\npressure, solar insolation, surface wind, and vertical wind through the troposphere due to a train of gravity\nwaves generated by shear on the bottom of the overhead jet stream. Analysis of such an extraordinarily large\nand well-observed event will be very useful for understanding the generation of gravity waves by jet streams.\nIn July 1992, a Radio Acoustic Sounding System (RASS) was installed on the 915 MHz radar to measure\ntemperature profiles in the lower troposphere. The resulting vertical wind and temperature profiles are being\nused to study the heat flux in the atmospheric boundary layer.\n138","Aeronomy Laboratory\nThe FMO participated in the national Stormscale Operational and Research Meteorology Fronts Experi-\nment System Test (STORM-FEST) program from 1 February to 15 March 1992.\nDuring the last decade, a model for the mean field of propagating gravity waves was developed, in large\npart by AL research. During FY 92, we used this model to develop a theory for the resulting acceleration of\nthe winds as a function of altitude. Inclusion of this theory into general circulation models should result in\nimprovements in weather predictions.\nWe have shown that the horizontal wind velocities inferred from the 50 MHz radar are in excellent\nagreement with winds from National Weather Service radiosonde balloon analyses that have been interpolated\nto the location of FMO.\nOn the other hand, the 50 MHz radar vertical velocities in the middle troposphere are observed to have an\naverage downward bias of about 5 cm This bias and the more general question of the accuracy of the very\nimportant vertical velocity measurements are the subject of intensive research.\nPlans FY 93\nUpgrade the 915 MHz radar to a five-beam configuration to measure the horizontal as well as vertical\ncomponents of the wind.\nInstall an interferometric radar at the Flatland site, to be operated by Georgia Institute of Technology\nand Clemson University for several months to compare the capabilities of two different kinds of\nradars and to study the radar echoing process. Then the interferometric radar will be moved to a\nstation about 25 km to the east, to form a triangle with the Flatland and Urbana wind-profiling\nradars to measure atmospheric divergence and vorticity, which are important parameters for\nweather forecasting.\nContinue development of the spectral model of gravity waves, including studies of their sources, and\nfurther improve our model for atmospheric acceleration due to a spectrum of gravity waves.\nTROPICAL DYNAMICS AND CLIMATE\nThe research goal of the Tropical Dynamics and Climate Program is to improve understanding of tropical\ncirculation and its impact on global climate. The primary contribution of the research lies in the use of\nremote sensing wind profilers developed within AL to provide continuous information on atmospheric\nwinds in the tropical Pacific. A close link is maintained with programs such as Tropical Ocean Global\nAtmosphere (TOGA).\nAccomplishments FY 92\nRoutine wind observations at Christmas Island were made for TOGA. These observations are used\noperationally by the world meteorological centers, and monthly summaries of the winds are published in two\nclimate bulletins.\nComparison of winds observed at Christmas Island during the past year with observations made over the\npreceding 5 years shows the clear influence of El Niño. Lower tropospheric winds observed at Christmas\nIsland are substantially weaker than normal. Occasional episodes of lower tropospheric westerlies have been\nseen since late 1991. Upper tropospheric winds have been much weaker than normal. The zonal winds\n139","observed at Christmas Island depend on the strength of the Walker Circulation, which weakens substantially\nduring El Niño.\nLower tropospheric winds have been observed at Christmas Island since March 1990 using a 915 MHz\nboundary layer radar. The boundary layer radar measures wind nearly continuously from about 100-m\naltitude to 3 to 5 km, depending on atmospheric conditions. Preliminary analyses have focused on the vertical\nstructure of the trade wind regime at Christmas Island. Owing to Christmas Island's location in the central\nequatorial Pacific just north of the Equator, several features stand out in the lower tropospheric wind field.\nMost of the time the intertropical convergence zone (ITCZ) lies to the north of Christmas Island and\nthe\nequatorial cold tongue of sea-surface temperature (SST) lies to the south of the island. Consequently,\nlow-level meridional flow is almost always from south to north and backs\" with height, consistent with cold\nair advection. Preliminary comparisons of these observations with analyses from the European Centre for\nMedium-Range Weather Forecasting (ECMWF) reveal systematic problems in the analyses.\nAnalyses of diurnal and semidiurnal oscillations in winds observed at Christmas Island are being pursued\nin collaboration with the University of Colorado. Results to date indicate that the profiler observations agree\nwith atmospheric tidal models, indicating that the profiler is observing the large-scale migrating tide.\nDuring the past year, the Trans-Pacific Profiler Network (TPPN) was completed. The last VHF wind\nprofiler in the network commenced operation at Biak, Indonesia, in March 1992. The network now comprises\nVHF Doppler wind profilers at Piura, Peru; Christmas Island, Kirabati; Pohnpei, Federated States of\nMicronesia; and Biak, Indonesia.\nThe UHF wind profiler was successfully integrated with an Omega Sounding System and surface\nmeteorological sensors to create the first Integrated Sounding System (ISS). This project is being pursued\njointly with the Atmospheric Technology Division of the National Center for Atmospheric Research (NCAR)\nto support the atmospheric sounding system needs for TOGA and the TOGA Coupled Ocean Atmosphere\nResponse Experiment (COARE). The first ISS was installed at Manus Island, Papua New Guinea. Additional\nISSs are being deployed at Kavieng, Papua New Guinea; Kapingamarangi, Federated States of Micronesia;\nand Nauru; and on three research vessels. These ISSs constitute the Intensive Flux Array (IFA) for\nTOGA COARE.\nPlans FY 93\nContinue operations at Christmas Island with TOGA funding, transmit 6-hourly data via satellite to\nthe scientific community, and archive, at AL, high-resolution optical disks.\nOperate the TPPN to obtain observations in support of our tropical and climate research programs.\nParticipate in the field phase of TOGA COARE to help maintain the integrity of the IFA. Begin a\ndetailed analysis of intraseasonal variability of the atmospheric circulation within the COARE\nlarge-scale domain as part of the COARE research effort.\nBegin deployment of several UHF lower tropospheric wind profilers to tropical Pacific locations in\nsupport of enhanced monitoring for TOGA. Candidate sites are Tarawa and the Galapagos.\nMove the ISS that will be located at Kavieng during TOGA COARE to Nauru after the field phase\nof TOGA COARE is complete. In addition, we plan to continue to develop the capability of\nunattended operation of profilers on uninhabited islands.\nContinue collaborative research with the University of Colorado and the Australian Bureau of\nMeteorology Research Centre, utilizing the observations of the TPPN.\nBegin using the capability of the boundary layer radar to observe precipitating cloud systems and\nexplore ways to classify complex precipitation systems in terms of deep convective \"hot towers,\"\n140","Aeronomy Laboratory\nstratiform convection, and low-level convection. As a pilot project, we will classify precipitation\nobserved at Christmas Island.\nContinue to use the available tropical Pacific rawinsonde data base as well as Pacific wind profiler\nobservations in studies of coupling mechanisms between the ocean and the atmosphere. The role of\nconvection and radiation processes in the coupling will be explored, and fluctuations of convection,\nSST, and humidity on interannual and decadal time scales will be examined. The behavior and\nvertical structure of ENSO warming at extratropical latitudes will be investigated.\nTHEORETICAL AERONOMY\nThe Theoretical Aeronomy Program undertakes theoretical studies of important atmospheric problems,\nconstructs and uses computer models of the chemistry and dynamics of the troposphere, and analyzes data\ncollected within the Laboratory and by collaborative experiments. In recent years, the principal research\nactivities have focused on issues of global change and regional air pollution such as radiatively important\ntrace gases, tropospheric oxidants, and acid precipitation. The ultimate goal of the program is to attain a\nsufficient understanding of the composition and energy budgets of the atmosphere SO that trends can be\naccurately predicted.\nAccomplishments FY 92\nIn collaboration with two international field experiments, the East Asian-North Pacific Regional Experi-\nment (APARE) and the North Atlantic Regional Experiment (NARE), studies with the AL three-dimensional,\nmesoscale transport-photochemical model were started. Major objectives of both experiments are to examine\nthe transport of tropospheric ozone and ozone precursors from populated and industrialized continental areas\nto the adjacent oceans. During both experiments, high concentrations of ozone and other pollutants indicate\nthe importance of anthropogenic emissions for the distribution of these trace gases.\nThe first phase of a comprehensive tropospheric chemistry experiment over the western Pacific, PEM-\nWest, which is a subproject of APARE, was completed in October 1991. This international and interagency\nexperiment has made extensive, high-quality measurements of greenhouse gases (CO2, CH4, N2O, and O3),\naerosols, and other gases important to atmospheric chemistry over a vast area in the western Pacific. Our\ngroup contributed to the experiment by serving as a co-mission scientist, by conducting modeling studies,\nand by measuring water vapor. The preliminary results were reported at the Second American Geophysical\nUnion Western Pacific Meeting held in Hong Kong, 16-21 August 1992. The data collected during this study\nwill be valuable input for assessing the global warming potential (GWP) of trace gases and aerosols.\nObservations of the vertical distribution of ozone made during the APARE and NARE experiments, along\nwith the results from other field studies, emphasize that it is critical to correctly describe the exchange of\nozone and primary pollutants from the planetary boundary layer to the free troposphere. In the free\ntroposphere, the lifetime of radiatively important trace gases such as ozone is longer and horizontal transport\nis more efficient than within the boundary layer.\nClouds play an important role in the vertical redistribution of trace gases in the atmosphere with differences\nfor soluble and insoluble trace gases. Cloud transport and chemistry have been incorporated into the\nthree-dimensional model description. The measurements made during the APARE and NARE experiments,\ntogether with those from the Rural Oxidants in the Southern Environment (ROSE II) study completed in July\n1992, provide the data needed to improve the theoretical description of these processes in the regional models.\n141","Plans FY 93\nInvestigate the effects of aerosols on solar radiation and in turn on regional scale climate through\nmodeling and collaborating field experiments by this Laboratory and the Climate Monitoring and\nDiagnostics Laboratory (CMDL). Preliminary results indicate aerosols may have a significant\nimpact on the diurnal temperature range and on some important regional-scale meteorological\nphenomena.\nCarry out comprehensive analysis of the PEM-West and NARE data over the next 2 years. The foci\nwill be tropospheric O3 budget and distribution, and the biogeochemical cycles of greenhouse gases\nand aerosols. Results of the analysis of the PEM-West data will be a critical input for designing the\nsecond phase of the experiment, which will be conducted in the spring of 1994.\nStudy the contribution of natural and anthropogenic emissions to the formation of ozone in the rural\ntroposphere, the exchange of boundary layer air with the free troposphere, and the processes\ncontrolling the flux of ozone and the reactive odd nitrogen species in the planetary boundary layer\nusing measurements obtained during the ROSE II campaign.\nOPTICALAERONOMY\nThe Optical Aeronomy Program uses spectral measurements to study fundamental atmospheric processes\nin the troposphere and stratosphere. The center for the observational program is the Fritz Peak Observatory\nlocated in the mountains west of Boulder, Colorado, at an elevation of 8500 ft.\nAccomplishments FY 92\nTropospheric OH Radical\nMajor progress was made in the development of the long-path tropospheric OH experiment at Fritz Peak.\nLong-path absorption of UV laser light is now being used on a regular basis to measure spectroscopically the\nOH concentration between Fritz Peak and Caribou Mine 11 km away. This critical tropospheric molecule\nhad eluded reliable measurement until this experiment came on line. The detailed intercomparison campaign\nwith the Georgia Institute of Technology was successfully completed, and the results were presented at the\nAmerican Geophysical Union meeting in December 1991. An entire session was planned around the\nmeasurements, and both experimental and theoretical results were presented. A landmark paper was\npublished in a core journal describing this first successful intercomparison campaign, the low concentrations\nmeasured, and the small change between early morning and peak noontime values.\nTropospheric Trace Species Long-Path Experiment\nRecognizing that the chemistry of OH cannot be understood from a single-species measurement, a new\nlong-path experiment is now measuring ozone, water vapor, nitrogen dioxide, formaldehyde, sulfur dioxide,\nand other molecules over the same long path in the troposphere at the same time OH is measured. A new\ndouble spectrograph with a reticon array detector is used. This experiment is producing very high quality\ndata that are critical in interpreting the changes observed in OH concentration.\n142","Aeronomy Laboratory\nStratospheric OH Radical\nThe ground-based absorption measurements of stratospheric OH continued at Fritz Peak Observatory.\nPreviously reported OH abundances persist in the stratosphere. New theoretical analyses indicate an effect\nof lower stratospheric OH on total column OH through the presence of a previously unknown layer of odd\nhydrogen in the lower stratosphere. An interferometer similar to the one at Fritz Peak was deployed to Lauder,\nNew Zealand, and is producing new, high-quality Southern Hemisphere data that show a significant decrease\nin average OH levels during austral spring.\nInternational Network for Detection of Stratospheric Change\nA program started in 1989 to develop a new observing system to measure stratospheric trace gases using\nspectroscopic absorption of light in the UV and visible portions of the spectrum is nearing fruition. The\ninstruments developed as part of this program will be installed at several global locations. The prototype\ninstrument has been installed at Fritz Peak Observatory and has produced a year of ozone and nitrogen dioxide\n(NO) data. The eruption of the Mount Pinatubo volcano makes this data set very important since large\nchanges in NO2 noted in the Southern Hemisphere immediately after the eruption were not measured at Fritz\nPeak even after the arrival of the volcanic cloud. The first production model of the system was completed\nin April 1991 and participated successfully in the international NO2 intercomparison campaign at Lauder,\nNew Zealand, in May 1992. Data from the instrument were analyzed and submitted to the blind referee.\nWork on a new analysis system is nearing completion and a computerized data base is under development.\nPlans FY 93\nContinue routine measurements of tropospheric OH. Full seasonal determinations of ozone, water\nvapor, nitrogen dioxide, formaldehyde, SO2, and other molecules in support of the OH experiment\nare under way.\nConduct a large intercomparison campaign in summer 1993 for hydroxyl measurements. Partici-\npants will include Pennsylvania State University, Georgia Institute of Technology, Washington State\nUniversity, and AL.\nUse the OH Pesios interferometers at Fritz Peak and Lauder, New Zealand, to produce another full\nyear of data for the two hemispheres.\nComplete development and prototype testing of the new trace gas measurement system. The first\nproduction instrument will begin observations at the NOAA Mauna Loa Observatory in Hawaii and\nan instrument will be deployed to McMurdo Station, Antarctica as part of the joint NOAA-National\nAeronautics and Space Administration (NASA) program for early detection of stratospheric change.\nDetermine temperature-dependent NO2 cross sections as part of a community effort to standardize\nthese cross sections.\nBegin development of a new IR Fourier transform instrument for determining tropospheric OH sink\nspecies, particularly hydrocarbons.\n143","METEOROLOGICAL CHEMISTRY\nThe major focus of the Meteorological Chemistry Program is the interaction between chemical composi-\ntion and meteorology in the upper troposphere and lower stratosphere, a region that is important to global\nchange, both scientifically and for policy-making. The program's effort is focused on two specific research\nareas: (1) the meteorological and chemical state of the lower stratosphere, from pole to pole over the whole\nannual cycle; and (2) the content of water vapor and ice in the global upper troposphere, and how it is affected\nby cross-tropopause transport.\nAccomplishments FY 92\nInstrument Development\nThe new airborne instrument for simultaneous NO and NO measurements operated successfully during\nthe second Airborne Arctic Stratospheric Expedition (AASE-II), including the fast-response gas chroma-\ntograph for CFC 11 and 113 built by CMDL. The NO and NO instrument is being considered for expansion\nto include a channel for NO2, which will greatly enhance knowledge of the nitrogen oxide and chlorine\nphotochemistry in the lower stratosphere. The laboratory version of the aerosol laser ionization mass\nspectrometer has successfully taken spectra of aerosol particles, and efforts have begun to produce a\nfield\ninstrument for ground use, followed by design of an airborne instrument. Laboratory experiments with far\ninfrared laser magnetic resonance techniques have led to a preliminary design for an airborne/balloon\ninstrument for measuring the ground state oxygen atom, which is the reactant common to all four rate-\ndetermining steps in the catalytic cycles responsible for ozone loss outside the polar vortices. Studies are\nunder way for the design and construction of lightweight instruments to measure methane and water vapor.\nAirborne Missions\nThe AASE-II mission involved five test flights of the ER-2 high altitude aircraft from Moffett Field,\nCalifornia, during August and September 1991, followed by a total of 25 scientific flights from Fairbanks,\nAlaska, during October and from Bangor, Maine, from December to March. The program's instruments\nperformed very well, and there promises to be invaluable new information on the chemical balance in the\nlower stratosphere, which was heavily loaded with aerosol from Mount Pinatubo.\nData Analysis and Publication\nSeveral papers devoted to polar ozone appeared in the core, refereed literature. The analysis of past\nmissions continues hand in hand with that of the large dataset from AASE-II. Time was also spent in\nacquiring ECMWF data for the Antarctic winter of 1987 and the Arctic winter of 1989, and an in-house\ncapacity was generated to produce such diagnostics as potential vorticity fields and three-dimensional\nair parcel trajectories.\n144","Aeronomy Laboratory\nPlans FY 93\nInstrument Development\nContinue work on the design of an airborne version of the laser ionization aerosol mass spectrometer\nvia a field version designed for near-surface observations.\nSeek funds to design and construct an airborne balloon version of a far infrared laser magnetic\nresonance instrument for the measurement of ground-state oxygen atoms, O(3P).\nConsider the potential of chemical ionization mass spectrometry for airborne measurements.\nAirborne Missions\nParticipate in an ER-2 field mission during October and November 1992, the Stratospheric Photo-\nchemistry, Aerosol, and Dynamics Expedition (SPADE), which is being run as part of NASA's High\nSpeed Research Program, aimed at understanding the effects of exhaust emissions from possible\nfuture fleets of supersonic transport aircraft.\nData Analysis and Publication\nReport on the scientific output from the Stratosphere-Troposphere Exchange Project (STEP) tropical\nmission and the AASE-II mission.\nPublish results from the Halogen Occultation Experiment (HALOE), and continue data analysis\nassociated with this instrument.\nTROPOSPHERIC CHEMISTRY\nAccomplishments FY 92\nGlobal Ozone Production\nNorth Atlantic Regional Experiments\nMeasurements of ozone production and transport from the North American continent over the Atlantic\nOcean were undertaken in response to the growing concern that long-range ozone transport may influence\nair quality on an interhemispheric scale. Ozone and CO were measured at sites on the Atlantic coast of\nCanada, allowing study of the changing composition of air masses containing pollutants from eastern North\nAmerica as these air masses were carried into the North Atlantic. These results indicate that, during the\nsummer over the temperate North Atlantic, the quantity of ozone generated photochemically from anthropo-\ngenic emissions on the North American continent exceeds that injected from the stratosphere.\n145","Mauna Loa Observatory Photochemistry Experiment\nA second mission to Mauna Loa was concluded. The study, called the Mauna Loa Observatory Photo-\nchemistry Experiment (MLOPEX), consisted of four 6-week campaigns conducted in the fall of 1991 and\nthe winter, spring, and summer of 1992 at the CMDL Mauna Loa Observatory in Hilo, Hawaii. The aim of\nthe mission was to investigate the processes that shape the seasonal distribution of ozone and the photochemi-\ncal precursors of ozone in the remote free troposphere. Three important constituents of the budget of ozone\nprecursors were measured: nitric acid (HNO3), nitrate particulate (NO3-), and total reactive nitrogen (NO).\nThese data, which are being analyzed, will give a seasonal representation of the photochemical processes\nthat control ozone production in the remote free troposphere.\nRegional Ozone Production\nMeasurements of volatile organic compounds\nUntil recently, the measurement of volatile organic compounds (VOCs) was restricted to fully reduced\ncompounds, i.e., hydrocarbons. However, the improvement of measuring techniques by AL now permits the\nmeasurement of partially oxidized compounds such as aldehydes, ketones, and alcohols. Recent studies\ncarried out at Niwot Ridge, a rural location in the Colorado mountains, indicate that approximately 70% of\nthe hydrocarbons measured during the day are partially oxidized VOCs. Approximately one-half of this\ngroup were alcohols, principally methanol and methyl butanol. The compounds appear to be direct emissions\nfrom the forests, and their emission at this location appears to be of the same order as that of isoprene, the\nprincipal hydrocarbon emitted from the forest.\nThese observations, if representative of forest emissions elsewhere, have important atmospheric conse-\nquences. First, methanol has been suggested as a potential alternative motor fuel. The large natural\nbackground of methanol that may be associated with emissions from forests will reduce the potential impact\nof possible future anthropogenic emissions of this compound. Second, the longer lifetime of methanol will\nallow that compound to be disseminated into the global atmosphere. Finally, the expected large reactivity of\nmethyl butanol will allow it to play a significant role in the formation of regional oxidants.\nRural Oxidants in a Southern Environment\nHigh levels of ozone are observed over large regions of the United States during the summer. These\nelevated ozone concentrations are detrimental to human health and cause crop and vegetation damage. During\nthe summer of 1992, ROSE II studied the formation of ozone in the southeastern United States. Our research\nfocused on determining the chemical processes whereby the ozone is formed. This study was designed to\naddress three key questions: (1) What processes are responsible for exchange between the planetary boundary\nlayer and the free troposphere? (2) Can current models adequately simulate these processes? (3) Are air\nconcentrations of ozone precursors at a surface site representative of emissions of those compounds within\nthe surrounding region?\nThis research program combined (1) a comprehensive suite of chemical measurements at the ROSE ground\nstation, (2) airborne measurements of key compounds using fast-response instruments, and (3) height profiles\nof the dynamical properties of the free troposphere. The measurements were obtained under a variety of\nmeteorological conditions and provide a robust data base. The data are being analyzed.\n146","Aeronomy Laboratory\nBiosphere-Atmosphere Exchange\nMeasurements of NO emission from forest soils in the United States have been made using the enclosure\ntechnique. The measurements made at Kinterbish, Alabama, and Niwot Ridge indicate that emission of NO\nfrom forest soils is small and not a significant source of atmospheric NO. This agrees with earlier\nmeasurements made by our group at forest locations elsewhere. In addition, a study of NO and NO flux via\neddy correlation was done at the Kinterbish site. Results from this study are being evaluated and will be\ncompared with the chamber data taken at the site.\nDevelopment of Measurement Capability\nThe study of atmospheric photochemistry requires unequivocal measurements of NMHCs. Great headway\nhas been made in ground-based measurements of these compounds. However, the distribution of the\ncompounds as a function of altitude is very uncertain. To this end, an airborne system for the measurement\nof NMHCs was constructed and successfully tested at the surface.\nNitric acid plays a critical role in the transport of reactive nitrogen and in the balance of the reactive nitrogen\nbudget in the atmosphere. There are lingering concerns regarding potential systematic errors that may be\ninvolved in the filter measurements of HNO3. As an alternative method for this measurement, a continuous-\nflow denuder system using on-line ion chromatographic detection was built. The measurements made with\nthis new method were compared with those made using the older filter technology during the ROSE II study.\nThese results are being analyzed.\nPlans FY 93\nRegional Ozone Production\nOzone is the byproduct of the oxidation of hydrocarbons and CO in the presence of NOx. Unfortunately,\nthe hydroxyl radical, which is presumed to be responsible for this oxidation, is difficult to measure in the\natmosphere. However, with the emergence of new techniques these measurements are now becoming\npossible. During the summer of 1993 we will\nCollaborate in experiments designed to help evaluate emerging new techniques to measure OH: a\nlong-path optical technique developed in AL, and two in situ OH-measurement techniques being\ndeveloped by colleagues elsewhere.\nProvide in situ measurements of NO, NO2, NO, NMHCs, and O3 at the location of the in situ\nmeasurement of OH.\nInterpret the results of this fundamental study of the oxidizing properties of the atmosphere and the\ntechniques to measure them with the help of the Theoretical Aeronomy group.\nGlobal Ozone Production\nParticipate in a new, 1993 summer intensive of NARE, with the goal of better determining the budget\nof ozone in the North Atlantic troposphere utilizing both ground-based and airborne measurements.\n147","Study the distribution of anthropogenic and cotransported secondary pollutants to better understand\nthe oxidizing capacity of the North Atlantic troposphere and the reactive nitrogen balance\nObtain vertical profiles of ozone and meteorological parameters to determine if the surface meas-\nurements give an accurate picture of the transported species. These measurements will be supported\nby vertical wind profiles measured at Cape Cod and Newfoundland and additional surface ozone\nmeasurements at Cape Cod.\nMIDDLE ATMOSPHERE STUDIES\nThe objective of the Middle Atmosphere Studies Program is to undertake theoretical and field studies\naimed at a fuller understanding of the chemistry and transport processes taking place in the Earth's middle\natmosphere (approximately 10 to 100 km). The field program is based primarily on acquisition and\ninterpretation of optical data from sites such as McMurdo Station, Antarctica, and Fritz Peak, Colorado.\nParticular emphasis is placed on further understanding the processes that control stratospheric ozone depletion\nand predicting its future.\nAccomplishments FY 92\nField Measurements\nSince the discovery of the Antarctic ozone hole, many studies have been aimed at understanding the\ncomposition of the Antarctic stratosphere during the springtime period of maximum ozone depletion.\nHowever, it is also clear that Antarctic ozone is decreasing in fall and winter compared to historical\nmeasurements, raising the question of whether ozone depletion processes that are chemically driven can take\nplace during these other seasons. Further, the possibility of transport of chemically perturbed air from the\nAntarctic to lower latitudes (e.g., New Zealand) could potentially contribute to the substantial ozone depletion\nnow observed at midlatitudes of the Southern Hemisphere during much of the year. These questions can only\nbe addressed through detailed measurements of the chemical composition of the stratosphere, not only to\nelucidate the depletion of ozone but also to identify its causes. To address these issues, the same ground-based\nvisible spectroscopy instruments that were used to measure some of the first chemical perturbations in\nAntarctica were deployed at McMurdo Station throughout an annual cycle. The measurements revealed\nabundances of chlorine dioxide in midwinter that are at least 100 times greater than gas-phase model\npredictions, showing the first observational evidence for wintertime Antarctic chemical perturbations.\nFurther, concurrent observations of nitrogen dioxide and nitrogen trioxide gave insight into the amount of\nsunlight that the air had been exposed to. The two sets of measurements taken together suggest that significant\nozone depletion can occur during Antarctic winter (not just in spring). The wintertime ozone losses can be\nexpected to increase as chlorine and bromine concentrations mount during the next decade.\nStratospheric and Mesospheric Modeling\nUnder current international agreements, stratospheric chlorine will continue to increase over the next\ndecade, reaching the highest levels ever experienced on this planet. Further, hydrochlorofluorocarbons and\nother compounds will be increasingly used as environmentally preferable substitutes for the chlorofluorocar-\nbons. The relative effects of the variety of anthropogenic compounds that are expected to contribute to ozone\n148","Aeronomy Laboratory\nloss during the next several decades are therefore a subject of considerable interest to scientists and\npolicymakers alike. A new, semi-empirical method to evaluate the ODPs of various compounds over the next\nseveral decades has been developed. The method has placed the basis for calculating these key policy-\nrelevant indices on firmer footing than previous studies, and has shown that the short-term ODPs of some\ncompounds are likely to be considerably larger than their long-term values, providing the scientific framework\nneeded to make choices regarding future emissions.\nPlans FY 93\nAnalyze and interpret measurements of nitrogen dioxide and ozone in the Antarctic during February\nthrough November 1992, and compare them to 1991 measurements. This period is of particular interest\nbecause of the large amount of volcanic particles present in the Antarctic stratosphere due to the\neruption of Mount Pinatubo, allowing study of possible chemical perturbations due to these particles.\nDevelop a coupled wave/mean flow model for studying stratospheric chemistry.\n149","","Office of the\nDirector\nJoint\nInstitutes\nAOML\nGLERL\nFSL\nWPL\nARL\nSEL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nSPACE ENVIRONMENT LABORATORY\nBoulder, Colorado\n(303) 497-3311\nErnest Hildner, Director\nThe Space Environment Laboratory (SEL) provides uninterrupted space environment services to its\ncivilian and military customers. SEL also conducts research on the solar-terrestrial environment and develops\ntechniques for applying new research understanding to services.\nTo accomplish these activities most effectively, SEL was reorganized in FY 92. The former three-division\nstructure was streamlined into two divisions, the Services Division and the Research and Development\nDivision.\nThe relocation of the U.S. Air Force (USAF) space environment services center from Omaha, Nebraska,\nto Colorado Springs, Colorado, has encouraged closer ties between that service center and SEL. Visits and\ndiscussions of mutual problems are frequent.\nIn FY 93 SEL plans to adjust its research efforts. Research into solar wind-magnetospheric coupling will\nbe given greater emphasis, and studies of interplanetary scintillation (IPS) will subside; however, cooperation\nwith U.S., Mexican, Russian, Indian, and Japanese IPS colleagues will continue. Further adjustments will\nbe made to emphasize solar image processing (e.g., providing automatic recognition and location of solar\nfeatures, thereby enabling automatic warning when a feature disappears or changes rapidly).\nSERVICES DIVISION\nFY 92 was notable for a decline in sunspot numbers, an increase in the number of geomagnetic storms,\nthe use of x-ray images of the Sun from the Japanese satellite Yohkoh, and the opening of the USAF Space\nForecast Center (SFC) at Falcon Air Force Base, near Colorado Springs. The Space Environment Services\nCenter (SESC) is located within SEL. It is operated jointly by the USAF, through its SFC Command, and\nSEL; SESC duties are shared by civilian and military forecasters. SESC's basic forecasts, summaries of solar\nand geophysical activity, and alerts of disturbances are distributed to other federal agencies, the general public,\nand other countries. The new SFC supports Department of Defense (DOD) programs, redistributes SESC\n151","products to DOD, and provides its unclassified, specialized products for redistribution through SESC to users\nworldwide.\nTypically, a peak in geomagnetic activity occurs 2-4 years after sunspot maximum, but the frequency of\nstorms in the current cycle (sunspot maximum occurred in 1989) has already exceeded that of recorded past\ncycles. The Yohkoh images are proving useful in analyzing possible sources of geomagnetic storms. These\npictures give dramatic three-dimensional images of solar activity, clearly showing mass ejections and great\nexpansions of the solar atmosphere. If these ejections reach Earth, destructive geomagnetic storms are\nproduced, causing serious disruption of satellite operations, power systems, and navigation. The Yohkoh\nimages also give unprecedented views of the formation and disappearance of solar coronal holes, from which\nsolar atmosphere can flow out rapidly and buffet Earth with another type of geomagnetic storm.\nThe daily images from Yohkoh are a precursor of the continuous x-ray images expected from future\nGeostationary Operational Environmental Satellites (GOES). In addition to the x-ray images, SESC expects\nto give 1-h alerts from a future satellite at the L1 libration point, balanced between Sun and Earth. Together,\nthese exciting new resources will enable SESC to provide better service than ever before.\nAccomplishments FY 92\nSpace Environment Operations\nTo improve SEL's understanding and prediction of space weather, additional sources of solar and\ngeophysical data were investigated. Solar x-ray images were received from the Japanese Yohkoh spacecraft,\nthe only source of these data, and additional geomagnetic field observations were obtained via the Intermagnet\nProgram. Arrangements were made with NASA and USAF for SESC to receive critical information from\nthe planned NASA WIND/SWIM (Solar Wind Interplanetary Measurements) spacecraft, which will monitor\nthe solar wind.\nSolar monitoring telescopes of the USAF Solar Electronic Observatory Network (SEON) supply the\nmajority of solar optical and radio data used by SESC. These instruments were upgraded, allowing access\nby SESC to new data sets including digital solar images.\nForecasting\nSpace environment forecasts have historically been plagued with uncertainty, mostly due to the lack of\nkey data and understanding of the behavior of space weather that leads to disturbances. A new era in\ngeomagnetic forecasting began on 1 September 1992, when SESC issued the world's first geomagnetic\nprobability forecast. Forecasters can now communicate the degree of confidence in their forecasts, and users\ncan plan their operations on the basis of better information.\nNew tools to evaluate space weather forecasts continue to come on line. Approximately one-half of the\nplanned forecast-verification package is now complete. Detailed specifications were developed for\na\ncontinuous series of these products, tailored to meet the needs of data users, managers, and forecasters.\nSESC staff, in cooperation with the USAF, developed a method for making long-term predictions of\nsmoothed sunspot numbers and the 10.7-cm radio flux. Now recognized as the nation's official 10-year\nprediction of the solar cycle, this forecast gives users a more reliable, objective, and consistent product that\nwill assist them in making critical decisions for future operations. This work completes a long-standing\nagreement between SEL and USAF.\nA new code for the daily, international GEOALERT forecast was implemented in SESC, facilitating\nSESC's function as the World Warning Agency (WWA). The code improves the description of the\n152","Space Environment Laboratory\nsolar-terrestrial environment, standardizes the advice made to WWA by the Regional Warning Centers in\nother countries, and provides coded summaries of disturbances. Implementation of this code followed its\napproval by the Steering Committee of the International Ursigram and World Days Service (IUWDS), who\nacted on behalf of the International Council of Scientific Unions.\nData collection and archiving\nTo further reduce operating costs, improve access to unique data sets, and speed up the exchange of data,\nmore data collection and product delivery processes were switched to electronic networks. Most of the data\nexchange with IUWDS Regional Warning Centers is now accomplished via these networks, which have\nreplaced the slower and more expensive teletype systems.\nA new program for transferring and viewing images, which allows access to SEON and Yohkoh, was\ndeveloped using the new File Image Transfer System (FITS) format.\nA data transfer and display server system was completed and is in use at the Poker Flat Rocket Range\n(PFRR) and the Geophysical Institute in Anchorage, Alaska. This system allows scientists at PFRR to display\nand analyze the data in the SEL Data Acquisition and Display System (SELDADS) as they make rocket-\nlaunch decisions.\nCustomer services\nA customer focus group was formed to gather and consolidate information on users of SESC products and\nto evaluate user needs. Current information on users was reviewed for inclusion in a customer data base.\nPreliminary statistics on users and their needs were prepared, and results were published.\nBesides the usual customer support, SESC handled more than 1000 requests for special services, including\nsupport for four international solar observing campaigns and five rocket launches for the Max '91 program\n(described under the Solar Physics subsection of this report). In addition, SESC participated in more than\n20 outreach activities, assisted in the search for a downed television helicopter, gave interviews and\nbackground information to the media, and provided a wide variety of educational material.\nSESC provided extensive technical support to the USAF as the new SFC was put into operation. Major\nsoftware development was provided, a new magnetometer analysis program was created to produce global\ngeomagnetic indices, and miscellaneous guidance was given to USAF staff.\nSpecial Projects\nIPS observations\nThe IPS antenna at Cambridge, England, continued to function on an automatic, quasi-operational basis.\nThe IPS site in India was revisited, an engineering review was performed, and a data acquisition system was\ninstalled. Discussions were held with the Florida Institute of Technology regarding the installation of a third\nIPS site in Florida, the Caribbean, or Mexico. Multiple sites are required if IPS is ever to yield reliable\nforewarning of interplanetary disturbances. (The Interplanetary Physics subsection of this report describes\nIPS research within SEL.)\n153","GOES Space Environment Monitor and Solar X-ray Imager\nSEL continues to assist the National Aeronautics and Space Administration (NASA) Goddard Space Flight\nCenter in monitoring the contractors for the Space Environment Monitor (SEM) instruments scheduled to\nfly on the GOES I-M series of spacecraft. The spacecraft program continues to be delayed by problems with\nmeteorological instruments. Problems with magnetometers have been corrected. The Energetic Particle\nSensor (EPS) and High Energy Proton and Alpha Detector (HEPAD) systems and the magnetometers have\nall been delivered to the spacecraft contractor for integration. An SEM is now installed on GOES-I and is\nundergoing integration testing.\nFollowing advice by SEL, NOAA decided to fabricate the Solar X-ray Imager (SXI) instrument at NASA's\nMarshall Space Flight Center. The instrument requirements were simplified to keep the program within\nbudget, and fabrication began in April 1992. Considerable progress has been made in refining the design\nproposed during the preliminary study completed in FY 91. A formal review of requirements, a preliminary\ndesign review, and delivery of the instrument to the spacecraft contractor have been scheduled.\nEarth System Data and Information Management data rescue and access\nSEL successfully proposed for Earth System Data and Information Management (ESDIM) funding to\nrescue the SEM data from the Television and Infrared Observation Satellites (TIROS) and from GOES. These\ndata have been residing on half-inch magnetic tapes, some of which are 15 years old and all of which are in\na format that will be difficult to read when the CYBER computer is retired next fiscal year. Equipment has\nbeen purchased, contractor staff has been hired, and programs have been developed for transfer and\nrevalidation of the TIROS data. The National Geophysical Data Center (NGDC) is developing a parallel\nprogram for rescuing the GOES data, which will also be accessible to SEL.\nComputer networking\nIn collaboration with the National Institute for Standards and Technology and the Institute for Telecom-\nmunication Sciences, the local area network (LAN) was expanded. It now consists of an Ethernet backbone\nwith bridged extensions for each of the major groups in the building. Access to the National Science\nFoundation's Internet as well as NASA's Space Physics Analysis Network (SPAN) and Internet was improved\nby the installation of a new NASA router, connected by a link to the scientific network backbones at the\nNational Center for Atmospheric Research (NCAR).\nSEL is involved in the planning of computer networks and telecommunications within the planned NOAA\nbuilding on the Broadway site; a NOAA-wide network structure is also under study.\nScientific data base system\nStudies began to define the objectives of a general-purpose, on-line data base to provide SEL staff with\nimmediate and convenient access to historical data on the space environment.\n154","Space Environment Laboratory\nPlans FY 93\nSpace Environment Operations\nMonitoring\nDevelop operational requirements for solar wind information to be captured from a satellite at the\nL1 libration point.\nWork with the SFC to integrate improved observations from the solar optical and radio telescopes at\nthe SEON facilities.\nForecasting\nContinue to provide 24-hour-a-day space weather services.\nDevelop improved geomagnetic activity guidance for forecasters.\nBegin regular production of reports verifying the accuracy and other attributes of SESC forecasts.\nConduct one-on-one forecaster training sessions (using outside experts) on using the results of the\nverification reports.\nDevelop procedures for verifying the new geomagnetic probability forecasts.\nDevelop and prioritize, with the SFC, a list of technique development topics.\nData collection and archiving\nFind new ways to provide reliable Space Environment Monitor (SEM) data from the GOES-6 and\nGOES-7 satellites as they increasingly degrade, filling data gaps with data from GOES-5.\nContinue to provide 24-hour-a-day operation of the SELDADS2, which has been experiencing failure\nof aging equipment as well as environmental problems, while awaiting implementation of\nSELDADS3.\nContinue to upgrade SEL's data systems to match the upgrades in data transfer and communication\nsystems; replace communication interfaces with DOD, move more user services to electronic\nnetworks, connect a new data-transfer system from the U.S. Geological Survey, and prepare to receive\nquasi-real-time data from the WIND/SWIM satellite.\nConvert the Boulder Observatory to a digital system; eliminate the old chemical-based darkroom\nand file processing.\nDevelop and implement the transfer of solar images in new formats from the SEON system to SEL.\nAssist the Image Processing Project in developing and testing algorithms for space environment\nservices; some of the routines will be developed within SEL, and others will use the advanced\nKB-Vision software.\nConvert the SEL Solar Image System (SELSIS) to allow the transfer of solar magnetograms from\nthe Kitt Peak Observatory in terms of directly measured magnetic field strengths (replacing the\ndegraded images now used in SESC operations).\nExpand, complete, and document a data transfer and display system (XSEL), designed for the PFRR,\nand make it available to other consumers of SEL's real-time data; begin using XSEL to explore and\ndevelop forecast functions in a multiwindowed environment on standard computer platforms.\n155","Reduce the level of technical support to the Table Mountain, High Latitude Monitoring Station\n(HLMS), and Thule field sites.\nContinue to replace old data system preprocessors with new personal-computer-class systems as\nexternal interfaces and data sensors evolve. This task includes the development of new software for\nthe next generation of GOES satellites.\nCustomer services\nImprove SEL's information on users and their needs, and develop a marketing plan based on\nthose needs.\nConduct a survey to ask users how they obtain SEL products and services; compile their responses.\nAnalyze current services and products, using perspective gained from user surveys.\nDesign newsletters and other educational material for users.\nWork with the SFC to provide increased mutual backup capability.\nProvide support to research programs, including two scheduled Max '91 observing campaigns.\nContinue to advise the user community regarding adverse effects of disturbances in the solar-\nterrestrial environment, giving special attention to effects on navigation and electric power systems.\nSpecial Projects\nContinue the joint operation of the Cambridge IPS system, and evaluate its operation; encourage the\nIndian program as appropriate; participate in planning for a Western Hemisphere site.\nContinue to assist NASA in monitoring the SEM and SXI implementation by their contractors.\nComplete rescue of the TIROS data and begin providing on-line access within SEL to both the TIROS\nand GOES data sets.\nComplete the Broadway site telecommunications network; complete plans for integrating all Depart-\nment of Commerce Boulder networks in preparation for the relocation of laboratories in the new\nbuilding.\nBegin implementing the scientific data base prototype, using the new network file server system as\na host.\nRESEARCH AND DEVELOPMENT DIVISION\nThe former Research Division is now the Research and Development Division, and contains three\nbranches: Space Influences on the Terrestrial Environment (SITE), Geospace, and Solar/Interplanetary.\n156","Space Environment Laboratory\nSPACE INFLUENCES\nON THE TERRESTRIAL ENVIRONMENT BRANCH\nThe SITE Branch is composed of all elements of the former Atmosphere-Ionosphere-Magnetosphere\nProject and all efforts concerning the Solar Influences theme within NOAA's Climate and Global Change\nProgram. The latter efforts include the solar observations obtained by the Solar Backscatter Ultraviolet\n(SBUV) instruments on NOAA satellites and SEL's initial work on coupling processes in the upper\natmosphere and magnetosphere. Therefore, this branch has assumed responsibility for all aspects of SEL's\nresearch involving magnetospheric-ionospheric-atmospheric coupling, centered on data obtained from the\nTIROS satellites, and all Laboratory research into solar influences on climate and global change.\nAccomplishments FY 92\nSolar Influences\nThe SITE Branch's work within the Solar Influences theme of the NOAA Climate and Global Change\nProgram began in earnest in FY 92. A strategic planning document was prepared to provide the framework\nfor NOAA-wide and extramural involvement in this program. SEL is initially focusing on quantifying the\nenergy input to the atmosphere of particles and photons from the Sun and the magnetosphere, using\ninstruments on the GOES and TIROS satellites. (In the second phase of the program, SEL will evaluate the\natmospheric consequences of that input.) A related study of the importance of auroral production and\ntransport of nitric oxide (NO) was completed.\nSolar Ultraviolet Radiation Research\nThe Proceedings of the Workshop on the Solar Electromagnetic Radiation Study for Solar Cycle 22\n(SOLERS22) was printed. These proceedings present the current knowledge of temporal variations in total\nsolar irradiance as well as solar ultraviolet (UV), extreme ultraviolet (EUV), x-ray spectral irradiance, and\ntechniques for modeling these variations from ground-based measures of solar activity.\nThe core-to-wing ratio (RMgII) for the Solar Mg II h and k lines was derived, through June 1992, from\nmeasurements made by the SBUV-2 monitors aboard the NOAA-9 and -11 satellites. Algorithms for use\nin estimating RMgll back to 1947, before SBUV measurements were made, have been largely derived. Models\nof temporal variations of solar UV radiation and EUV fluxes in the chromosphere have been developed, based\non RMgII as a measure of solar activity. Alternative measures of coronal flux are being evaluated.\nMesosphere-Thermosphere-Ionosphere Studies\nDespite extensive research, ionospheric storms are poorly understood phenomena. Understanding of the\nbasic physical processes has not enabled prediction of the ionosphere's response to storm inputs. Researchers\nare using numerical simulations to learn more about the thermosphere's response function in the hope of\ndeveloping a comprehensive empirical description of ionospheric storms.\nIt is also important to understand the climatology of the ionosphere. Current models tend to underestimate\nthe middle-latitude F-region ionospheric density when solar activity is high. This inadequate specification\ncauses disagreement between models and observations. A working version of a global thermosphere-\nionosphere-plasmasphere model was assembled and is being tested with colleagues at England's Sheffield\n157","University. A study of the effect of ion convection channels on the thermosphere and the ionosphere produced\nthe following findings: the ionospheric response is dominated by chemical effects caused by a massive\nincrease in ion temperature, and changes in neutral thermospheric composition have a smaller influence.\nAnother aspect of thermospheric response revealed is the generation of large-scale gravity waves that\npropagate globally.\nOperational Satellite Instruments\nSEL monitored operation of the SEM on the NOAA-12 satellite and directed the National Environmental,\nSatellite, Data, and Information Service (NESDIS) Space Operations Control Center (SOCC) in its recovery\nfrom anomalies in the Total Electron Detector (TED). The contract for the SEM-2, scheduled to fly on the\nNOAA-K, -L, and -M spacecraft in the mid-1990s, continued under SEL supervision. The engineering\nmodel was fabricated, and environmental tests began. The ground support equipment (GSE) was fabricated,\nand software was written and tested. The GSE was successfully demonstrated. Numerous test procedures\nwere written, and fabrication of flight hardware continued. SEL assisted the spacecraft contractor in preparing\nfor integration and test of the SEM-2 on NOAA-K.\nPlans FY 93\nConvert TIROS archival processing software from the CYBER to SEL's computer system.\nTransfer TIROS energetic-particle and solar UV data into an SEL data base.\nEvaluate the response of NO to a solar flare.\nCompare in detail the modeled NO response to auroral activity with observations, and interpret the\nanomalous latitude structure of NO.\nDocument the analysis and derivation of the RMgII from NOAA-9.\nDocument the model of solar chromospheric EUV fluxes.\nDevelop procedures for filling in the missing RMgII data.\nResolve the coronal-index controversy and develop a model of the temporal variations of solar\ncoronal EUV fluxes.\nExamine the response function of the thermosphere to geomagnetic storms.\nEvaluate the coupled model of the global thermosphere, ionosphere, and plasmasphere.\nBegin development of a mesospheric chemistry model.\nQuantify the variability of input of the more energetic particles to the atmosphere.\nContinue supervision of the SEM-2 contract for TIROS. Accept delivery of the engineering model,\nthe protoflight model, and the first flight model of the TIROS SEM-2.\nPlan the procurement of future SEM instruments for NOAA and European satellites.\n158","Space Environment Laboratory\nGEOSPACE BRANCH\nThe former elements of Magnetospheric Physics, as well as new personnel and programs, constitute the\nnew Geospace Branch. This branch is responsible for processing data and conducting research using\nobservations, gathered from sensors aboard satellites and at ground stations, that measure the state of the\nmagnetosphere. These observations, and related theoretical models, are used to improve our understanding\nof the magnetosphere, primarily from the magnetopause to the ionosphere. This branch has identified four\nspecific arenas of endeavor: understanding the basic physical processes at work in the magnetosphere, to\nimprove space environment services; understanding the charged-particle environment of Earth, including\ngalactic and solar sources and trapped, energized, and precipitating particle populations; understanding the\nnominal and disturbed geomagnetic field, on the ground and extending to the magnetopause (including the\nmagnetotail); and serving as a resource for SESC, offering long-term guidance and training as well as\nshort-term advice to the duty forecaster.\nAccomplishments FY 92\nFour papers that developed models to investigate equilibria, stability, and the dynamics of the magneto-\nspheric tail were published. Predictions of physical behavior under specified conditions were confirmed\nusing observations from the AMPTE (Active Magnetospheric Particle Tracer Explorer) satellite.\nThe complete data set from the GOES-6 HEPAD, from launch in 1983 through July 1992, was processed\nand analyzed. The resulting data base is now archived on magneto-optical disk. Acatalog of 54 geostationary\nmagnetopause crossings (GMCs), occurring between 1983 and 1992, was assembled using the GOES\nmagnetometer data archive. GMCs are major geomagnetic disturbances that occur when enhanced solar\nwind compresses the magnetosphere SO severely that geostationary satellites, at 6.6 Earth radii, are moved\noutside the magnetopause. Finally, the computer animation of the TIROS/NOAA energetic particle data maps\nwas redesigned and software implementation was completed. This display shows 3-day running-average\nmaps of any two channels of energetic particle data.\nSEL signed a Memorandum of Agreement (MOA) with NASA to send NOAA GOES data to the Global\nGeosciences Central Data Handling Facility across existing computer networks. The GOES \"key parameter\"\ndata are added to those from several other NASA spacecraft, and all data are available to SEL.\nRoutine surveillance of the GOES data stream recognized and diagnosed abnormal behavior of spacecraft\nor telemetry systems or problems with computer processing hardware or software. These problems have\nbeen increasing as the GOES fleet has aged.\nPlans FY 93\nConvert GOES archival processing software from the CYBER to the SEL computer system.\nCreate GOES SEM data bases.\nProvide GOES magnetometer \"key parameter\" data to NASA as specified in the MOA.\nAcquire and interpret real-time solar wind data from the WIND/SWIM satellite starting in the late\nsummer of 1993.\nInitiate empirical and theoretical studies to model and predict the geomagnetic response to variations\nin the solar wind.\nObtain and evaluate the Rice University Magnetospheric Specification Model.\n159","Study magnetospheric equilibria and catastrophic processes in the magnetotail current sheet; extend\nmodels to two dimensions and investigate substorm triggers and the effects of cross-tail magnetic\nfields.\nProduce a CD-ROM containing 5 years of NOAA-10 energetic particle environment data and\nsoftware for computer animation and visualization.\nUse HEPAD data to estimate radiation doses at aircraft altitudes.\nSOLAR AND INTERPLANETARY BRANCH\nAll Research Division projects involving solar and interplanetary research, except those investigating solar\ninfluences on climate and global change, have been combined into this new branch.\nAccomplishments FY 92\nSolar Physics\nH-alpha synoptic charts were produced for a study of high flare activity in 1991. Coronal holes were\nmapped from Hel 10830 spectroheliograms for August 1991-July 1992. Disk maps derived from these partial\ncharts were made to overlay on the new x-ray images.\nStatistical and morphological studies of regions producing type-III radio bursts were made in collaboration\nwith the Observatoire de Paris.\nEach of the parameters used in the McIntosh system to classify solar active regions was assessed for its\nstatistical contribution to flare occurrence; the system was then analyzed and several possible changes that\ncould result in improved forecasts were identified. Work is under way to address whether the decay of active\nregions and their possible residual effects can be used to explain long-term variations of solar fluxes. Studies\nof solar image processing and feature recognition yielded algorithms for recognizing solar filaments and\nlarge-scale magnetic field patterns on the Sun. A commercial software package was used to develop\ncomputer-understandable definitions of solar features, and correction algorithms were developed to address\nthe noncircular appearance of some solar images.\nA study of high-temperature flares suggested that there are two categories of solar flares hotter\nthan\n25\nMK: those that are intrinsically hot and those that appear to be hot because they are near the solar limb. The\nhot flares near the limb suggest a strong vertical thermal stratification of flare plasmas and a larger-than-\nexpected absorption or scattering of x-rays in the lower atmosphere.\nA study of simultaneous x-ray measurements from two satellites, the Russian PROGNOZ and NOAA's\nGOES, demonstrated that the evolution of a two-component flare plasma can be discerned by dual\nobservations. The flare plasma thermalizes at the approximate time of x-ray maximum and remains\nisothermal throughout the flare's decay process.\nA study of solar energetic particles (SEPs) and x-ray flares has shown that SEPs associate with anomalously\nlow-temperature flares at low-to-moderate flare intensities and with gradual hard x-ray flares at high levels\nof flare intensity. These complementary relationships may prove useful in forecasting SEP events for all\nflares larger than M1.\nThe principal diagnostic parameters derivable from broadband soft x-ray measurements are coronal\nplasma temperature and emission measure. A method was described to compute these parameters,\nincluding assessment of instrument errors and environmental influences. A statistical test of accuracy,\n160","Space Environment Laboratory\nbasedon temperature comparisons with the spectroscopic findings from two experimental satellites, was\nalso presented.\nSEL's support of the Max '91 program of coordinated international solar observations continued. Three\nmajor observing campaigns were executed, with direction from SEL. A digital archiving system for the USAF\nSolar Observing Optical Network (SOON) observatories was developed, and tape recorders were installed\nat all sites. A process to distribute real-time soft x-ray data from GOES to the Yohkoh team is under\ndevelopment.\nInterplanetary Physics\nAn empirical algorithm to predict the total flux and anisotropies of particles up to about 2 MeV in\nadvance of an interplanetary shock's arrival at Earth was completed in collaboration with Spanish\ncolleagues. A three-dimensional interplanetary global model (3D IGM) was used to simulate interplanetary\nmagnetic \"bottles\" and associated bidirectional streaming of low-energy electrons and protons behind\ninterplanetary shocks.\nParametric studies of the time of arrival of shocks at Earth continued, using the 2D IGM; a predictive\nmodel was developed. This model's predictions were compared with observed data; the increased complexity\nof the numerical model does not add appreciable accuracy.\nEvaluation of all-sky maps of IPS, provided by the Mullard Radio Astronomy Observatory at Cambridge,\nEngland, indicates that these maps, by themselves, are not useful for operational forecasting of geomagnetic\nactivity. The meridian-scan antenna takes too long to map the entire visible sky, and the maps are often\ncompromised by the presence of ionospheric scintillation, which can mask IPS events. To improve mapping\nperformance, at least one more observatory would be required.\nThe 3D IGM was used to produce simulated IPS whole-sky \"g-maps\" of various hypothetical solar wind\ndisturbances. A 2-month IPS observing campaign was conducted in collaboration with English and Indian\ncolleagues. In one case, an SEL shock-propagation forecast prepared after the occurrence of solar flares was\nfaxed to India with recommendations for observations; the Indian velocity-map and g-map data confirmed\nthe existence of traveling interplanetary disturbances. This is the first time that a remote-sensing technique\nhas been used to image such a disturbance in response to a specific propagation forecast from SEL. Formal\ncontractual arrangements with SEL's collaborators at the Physical Research Laboratories in India expired\nin March 1992. Progress there has been disappointingly slow; only 24-25 radio sources are currently\nbeing monitored.\nCollaboration continued with the University of Alabama in Huntsville on the coupling of coronal\ndisturbances into the interplanetary medium.\nThe two-volume proceedings of last year's symposium of the Solar Connection to Transient Interplanetary\nProcesses (SOLTIP) project, led by SEL staff, was distributed. SOLTIP has encouraged colleagues in Russia\nand China to complete their IPS observatories and then contribute their data to SEL.\nCollaboration continued with colleagues at Tel-Aviv University to obtain a magnetohydrodynamic (MHD)\nsolution for the steady-state solar wind flow around coronal helmet streamers; this work has developed\nmathematically from the 2D to the 3D level. Despite progress, closure of the MHD solution for thermally\nconducting plasmas has not yet been achieved for the 2D case.\n161","Plans FY 93\nSolar Physics\nResume the regular publication of solar maps.\nComplete the H-alpha synoptic charts of large-scale patterns of \"neutral\" lines and Hel 10830 coronal\nholes for selected periods of x-ray observations by the Japanese Yohkoh spacecraft.\nInvestigate sources of coronal mass ejections (CMEs) using Solar Maximum Mission (SMM)\nobservations and catalogs of CMEs from Skylab.\nExamine the abrupt drop in flux noted at the end of solar maximum in the last five cycles.\nInvestigate the feasibility of combining the McIntosh and Mt. Wilson classification systems for use\nin predicting flares.\nInvestigate the application of a simple fluid jet model to the high-speed material ejected from\nmagnetic reconnection sites found in numerical MHD simulations.\nDevelop image processing and automatic feature recognition, considering such other solar features\nas coronal holes and sunspots.\nComplete a study of GOES/PHOBOS measurements from the 1989 Mars mission.\nExamine thermal energy in flaring loops in cooperation with the Space Research Center, Wroclaw,\nPoland.\nBegin a 2-year study in cooperation with the Astronomical Institute of Czechoslovakia on a possible\nscaling law for emission measure in solar flares.\nComplete a study on the diurnal and seasonal effects of energetic particles in the magnetopause on\nlow-intensity GOES x-ray data.\nIn collaboration with the Astronomical Institute of Czechoslovakia, study the possible use of a hard\nx-ray sensor on the GOES satellite to improve forecasts of SEPs.\nSupport the Max '91 observing program.\nInterplanetary Physics\nExtend the 2D IGM operational algorithm to predict increases in solar wind dynamic pressure at\nEarth following solar flares.\nCompare the catalog of synthetic all-sky maps, developed from the 3D IGM, with specific IPS\nobservations from India and England; evaluate the simultaneous data obtained from both observa-\ntories during the campaign of April-May 1992.\nPlan for the second SOLTIP symposium, to be held in Japan in June 1994.\nCollaborate with the University of Alabama in Huntsville on the merging of 3D coronal\nand\ninterplanetary MHD numerical simulations; evaluate the feasibility of using solar photospheric or\ncoronal base observations as part of initialization requirements for transient activity.\nMaintain activities with the SOHO coronagraph team and prepare for the launch of the European\nSpace Agency's SOHO satellite in July 1995.\nExtend collaboration with Indian colleagues on the IPS project only if their receivers and antenna\nsensitivity prove sufficient to detect IPS from several hundred additional radio sources.\n162","Office of the\nDirector\nJoint\nInstitutes\nSEL\nAOML\nGLERL\nFSL\nWPL\nARL\nPMEL\nGFDL\nNSSL\nCMDL\nAL\nJOINT INSTITUTES\nUnder the Joint Institutes program, NOAA and seven universities have signed Memorandums of Under-\nstanding to create Joint (or Cooperative) Institutes. The purpose is to increase the effectiveness of research\nand the quality of education in the environmental sciences by facilitating cooperation between government\nand university science. The Institutes have been a valuable vehicle for technology transfer in the many areas\nof atmospheric, oceanic, limnology, solar environment, and near-space research while also serving as a focal\npoint for multidisciplinary collaboration of research from local areas, the Nation, and the world.\nERL's seven Joint Institutes and associated universities are the following:\nCIRES\n(University of Colorado)\n(Colorado State University)\nCIRA\nCIMMS\n(University of Oklahoma)\nCILER\n(University of Michigan)\nCIMAS\n(University of Miami)\nJISAO\n(University of Washington)\n(University of Hawaii)\nJIMAR\n163","COOPERATIVE INSTITUTE FOR RESEARCH\nIN ENVIRONMENTAL SCIENCES\nBoulder, Colorado\n(303) 492-7943\nRobert E. Sievers, Director\nFounded in 1967, the Cooperative Institute for Research in Environmental Sciences (CIRES) is a joint\nendeavor of the University of Colorado and the NOAA Environmental Research Laboratories (ERL). CIRES\nacts as a research interface between ERL and University scientists, trains students and postdoctoral scientists\nin the environmental sciences, and facilitates collaborative research. The CIRES Council of Fellows\nrepresents seven University departments and two NOAA Line Offices. This report concerns research at\nCIRES that is directly relevant to NOAA missions but is funded by other agencies; NOAA funding of CIRES\nis leveraged approximately twofold by the research reported here. Additional research that is relevant to\nNOAA missions takes place in the CIRES Division of Solid Earth Sciences, including geodesic monitoring\nof sea-level rise and remote sensing of desertification processes in the High Plains of North America. This\nis described in the CIRES Annual Report.\nATMOSPHERIC AND CLIMATE DYNAMICS\nAtmospheric and climate dynamics research at CIRES is a collaborative effort with scientists at the ERL\nAeronomy Laboratory (AL), Air Resources Laboratory (ARL), Climate Monitoring and Diagnostics Labo-\nratory (CMDL), Forecast Systems Laboratory (FSL), National Severe Storms Laboratory (NSSL), Space\nEnvironment Laboratory (SEL), and Wave Propagation Laboratory (WPL). Results of this collaborative\nresearch are discussed in the individual laboratory sections. Additional sources of support include the\nDepartment of Agriculture, the Department of Defense (DOD) [through the Army Research Office (ARO)\nand the Office of Naval Research (ONR)], the Department of Energy (DOE), the Electric Power Research\nInstitute (EPRI), the Environmental Protection Agency (EPA), the National Aeronautics and Space Admini-\nstration (NASA), and the National Science Foundation (NSF).\nAccomplishments FY 92\nGlobal and Regional Climate Variability\nThe global climatology of surface-based cloud observations, which is being assembled, updated, and\nanalyzed under the auspices of the International Satellite Cloud Climatology Project (ISCCP), was extended\nto the include data for 1982-1991. The analysis of these new data is now performed at higher resolutions,\nand includes 11 cloud types rather than the previous 6. In addition, the analysis concentrated on resolving\nthe problem of possible nighttime observing bias, which would affect such results as dirunal variability of\ncloud cover. By compositing observations based on phase and altitude of the moon, it was possible to define\na threshold of irradiance above which observational bias was eliminated, and the data set was culled for\nobservations below this threshold.\n164","Joint Institutes-CIRES\nDendrochronological research continued with a digital analysis of tropical tree rings to study tropical\npaleoclimate. A field trip to northwestern Peru was made to gather tree samples, and a study of the statistical\npredictability of tree age using contemporary data was begun.\nIn collaboration with scientists at the Marine Geological Research Institute of Christian Albrechts\nUniversity (Kiel, Germany), paleogeographic analyses aimed at understanding environmental factors con-\ntrolling ancient patterns of erosion and weathering resulted in global paleographic reconstructions of two\nstages (Scythian and Carnian) of the Triassic. These reconstructions serve as boundary conditions for global\nclimate modeling studies of paleoclimate.\nModeling of the North Atlantic and its role in global climate change concentrated on the nonlinear\ndynamical rectification of variable atmospheric forcing by the ocean. Model sensitivity studies showed that\nthe evolution of the deep ocean circulation on time scales of decades depends strongly on interannual\nvariability, and that the modeled annual cycle of sea-surface temperature depends strongly on atmospheric\nvariability on the synoptic time scale (a few days). These studies used idealized variability superimposed on\na smooth forcing. The implications for climate modeling generally include the necessity to predict short time\nscales correctly if long-term evolution of climate is to be predicted correctly.\nSmall-Scale Processes and Turbulence\nThe second phase of the First ISCCP Regional Experiment (FIRE) began with an intensive field phase in\nNovember 1991 that concentrated on cirrus clouds over Kansas and continued with the Atlantic Stratocumulus\nTransition Experiment (ASTEX). CIRES involvement in the former took place mainly in collaboration with\nWPL. ASTEX studies included development of real-time color display software for quick-look data analysis\non the National Center for Atmospheric Research (NCAR) Electra research aircraft and use of the Electra to\nobtain turbulence measurements in the boundary-layer clouds in the ASTEX field phase near the Azores in\nthe eastern Atlantic.\nA study of intermittency of turbulence in the atmospheric surface layer was begun, using existing data sets\nobtained at the Boulder Atmospheric Observatory (BAO) 300-m tower. This work showed that in situ\nmeasurements of intermittency at the BAO are similar to those obtained (using research aircraft) in the marine\nsurface layer. Intermittency measurements obtained at night using lidar scintillation, a remote sensing\ntechnique, showed significant differences, which are a result of diurnal variations in plume activity.\nResearch continued on the development of a statistical (i.e., stochastic) dispersion model for passive\nscalars and pollutants in the atmospheric boundary layer (ABL) and forest canopies. In this approach, random\ntrajectories of fluid \"particles\" are followed in a turbulent flow given the turbulence velocity statistics. The\nmain advantage of the approach is the capability of dealing with complex turbulence flow fields. The model\nwas used to study dispersion of (1) passive scalars in a forest canopy, (2) scalars from point sources in the\nconvective boundary layer (CBL), and (3) buoyant plumes from tall stacks in the CBL.\nModeling of the scalar distribution in and above a forest canopy was completed for a wide range of foliage\ndensity or leaf area index (LAI). The major result was the success of the stochastic model in reproducing the\nscalar profile and derived profile properties in and above canopies. For example, the modeled temperature\nprofile was in good agreement with profiles measured in a forest and showed the expected variation of profile\nshape with LAI. For LAI greater than 2, an elevated maximum temperature occurs and increases as LAI\nincreases. Above the canopy, the profiles exhibit a well-defined, semilogarithmic shape. The predicted scalar\ngradients and roughness lengths derived from these profiles are smaller than their counterparts over short\ncanopies, e.g., grass, in agreement with field observations. These and further results will be used to develop\nimproved parameterizations of surface fluxes and profiles in climate models.\nA stochastic two-particle model was used to obtain the relative dispersion about a plume centroid and the\nroot-mean-square (rms) concentration fluctuation for point sources at various heights in the CBL. This is\n165","aimed at providing fundamental results on scalar variance for sources in the CBL-results that are very\ndifficult to obtain from field observations. The novelty of the approach is the combination of (1) the resolved\nvelocity fields from large-eddy simulations (LES) to determine the relative motion of the particles due to the\nlarge eddies in the CBL, and (2) the stochastic two-particle model to treat the random velocity of the\nsubgrid-scale eddies. The vertical inhomogeneity and skewness of CBL turbulence exist mostly on the large\nscales and thus appear in the resolved eddies. The calculations are being carried out for three boundary layer\ntypes and LES velocity fields-two strongly convective cases and a near-neutral ABL capped by an inversion.\nA hybrid dispersion model was developed earlier to describe the mean concentration field due to buoyant\nemissions from tall stacks in the CBL. This consists of (1) an entrainment model to describe the buoyant\nplume motion in the absence of ambient turbulence, and (2) a stochastic model to treat the plume centroid\nmotion caused by the turbulence. The model has been extended to predict the rms concentration fluctuation\nin plumes. Predictions have been made for weakly buoyant plumes in the CBL, and the results are in good\nagreement with laboratory data. For example, the model and data show that the fluctuation intensity at ground\nlevel is large near the source and decreases with downwind distance. This work has application to the\nestimation of peak concentrations of hazardous materials due to emissions from power plants and incinerators.\nRemote Sensing Research and Development\nIn FY 92, funding constraints at NASA had a strong effect on the development of the Earth Observing\nSystem (EOS) High Resolution Imaging Spectrometer (HIRIS) system. A scaled-back version is now under\ndevelopment; the software system development for data analysis continued as before. The aircraft version\nof this instrument, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), was used in the cirrus field\nexperiment of FIRE, and the first AVIRIS measurements of cirrus clouds in concert with a wide range of\nground-based measurements were obtained.\nStudies complementing those of the WPL lidar group included theoretical design and evaluation of\ncoherent lidar systems. The optimal design parameters for measuring atmospheric winds were determined,\nand the optimal performance of estimators of lidar signal parameters was derived. In addition, the leading-\norder effects of refractive turbulence on lidar performance were determined.\nData from the Tropical Pacific Profiler network were used to study the diurnal variation of tropospheric\nwinds. A vertically coherent diurnal oscillation in the meridional wind was found. Data analyses from the\nAntarctic profiler system were begun.\nNOAA operational satellites also provided data sets for CIRES research. Television Infrared Operational\nSatellite (TIROS) Operational Vertical Sounder (TOVS) data were used to study variations of the Arctic\ntroposphere, and comparisons with the TOVS Intial Guess Retrievals provided a cross validation of the TOVS\nsystem. A study of the TOVS water vapor channels established the value of the National Environmental\nSatellite, Data, and Information Service (NESDIS) operational \"clear/cleared column radiances\" for clima-\ntological analyses.\nPlans FY 93\nThe new observations for the global cloud climatology will be made available to the climate research\ncommunity, and comparisons with satellite-derived cloud climatologies will continue.\nRealistic forcing on short time scales will be developed for the ocean modeling studies, and the\nsensitivity of the model to this variability will be explored further.\nAnalysis of the ASTEX data set will begin, and the relationships between clouds over the eastern\nAtlantic and the eastern Pacific will be explored.\n166","Joint Institutes-CIRES\nThe canopy modeling will be extended to treat the downward transport of pollutants from the ABL\nto and dry deposition within a canopy, and the upward transport of a reactive species (hycrocarbons)\nfrom a forest canopy.\nThe two-particle stochastic model for concentration fluctuations using large-eddy simulations and\nthe stochastic model for the subgrid-scale velocities will be completed.\nCRYOSPHERIC AND POLAR PROCESSES\nResearch on global snow and ice cover in CIRES is directed toward studying the role of the cryosphere\nin the climate system, its spatial and temporal variability and the processes that link the atmosphere,\nice-covered oceans and snow/ice covered land. Much of the research involves satellite remote sensing data\nand is closely related to the data management activities of the National Snow and Ice Data Center/World Data\nCenter-A for Glaciology (NSIDC/WDC), which receives major funding from the National Geophysical Data\nCenter (NGDC) of NESDIS. A major NSIDC/WDC activity of the current year has been the development\nof the Snow and Ice Distributed Active Archive Center (SI.DAAC) for the EOS Data and Information System\n(EOSDIS). Supported by NASA, the complementary SI.DAAC has responsibility for low and medium\nresolution polar and cryospheric remote sensing data and in situ data. The data products and related science\nstudies are reported below. Glaciological field work was undertaken on the Greenland ice sheet, in Alaska,\nand in the Canadian Arctic, and snow and ice remote sensing research and development continued. NOAA\nand NASA support for Cryospheric and Polar Processes (CPP) research is complemented by support from\nNSF, ONR, EPRI, the Swiss Federal Institute of Technology-Zürich (ETH), and the National Space\nDevelopment Agency of Japan.\nAccomplishments FY 92\nData Center Activities\nThe role of the NSIDC/WDC is to acquire, archive, and disseminate data relating to all forms of snow and\nice, within the context of the guidelines for international data exchange and NOAA's mission. The latter\nmandate calls for information to assist policy formulation and decision-making regarding the oceans,\natmosphere, and coasts, and to ensure related public health and safety and national resource development.\nThese activities include the acquisition and dissemination of satellite data for polar and other snow/ice-\ncovered regions, and of other data sets that can serve as cryospheric indicators in interdisciplinary global\nchange research.\nSnow and Ice Distributed Active Archive Center\nIn 1989, NSIDC was invited to participate as one of eight DAACs in the EOSDIS. EOSDIS manages data\nfrom NASA's research satellites and field measurement programs, as well as from other data sources essential\nfor the interpretation of these measurements. It also provides access to data held in the archives of other\ngovernment agencies, organizations, and countries.\nOne of SI.DAAC's on-going products being distributed is the compact disc-read only memory (CD-ROM)\nformat of the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I)\nBrightness Temperature Grids for the Polar Regions (to date covering 9 July 1987 to 30 September 1990);\n167","associated sea ice concentration products are also distributed. A looseleaf User's Guide containing complete\ndocumentation is part of the package, along with display software for both PC and Macintosh platforms.\nDistribution of the DMSP Scanning Multichannel Microwave Radiometer (SMMR) gridded brightness\ntemperature data has been completed for 25 October 1978 to 20 August 1987. These data are in the same\nformat as the SSM/I products. Gridded sea ice concentration estimates covering 1978 to 1990 from both the\nSMMR and SSM/I data have been issued on CD-ROM. This combined data set is one of the longest satellite\nera measurements of a cryospheric parameter.\nEarth System Data and Information Management Initiative\nNSIDC began work on critical data rescue and access needs for snow and ice data. This effort has been\nfunded by the NOAA Earth System Data and Information Management (ESDIM) Initiative through NGDC.\nThere are numerous examples of data sets that are not held by NSIDC, not available to NOAA scientists, and\nalso may be at considerable risk. These include the operational sea ice data generated by the Navy/NOAA\nJoint Ice Center, instrumental snow, ice, and meteorological observations in the Antarctic, and non-U.S. data\nfrom the Arctic and Antarctic. During FY 92, a review of the entire data holding at NSIDC was carried out.\nData sets that are NOAA's responsibility were identified and are being included in the NGDC archive\nmaintenance program. Equipment was procured SO that NSIDC can use archival 3480 tape cartridges, and\nan Earth science data technician was hired to manage the archival of NOAA data at NSIDC.\nDMSP satellite data management and research\nBecause satellite passive microwave observations avoid the problems of cloud cover and polar night, they\nafford the best method to monitor temporal and spatial variations in snow cover on the hemispheric scale.\nNSIDC began development of a capability for the production of daily snow parameter products from the\nDMSP SSM/I. The data system will produce, archive, and distribute validated snow cover products for\ncommunity use. Initial emphasis was on Northern Hemisphere snow extent. The potential of the SSM/I for\nmapping other snow cover properties such as snow water equivalent, snow depth, and dry/wet snow boundary\nwas also explored. These tasks will contribute toward the production of a prototype snow cover climatology\nbased on the first 5 years of SSM/I data.\nWithin this project, NSIDC coordinated the activities of the SSM/I Products Working Team (SPWT), a\nmultiagency and multidisciplinary working group focusing on problems associated with extracting land\nsurface (primarily vegetation, soil, and snow cover) information from SSM/I. FY 92 emphasis was on\ndeveloping optimal binning, gridding, and global map projection methods, as well as selecting one or more\nsnow cover algorithms for use in distributing standardized data sets by NSIDC. A prototype version of the\nEqual Area SSM/I Earth Grids was distributed for community evaluation in July 1992. Snow cover algorithm\ncomparison and validation was begun in cooperation with several SPWT scientists. Regional test areas\nselected include the western United States, the prairie provinces of Canada, and Central Europe.\nNSIDC maintains an active collection of hard-copy transparency images from the DMSP Operational\nLinescan System (OLS) visible (0.4-1.1 um) and thermal infrared (10.4-12.5 um) sensors. The collection\nconsists of 1.5 million images providing global coverage daily from 1973 to 1991. In FY 92, approximately\n300 requests were received from the research community for these data. Although most requests are for\nimagery in support of meteorological or cryospheric studies, many requests utilize the unique ability of the\nOLS visible-band sensor to collect data under low-light conditions, providing information on biomass\nburning, city lights, lightning, auroras, and oil and gas operations.\nNSIDC continued analysis of the DMSP OLS imagery collection for the occurrence of nighttime lightning.\nLightning signatures appear as horizontal streaks on the nighttime visible-band images. This 3-year project\n168","Joint Institutes-CIRES\nis creating a data base of the time and location of lightning occurrence from the entire imagery collection.\nThis data base is being used with other data to study precipitation patterns and the global electric circuit, and\nto plan for a space platform designed to monitor lightning.\nNSIDC and NGDC began a joint program to acquire, process, archive, and distribute digital data from the\nDMSP program. In the late spring of 1992, the complete DMSP data stream began to be copied to 8-mm\nExabyte-type tapes at the Air Force receiving site in Nebraska and then shipped to Boulder. The complete\nDMSP data stream includes the OLS sensor described above, the SSM/I, a microwave sounder, and several\nspace environment sensors. NSIDC began to provide data services for the climate research community. The\narchive includes a catalog/inventory and a browse system.\nPolar Climate Processes\nPolar climate process research at CIRES/CPP includes field work, modeling, and data set analyses, which\ntake advantage of the data resources provided by NSIDC/WDC. Additional projects focus on the use of\nremote sensing data sets for understanding snow and ice variability in the Arctic.\nSnow and ice remote sensing\nSpatial patterns of mean monthly surface albedo derived from DMSP OLS satellite imagery were compared\nwith surface albedos derived from the ISCCP monthly data set. Spatial patterns of albedo obtained by the\ntwo techniques were found to be in general agreement, especially for June, July, and August. Nevertheless,\nsystematic differences in albedo in the range of 0.05-0.10 are noted. These differences are most likely related\nto uncertainties in the simple parameterizations used in the DMSP analyses as well as problems in the ISCCP\ncloud-clearing algorithm and other modeling simplifications.\nIn the past year, work concentrated on snow- and ice-surface temperature retrieval from thermal and\npassive microwave satellite data and on a monthly climatology of Arctic radiative fluxes modeled from the\nISCCP data set. Ice-surface temperature retrieval from the Advanced Very High Resolution Radiometer\n(AVHRR) using the split window channels and scan angle found that the rms error in the estimated ice surface\ntemperature is less than 1K in all seasons. Ice surface temperatures from passive microwave data appear\nto be within 5 K of buoy temperatures. Longwave radiation retrieval from the ISCCP-C2 data set seems to\nprovide useful information on the temporal and spatial variability of radiatively important parameters despite\npotential problems due to difficulties in identifying clouds in the polar regions. Longwave radiation at the\nsurface was modeled with LOWTRAN-7 for 43 case studies using radiosonde profile measurements from\nthe ETH camp on the Greenland ice sheet as input data. Comparison of modeled longwave radiation and\nground measurements showed a mean difference of 2.5 W m ² and a standard deviation of 6.3 W\nA radiation flux climatology for the Arctic was developed from the cloud product of the ISCCP monthly\n(C2) data for 1983-1986. This data set contains information on cloud fraction, cloud-top temperature and\npressure, optical thickness (visible), surface temperature, and surface spectral reflectance. There are several\ndifficulties in computing radiative fluxes from these quantities, such as the unknown geometrical thicknesses\nof the clouds, the conversion of narrow-band surface reflectances to broadband albedos, and the potential\nerrors in the cloud amounts. Directional surface albedos for snow are modeled SO that a small number of\nspectral reflectance curves can be used to represent the snow or ice surface at various times of the year. To\nverify the accuracy of cloud amounts, the ISCCP data were compared to a 30-year record of surface\nobservations and also to another satellite cloud climatology.\nThe AVHRR sensor radiances were simulated under varying atmospheric conditions to determine the\ndetectability of sea ice leads in satellite data. The simulated radiances and a statistical-geometric model of\na lead network were used to generate synthetic images with known atmospheric characteristics, and the\n169","changes in retrieved lead statistics (e.g., lead-width distributions) were examined. The effect of measurement\nscale, i.e., pixel size, was modeled as a function of the autocovariance function describing, in some sense,\nthe spatial configuration of a lead network or cloud field.\nPatterns of spring and summer snow melt and parameterized albedo over Arctic sea ice were examined\nfor 10 spring-summer seasons. These data sets are based primarily on manual charting of surface brightness\nchanges observed in visible-band DMSP imagery. Comparisons between parameterized albedo values from\nother data sets and albedos determined from the ISCCP algorithm showed good agreement between spatial\npatterns. Systematic differences of up to 0.10 occur, however, and may be due to simplification of the\nparameterization scheme, as well as inadequacies in the ISCCP cloud-clearing algorithm.\nIn a related study, the timing of spring snow melt over the Beaufort and East Siberian seas was compared\nto snow melt inferred from SMMR brightness temperatures and surface air temperature data for 1979, 1980,\nand 1984-1986. Three years (1980, 1984, and 1985) were chosen as case studies to examine relationships\nbetween snow melt and atmospheric forcings. Regional melt onset, as identified from the SMMR data, varied\nby up to 2 weeks between years, and appears to be related in part to the effects of increased cloud cover on\nthe downwelling longwave radiation flux. The subsequent pace of melt, estimated from the difference in\ndays between the SMMR signal and visual identification of melt features in the DMSP data, exhibited similar\nyear-to-year variations. Rapid melt showed some association with reduced June cloud cover, on-ice\nadvection, and high surface temperatures. However, other factors, such as variations in snow depth, as well\nas uncertainties in the data sets, appear to complicate these relationships.\nRule-based systems and neural networks were combined with remotely sensed data and physical models\nto improve mapping of sea ice conditions and to detect subtle changes in physical processes in the\nice-atmosphere system. Work has focused on using networks and other artificial intelligence methods to\nidentify spatial patterns associated with ice leads and as a \"fusion\" tool to combine passive microwave data\nand output from ice models.\nField studies\nThe objectives of the Greenland Ice Sheet Climate Programme include the study of the atmospheric\nboundary layer above the ice sheet, the study of the physical processes of the energy and mass fluxes in the\nsnow layer and at the surface, the study of the climatology of the entire Greenland ice sheet, and the use of\nsatellite and aircraft data for the interpretation of the ice surface. An ice-surface temperature retrieval\nalgorithm for the Greenland ice sheet was developed using NOAA-11 thermal radiances from channels 4\nand 5. Temperature, pressure, and humidity profiles, cloud observations, and skin temperature data from the\nresearch camp at the equilibrium line at 69° 34'N, 49° 17'W were used in the LOWTRAN-7 model. Through\na statistical analysis of daily clear sky profiles, coefficients that correct for atmospheric absorption were\ndetermined for the melting season (May to August). Surface temperatures retrieved by this method were then\ncompared to in situ observations. NOAA-11 narrow-band planetary albedo values for channel 1 and 2 were\ncalculated using prelaunch calibration coefficients. Scattering and absorption by the atmosphere were\nmodeled with LOWTRAN-7. Albedo values for the AVHRR visible and near-infrared channels then were\ncompared with in situ, high-resolution, spectral-albedo measurements. In the visible band (580-680 nm),\nAVHRR-derived, narrow-band albedo and in situ measurements corrected with a radiative transfer model\nshowed a difference of less than 2%. For the near-infrared channel (725-1100 nm), the difference between\nthe measured and modeled albedo was 14%.\nDuring May and June 1992, field studies were conducted in the Canadian Arctic as part of the Canadian\nSeasonal Ice Monitoring and Modeling (SIMM) program. Studies were primarily directed at collecting\nsurface validation data for remote sensing of surface temperature, albedo, and other sea ice properties.\nTransects of surface temperature and albedo were collected during clear sky periods near AVHRR overpasses\n170","Joint Institutes-CIRES\nover transects at a first-year site near Griffith Island, Northwest Territories, Canada. An extensive set of\nsunphotometer measurements was collected, as well as information on snow depth and hummock/meltpond\ncoverage on a large multiyear flow in Lancaster Sound.\nStructure and variability of the Arctic troposphere\nVariations in synoptic activity were assessed in terms of their potential influences on sea ice transport and\nas indicators of shifts in the Arctic atmospheric circulation related to the \"Great Salinity Anomaly\" of the\nNorth Atlantic. This extreme ice/ocean event, characterized by reductions in surface salinities in the North\nAtlantic of 0.5 to 1.0 ppt and coupled with negative water temperature anomalies and positive sea ice\nanomalies in the Greenland Sea, may be analogous to past climatic regimes in which deep water production\nin the subpolar gyres was suppressed by surface freshening.\nAnalysis of winter atmospheric pressure anomalies suggests an increased contribution to the Fram Strait\nice flux by multiyear ice from along the northern coasts of Greenland and Ellesmere Island. This may be\nrelated to a teleconnection involving changes in anticyclonic activity over the central Arctic Ocean and\nCanadian Arctic Archipelago.\nThe Historical Arctic Rawinsonde Archive (HARA), a collection of Arctic rawinsonde ascents above 65°N,\nis now available for distribution. HARA contains more than 1.2 million individual soundings, consisting of\nrecords for more than 50 stations. The archive currently extends through 1987. Data begin in the mid-1950s\nfor most stations, but go back to 1948 for some Canadian and Alaskan stations. A separate data base containing\nsoundings from the Ptarmigan aircraft overflights (1950-1961) has also been assembled. Efforts are under\nway to compile a third data base of drifting station data for the Arctic ocean.\nVariability in low-level Arctic temperature inversions may influence the transport and mixing of Arctic\npollution gases and aerosols and alter the magnitude of heat and moisture fluxes escaping from Arctic leads\nand polynyas. Nevertheless, remarkably little is known regarding spatial and temporal variability in the Arctic\ninversion layer.\nA climatology of Arctic temperatures was developed using data from the HARA data set for Arctic land\nstations above 65°N for 1976-1987, and available data for the central Arctic ocean from Soviet drifting\nstations.\nSoundings from HARA were used in a detailed analysis of Arctic tropospheric temperature trends for\n1958-1986. Time series of seasonally averaged thickness temperatures for the 850-700 mb, 700-500 mb,\n500-400 mb, and 400-300 mb layers were examined for approximately 50 stations. Although the results\nindicate regionally coherent temperature trends for all layers, particularly during winter, no general warming\nduring the study period can be attributed to increasing concentrations of greenhouse gases.\nA simple, fetch-dependent boundary-layer model was used to examine theoretical heights of buoyant\nconvection above open leads in the winter Arctic pack ice cover. The model was applied to a suite of sounding\ndata from Soviet drifting stations, assuming open-water leads of 100 m, 1000 m, and 10,000 m. The depth\nof convection increases with increasing lead width. Although the depth of convection shows large variability,\nevents of convection up to 4 km, as observed from lidar backscatter data, are likely to be uncommon. First,\nthese events require an open water lead of least 10,000 m. Second, although the conditions most conducive\nto deep convection are a combination of large air-sea temperature differences, low wind speeds and a weak\nlow-level temperature inversion, this combination appears to be atypical of Arctic conditions. Finally, the\nconditions most suitable for deep convection are also those in which any newly formed leads will quickly\nice over.\n171","Plans FY 93\nNegotiations between NSIDC and the Federal Records Center will be completed, and the DMSP\nimagery collection will be moved to that Center.\nNegotiations with NGDC will be concluded and the DMSP digital archive will become an official\nNESDIS program.\nA workshop will be held in the spring of 1993 to prioritize snow and ice data to be rescued.\nNSIDC is still receiving data sets from investigators in the Coordinated Eastern Arctic Experiment.\nThese and other eastern Arctic ice-related data will be proposed for future volumes in the CD-ROM\nseries.\nEfforts to acquire funding to perform additional Canadian Arctic field measurements during the\nspring of 1993 will continue.\nField expeditions to the Greenland ice sheet station are planned for 1993 and 1994 to continue climate\nrecording and experimental field measurements for satellite calibration.\nInterannual and seasonal variations of different surface parameters and energy fluxes will be analyzed\nfor the entire Greenland ice sheet for the past 10 years. This data set will be used as baseline data to\ndetect deviations from the climate norm.\nRadiative fluxes for two Arctic experiments, in the Beaufort Sea and in the Canadian Archipelago,\nwill be estimated, and parameterizations for these fluxes will be developed.\nApplication of the parametrization schemes to basin-wide energy balance estimates using remote\nsensing data will be tested.\nENVIRONMENTAL CHEMISTRY AND BIOLOGY\nCIRES environmental chemistry and biology research includes wide-ranging collaborations with AL and\nCMDL, which are discussed in the Laboratory sections of this document. Work discussed here is funded by\nNSF, DOE, EPRI, and the Chemical Manufacturer's Association.\nAccomplishments FY 92\nGlobal Change\nStudies continued on an ambitious data collection program for methane flux from the Orinoco flood plain\nin Venezuela. Methane fluxes from tropical flood plains are a potentially significant component in the global\nmethane budget because these flood plains are highly active metabolically, contain extensive anaerobic\norganic deposits, and cover large areas adjacent to the large tropical rivers. Extensive vegetation mats on\nthe river, which account for as much as 50% of the area of inundated flood plain, can enhance methane release\nbecause they create pockets of anaerobic conditions, and because the aquatic plants conduct methane at the\nsurface quickly, thus preventing it from being oxidized near the surface before leaving the water column. In\nFY 92, measurements of methane fluxes in the Orinoco River basin were completed. Data analyses began\nto provide a sound basis for estimating the total methane release for the Orinoco flood plain.\nCIRES scientists are investigating the use of high spectral resolution optical and infrared spectra for\nestimating plant-canopy chemistry and biophysical properties that control biogeochemical cycling. Results\n172","Joint Institutes-CIRA\nobtained using plant material and reflectance spectra collected at the Konza Prairie, Kansas, and in Colorado\ngrasslands indicated that foliar chemistry affects the leaf reflectance spectrum in detectable and quantifiable\nways. Temporal studies of light interception and reflectance, gas exchange, and nitrogen allocation were\nconducted using imagery from the AVIRIS spectral and spatial analyses of the landscapes of these grassland\nand shrubland study sites.\nRegional Environmental Problems\nDevelopment of a new technique to measure carbonyl compounds, which are ozone precursors, in the\natmosphere continued. The technique is based on the simultaneous collection and derivatization of these\naldehydes and ketones on microcartridges containing porous glass beads impregnated with dansyl hydrazone\n(DNSH). Measurements of sub-ppbv levels of formaldehyde, acetaldehyde, and some higher carbonyl\ncompounds were made at Niwot Ridge, Colorado, during the summer of 1991. The high sensitivity of the\ntechnique suggests the possibility of future measurements of formaldehyde in the free troposphere. FY 92\nresults achieved a tenfold increase in sensitivity.\nCIRES scientists continued to work to develop a more mechanistically based algorithm for leaf isoprene\nemission, and to test this algorithm with field measurements. Isoprene emission rates from individual trees\nwere investigated with a laboratory gas exchange system and an environmentally controlled leaf cuvette. FY\n92 activities included extension of both laboratory and field studies to the emission of methanol from a variety\nof leaf surfaces, and it was discovered that methanol emissions occur at rates similar to those of isoprene.\nPlans FY 93\nAnalysis of data from the Orinoco flood plain will be completed, and the role of various links in the\nfood chain in controlling the carbon cycle will be elucidated.\nAdequate spectral resolution needed to determine canopy and rangeland biomass will be assessed,\nand alternate design for satellite instruments will be investigated.\nThe carbonyl detector will be used in field studies to determine if its use in the free troposphere is\nfeasible.\nThe biochemical processes responsible for the emission of methanol from plant leaves will be studied\nin detail.\nCOOPERATIVE INSTITUTE FOR RESEARCH IN THE ATMOSPHERE\nFort Collins, Colorado\n(303) 491-8448\nThomas H. Vonder Haar, Director\nThe Cooperative Institute for Research in the Atmosphere (CIRA) was formed in 1980 between Colorado\nState University (CSU) and NOAA to increase the effectiveness of atmospheric research of mutual interest\nto NOAA, CSU, Colorado, and the nation. CIRA operates under the auspices of the CSU Graduate School\nand its Office of Vice President for Research. Its objectives are to provide a center for cooperation in specified\nresearch programs by scientists from Colorado, the nation, and other countries, and to enhance the training\nof atmospheric scientists. All CSU and NOAA organizational elements are invited to participate in CIRA's\n173","atmospheric research programs. Participation by NOAA is primarily through the Environmental Research\nLaboratories (ERL), the National Environmental Satellite, Data, and Information Service (NESDIS), and the\nNational Weather Service (NWS). At CSU, the Departments of Atmospheric Science, Civil Engineering,\nComputer Science, Earth Resources, Economics, Electrical Engineering, Physics, Psychology, Recreation\nResources and Landscape Architecture, and Statistics have been or are involved in CIRA activities. CIRA\nresearch concentrates on air quality, cloud physics, mesoscale studies and forecasting, satellite applications,\nclimate studies, agricultural meteorology, model evaluation, and the economic and societal aspects of weather\nand climate.\nAccomplishments FY 92\nEach year CIRA hosts a workshop for all CIRA research personnel. This year's research workshop was\nheld 3-5 June 1992 and was well attended by many CIRA researchers, which includes employees of CIRA,\nCSU, and Regional and Mesoscale Meteorology (RAMM) branch of NESDIS, and students whose research\nis supported by CIRA. The purpose of the research workshop is to encourage new thought and explore new\nconcepts of existing research.\nA very successful Fellowship Program supported scientists from various countries. Many prominent\nscientists also visited CIRA and gave seminars.\nPlans FY 93\nContinue to cooperate with the U.S. Army Research Office through the Center for Geosciences.\nCIRA will also hold a general research workshop and an invitational workshop.\nContinue its Fellowship Program with the scientists from the United States and other countries, host\nvisiting scientists, and support the seminar program.\nSATELLITE CLOUD CLIMATOLOGY PROJECT\nAccomplishments FY 92\nCIRA participates in the International Satellite Cloud Climatology Project (ISCCP) (part of the World\nClimate Research Programme) as a Sector Processing Center. Major accomplishments included the following:\nPrepared high-resolution cloud estimates from Indian Satellite (INSAT) data.\nCompleted the INSAT review and reformatting.\nProvided a large, very user-friendly, structured cloud data set.\nParticipated in several regional cloud observing experiments such as the First ISCCP Regional\nExperiment (FIRE)/Atlantic Stratocumulus Transition Experiment (ASTEX) and International Cir-\nrus Experiment (ICE).\n174","Joint Institutes-CIRA\nPlans FY 93\nExamine cloud forcing of vertical cloud distribution.\nComplete the INSAT review and reformatting.\nCompare ISCCP C1 products and sea-surface temperatures (SST).\nCollect and archive ISCCP B1 and B2 data from GOES West with the 4.5 years of ISCCP data (March\n1983-December 1987).\nCollect METEOSAT-3 (European Space Agency weather satellite) data.\nModify CIRA's Earthstation by adding a Domestic Satellite (DOMSAT) Satellite Communications\n(SATCOM) F2R capability.\nSEVERE WEATHER RESEARCH\nAccomplishments FY 92\nStudies supported NOAA's severe weather prediction mission in mesoscale analysis and forecast product\ndevelopment.\nContinued to interact with NOAA elements on TIROS data uses, mesoscale soundings with Visible\nand Infrared Spin-Scan Radiometer (VISSR) Atmospheric Sounder (VAS) data, and expert system\nforecasting regions.\nContinued to utilize expert system forecast (nowcast) applications in continued interactions with the\nCheyenne, Wyoming, NWS Forecast Office.\nContinued to evaluate several Oklahoma-Kansas Preliminary Regional Experiment for Stormscale\nOperational and Research Meteorology (OK-PRE-STORM) data sets.\nContinued to transfer information through publications, seminars, training programs, and CIRA\nresearch retreats.\nContinued to transfer software to the NWS National Severe Storms Forecast Center in Kansas City,\nMissouri, to aid in analyzing rapid-scan imagery through storm-relative animation.\nContinued to transfer software to the National Severe Storm Forecast Center, the National Hurricane\nCenter, and the Satellite Data Analysis Branch located at National Meteorological Center (NMC),\nWashington, D.C., to aid in the analysis of satellite data.\nParticipated in the Cape Kennedy Precipitation Experiment (CaPE) by providing nowcasting\nexpertise for satellite data analysis at the CaPE Operations Center.\nPlans FY 93\nContinue to investigate satellite data focused on severe convective environments.\nContinue to investigate satellite data focused on tropical storms and mesoscale convective systems.\nContinue to use satellite data and enhanced mesoscale data sets for improved mesoscale analyses\nand nowcast product development.\n175","Investigate independent VISSR ingest systems for real-time, simultaneous GOES mode AAA data.\nInvestigate communication links with NOAA/NESDIS VDUC system, and PROFS and NCAR\nmeteorological data bases.\nDevelop powerful image display and processing system, including a RISC workstation.\nDevelop a compatible microprocessor system to access and store VAS-derived product files from\nthe University of Wisconsin's computer facility.\nContinue to develop mesoscale training aids and techniques.\nAIR QUALITY-JOINT RESEARCH\nWITH THE NATIONALPARK SERVICE\nAccomplishments FY 92\nA cooperative effort with the U.S. National Park Service (NPS) and NOAA continued to determine,\nevaluate, and analyze the visual effects of pollutants on specific scenic vistas.\nEstimated aerosol acidity at NPS Interagency Monitoring of Protected Visual Environments\n(IMPROVE) data collection sites to determine the feasibility of modifying the samplers to allow a\nmore conventional measurement of aerosol acids.\nConducted a study to test and validate the backward-scattering Monte Carlo radiative transfer model.\nDeveloped a particulate database management system that incorporates outlier checking, quality\nassurance, periodic summarization, and statistical analysis.\nProcessed national park ozone data and developed and ran Atmospheric Transport and Dispersion\n(ATAD) model back-trajectories to identify source regions contributing to high concentrations of\nozone in national parks.\nDetermined the acidity of sulfate aerosols at Shenandoah, Great Smoky Mountains, and Acadia\nNational Parks.\nIdentified reasons for differences between reconstructed and measured fine particle mass and light\nextinction.\nAnalyzed data from Mount Rainier Pacific N.W. Regional Visibility Experiment Using Natural\nTracers (PREVENT) study using correlation and factor analysis of trace elements, constructed time\nseries and contour plots, and performed trajectory models.\nProvided graphics and video support to the NPS air quality division and to CIRA.\nCompleted a NPS management training video depicting sources and types of pollutants that impact\nspecific national parks.\nPlans FY 93\nInstall and test a new 32-bit video graphics system that will provide a method to mix video signals\nand special effects graphics.\nProduce a training video on the use and calibration of visibility monitoring equipment.\n176","Joint Institutes-CIRA\nProduce an interpretive video for Sequoia National Park showing the effects of air pollution on fauna.\nProduce a video showing the biological effects of pollutants on fauna in national parks for the NPS\nregional office in Denver.\nDevelop photographic imaging techniques that will accurately depict slight changes in visibility due\nto layered and regional haze.\nDevelop a series of reports that summarize the results of recently completed investigations of the\napplicability of various radiation transfer models as they apply to real-world situations.\nDevelop and use receptor models to determine transport pathways and estimate the proportion of a\nmeasured pollutant that can be attributed to each of several sources.\nInvestigate the effect that various sulfur emission reduction scenarios would have on visibility.\nWMO SHARE PROGRAMME\nCIRA contracted with the World Meteorological Organization (WMO) to participate in the WMO Software\nHelp in Applications, Research, and Education (SHARE) Programme. SHARE is a 3-year international\nproject to develop meteorological analysis and display software for participating countries and to train\nscientists of these countries in the use of SHARE products. Scientists from Argentina, Brazil, Jamaica, Kenya,\nMauritius, Niger, Pakistan, People's Republic of China, Poland, Sri Lanka, Trinidad, Turkey, Venezuela, and\nYemen visited CIRA the last four years.\nAccomplishments FY 92\nContinued to assist participating countries in training and in installing the VAX VMS Version 1.0\nsoftware produced by CIRA to enable scientists to instruct others in use of an IBM PC/AT for specific\nresearch needs.\nContinued to provide software routines to participating countries to process and display forecast\nproducts.\nPlans FY 93\nWork on the Data Receiving System/Meteorological Data Distribution (DRS/MDD) point-to-\nmultipoint data link.\nProvide \"maintenance\" work to clean up software and hardware problems in countries that are using\nthe SHARE workstation software.\nEvaluate the Chinese weather software package using the SHARE workstation.\n177","COOPERATIVE INSTITUTE FOR MESOSCALE\nMETEOROLOGICAL STUDIES\nNorman, Oklahoma\n(405) 325-3041\nPeter J. Lamb, Director\nThe University of Oklahoma (OU) and NOAA established the Cooperative Institute for Mesoscale\nMeteorological Studies (CIMMS) in 1978 to promote cooperation and collaboration on problems of mutual\ninterest among research scientists in the NOAA Environmental Research Laboratories, mainly the National\nSevere Storms Laboratory (NSSL), and faculty, postdoctoral scientists, and students in the School of\nMeteorology and other academic departments at OU. Through CIMMS, OU faculty and NSSL scientists\nalso collaborate on research supported by other NOAA programs and laboratories as well as other agencies\nsuch as the National Science Foundation (NSF) and the Federal Aviation Administration (FAA).\nA 3-year cooperative agreement between OU and NOAA for CIMMS funding took effect on 1 July 1990.\nUnder this agreement, CIMMS concentrates its efforts and resources on three principal research themes:\n(1) basic convective and mesoscale research, (2) forecast improvements, and (3) climatic effects of mesoscale\nprocesses.\nREGIONAL WEATHER PROCESSES\nAccomplishments FY 92\nStudies of the large-scale environments that produce nighttime rainfalls at Omaha, Nebraska, continued\nthrough the year. Results indicate that pronounced synoptic signals, i.e., significantly different from\nclimatology, precede the events by 6 to 18 h. The results should improve National Weather Service (NWS)\nforecasting procedures in the central United States. These studies involved NSSL staff and CIMMS graduate\nstudents.\nVarious data sets gathered during the Southwest Area Monsoon Project (SWAMP) observational period\nin 1990 were used to study and document thunderstorm environments over Arizona. Specifically, the\nlarge-scale settings that bring severe thunderstorms (principally damaging wind storms and flash floods) to\ncentral Arizona were studied. Three distinct patterns were identified, and one severe case was examined in\ndetail. These studies also involved NSSL staff and CIMMS graduate students.\nPlans FY 93\nExecute a small, collaborative data-gathering exercise in central Arizona and also northwestern\nMexico. This field work will obtain follow-on data to enhance the SWAMP data bases. It will focus\non WSR-88D assessments in the Phoenix area and on research data gathering in Mexico. Collabo-\nrators will include CIMMS, the NWS Western Region and Phoenix, Arizona State University, the\nUniversity of Arizona, the Mexican Weather Service, and the Salt River Project. This effort will\nsupport a second phase of the studies of thunderstorms in Arizona.\nInitiate a collaborative modeling effort by CIMMS and NSSL's Regional Weather Processes Group.\nThis work will focus on simulation studies at both the storm and mesoscale to relate the mode of\n178","Joint Institutes-CIMMS\norganization of convective storms to subsequent feedbacks to radiative forcing. This work will be\npart of the Department of Energy's Atmospheric Radiation Measurement (ARM) Program's Southern\nPlains Cloud and Radiation Test Bed (CART) site science activities, which are centered at CIMMS.\nComplete the studies of central United States nighttime rain events and present the results at the NWS\nCentral Region Headquarters in Kansas City.\nSTORM ELECTRICITY\nAccomplishments FY 92\nCIMMS scientists and graduate students continued research on the electrical aspects of mesoscale\nconvective systems (MCSs) using unique data obtained from instrumented balloons, a NOAA P-3 aircraft,\nand Doppler radars. An expert in balloon-borne measurement of electric fields and precipitation particles\nfrom the University of Mississippi spent his sabbatical as a CIMMS Visiting Research Scientist. A significant\namount of analysis from the Cooperative Oklahoma Profiler Studies-1991 (COPS-91) field program was\nperformed by a team comprising scientists and students from CIMMS, OU School of Meteorology, and\nNOAA.\nA CIMMS graduate student continued research to obtain in situ measurements of precipitation particle\ncharge and size. Preliminary analysis of the precipitation particles from several MCSs shows features key\nto the understanding of electrification mechanisms and the role of charge on precipitation in accounting for\nthe electric field. For example, the percentage of precipitation that carries detectable and significant charge\nis often very low, affecting the efficacy of charge generation by collisional charging.\nIn other areas, modeling efforts to incorporate electrical effects in storms and MCSs continued as\na\nmultiyear, collaborative project between CIMMS, OU School of Meteorology, and NSSL. A high-speed\nvideo of lightning was taken in an FAA-related project in Orlando, Florida.\nPlans FY 93\nContinue to analyze data from COPS-91 to assess precipitation charge structure and its relationship\nto total charge in MCSs, and to document and assess differences in the electrical structure of MCSs\nwith a linear versus bow-echo leading line/trailing stratiform regions.\nContinue the electrical modeling project, and submit proposals to fund analysis of the remarkable\nhigh-speed video lightning data from Florida.\nGUFMEX\nAccomplishments FY 92\nTen articles related to GUFMEX 1988 have been published.\nA master's thesis was prepared on return flow and equilibrium models.\n179","Plans FY 93\nSubmit a joint proposal through the cooperative institutes at OU, Texas A&M University, and the\nUniversity of Wisconsin (UW) to conduct more field work in 1994. The proposal will include\nemphasis on understanding the air, sea, and land topographic effects on return flow in the northwest\nGulf of Mexico. We will also address the hydrological cycle issue along the Gulf coastal plain and\nthe lower Mississippi basin.\nCoordinate modeling studies with the National Meteorological Center (NMC) and UW to determine\nthe impact of data from the Gulf of Mexico and air-sea interaction processes on cool season\nprecipitation forecasting.\nContinue modeling studies with OU collaborators to employ a diagnostic model to study topographic\neffects on the low-level jet and on cloud modeling in return flow situations.\nFocus operations research with CIMMS and the National Severe Storms Forecast Center on synoptic\nanalysis of the March 1991-1992 return flow events and NMC forecasting of the same.\nPerform other operations research with UW and the NWS Slidell office using a Special Sensor\nMicrowave/Imager (SSM/I) to determine the moisture transported in return flow events.\nDATA ASSIMILATION\nAccomplishments FY 92\nWe collaborated with the OU Computing Sciences Institute on parallel processing applied to the problem\nof hurricane track prediction. A paper on Hurricane Elena 1985 was submitted for publication.\nA Ph.D. dissertation on parallel processing applied to deterministic prediction in meteorology was\ncompleted.\nCourses on meteorological data assimilation for computer scientists were developed and offered to\ngraduate students at OU in Meteorology and Computer Science.\nCollaboration with scientists at PSU has produced a paper on nonhydrostatic modeling and data assimi-\nlation.\nPlans FY 93\nSubmit a proposal in collaboration with OU Computer Science Institute, Atlantic Oceanographic and\nMeteorological Laboratory (AOML)/Hurricane Research Division, and NSSL to apply parallel\nprocessing strategies to hurricane problems.\nWork with the OU Mathematics Department to develop assimilation methods applicable to meteor-\nology models.\n180","Joint Institutes-CIMMS\nCLOUD MODELING WITH DETAILED MICROPHYSICS\nAccomplishments FY 92\nWarm Cloud Modeling\nThe mechanisms of vortex formation as a result of cloud merger were analyzed, with special attention to\nthe role of vorticity. The cloud merger process was studied theoretically and in three-dimensional numerical\nsimulations, and cloud merging time from the numerical results was in good agreement with the hydrody-\nnamical theory.\nAnalysis of the condensation process in both maritime and continental clouds was performed employing\ndata from a model that explicitly formulates cloud microphysics. Based on this analysis, the limits of\napplicability of the moist adjustment scheme was determined, and an improved parameterization of the\ncondensation has been proposed.\nA Lagrangian air parcel model with a highly resolved cloud droplet distribution function was employed\nto study the nucleation process. A parameterization appropriate for stratocumulus cloud models that accounts\nfor aerosol activation and the solute effect in condensational growth has been proposed.\nDevelopment of a Thunderstorm Model\nAn improved dynamical framework for a new convective cloud model was developed, providing the\nfoundation for future inclusion of detailed ice-phase microphysics.\nStratocumulus Cloud Modeling\nA stratocumulus cloud model based on a three-dimensional large eddy simulation with explicit formulation\nof cloud microphysics and long wave radiation was developed. Preliminary experiments established the\nmodel's performance, and sensitivity experiments illustrated the importance of cloud droplet recycling. Work\nis under way to include the effects of solar radiation and the effect of regeneration of cloud nuclei.\nPlans FY 93\nStudy mechanisms of warm rain initiation and evolution in tropical convective clouds, and investigate\nthe composition and history of various cloud elements using trajectory analysis. The major focus\nwill be on understanding the role of mixing and cloud-top entrainment mechanisms in producing\nspatial inhomogeneities in cloud microstructure that may facilitate rain formation.\nContinue development of a thunderstorm model with the design, coding, and testing of an ice-phase\nmicrophysical block. The model will also be tested as a whole in a multidimensional dynamical\nframework, and sensitivity experiments will focus on the role of individual ice nucleation processes\nin precipitation formation. This work will be a collaborative effort with a scientist from the Central\nAerological Observatory in Moscow; participation of two other scientists from the Hebrew Univer-\nsity in Jerusalem is also anticipated.\n181","Investigate further the interaction between atmospheric aerosols, a stratocumulus cloud layer, and\nradiation in a set of experiments studying the effect of various aerosol distributions on cloud\nthermodynamical and radiative properties.\nStudy the sensitivity of the model results to different parameterizations of cloud microstructure, with\nan eye toward evaluation of the accuracy of microphysical parameterizations in global circulation\nmodels.\nMESOSCALE DYNAMICS, PHYSICAL PROCESSES, AND MODELING\nAccomplishments FY 92\nDensity Currents in Shear Flows\nThe classic theory of density currents was extended to include the effects of environmental shear and\nnegative vorticity generation along the interfacial layer between the density current and the environmental\nflow. The physical insights gained concerning the interaction between the shear and the cold pool were\nreported in two publications.\nExamination of the Impact of Neglecting the Mass Sink Term\nThe term in the continuity equation that accounts for the mass sink of moist air due to condensation is not\nalways negligible, but it has been neglected in many numerical models. The Pennsylvania State Univer-\nsity/National Center for Atmospheric Research (PSU/NCAR) mesoscale model was employed in a series of\nexperiments examining the effect of inclusion of this term, and the results (presented at a conference and\naccepted for publication) show that this term can have a significant impact on heavy precipitation forecasts.\nExperimental Studies of Cold-Air Damming\nScientists at CIMMS and the Department of Civil Engineering, University of Dundee, United Kingdom,\ncollaborated to test earlier theoretical work on cold-air damming by simulating the process in a laboratory\nrotating tank. The observed two-dimensional structures were in good agreement with the theory, and the\nresults were presented at a conference on mountain meteorology.\nReexamination of the Q-vector Equations in Three Dimensions\nThe Q-vector equations were combined with the vertical ageostrophic vorticity equation to create a\ncomplete set of vector quasi-geostrophic diagnostic equations. This reformulation introduces a new geostro-\nphic forcing vector, termed the C-vector, that shows merit for both qualitative analyses and quantitative\ncomputations of three-dimensional ageostrophic circulations. The C-vector formulation and methods of\nsolution were also extended to the semigeostrophic equations in physical space. This work was reported at\ntwo conferences and in one journal.\n182","Joint Institutes-CIMMS\nStudy of the Psi-Equations\nThe completeness of the solution for three-dimensional ageostrophic circulations solved from the\npsi-equations and the admissible boundary conditions were addressed, methods of solution were proposed,\nand extended research was conducted by scientists at CIMMS, the State University of New York at Albany,\nand NSSL. Examples showing the possible significance and physical implication were presented in two\npublications.\nConstruction of a New Semi-Balance Intermediate Model\nBecause intermediate models take only a fraction of the computational time required by primitive-equation\nmodels, they are considered an alternative for long-period simulations of climate models. By examining the\nproblems and advantages of the existing intermediate models, a new type of intermediate model was derived\nfor slowly evolving nonlinear flows that should be applicable to vortices and fronts over a wide range of\nRossby numbers. These results were presented at a conference and submitted for publication.\nQuasi- and Semi-Geostrophic Diagnostic Models\nThe three-dimensional, viscous, semi-geostrophic (VSG) diagnostic model was further developed for\nreal-data uses by including topography, a horizontal adjustment scheme for inertial instability, a slantwise\nadjustment scheme for moist symmetric and convective instability, explicit computation of stratiform latent\nheating, and bulk formulations of eddy viscosity and boundary layer processes. The model was tested on\nboth real and simulated data, and the results (reported at two conferences) were significantly better than the\nconventional omega-equation model. The VSG model was then used for two case studies by scientists from\nCIMMS, NSSL, and NOAA/National Environmental Satellite, Data, and Information Service (NESDIS).\nSingle Doppler Wind Analysis\nSimple-adjoint methods were developed for retrieving the time-mean winds for a period covering several\nconsecutive scans from a single Doppler radar. The methods were tested on experimental data, and were\nvery encouraging. Comparisons were also made between the simple-adjoint methods and other existing\nmethods of the same category. Because of its low computational cost and high accuracy, the simple-adjoint\nmethod is believed to be the most promising for near-future operational use. This work was presented at a\nconference and submitted for publication.\nPlans FY 93\nStudy the 6-7 May 1985 storm, concentrating on further improvements of the diabatic initialization\nmethods based on balanced diagnostic equations, to improve understanding of the dynamics and\nphysical processes in MCSs.\nContinue to examine the quasi-two-dimensional structures along and upstream of a ridge revealed\nin laboratory observations and analytical and numerical simulations.\nExtend the recently developed theory of density currents in sheared flows to examine the effect of\ninternal circulation within the cold pool.\n183","Improve the VSG model based on the recent developments in Q-vector, C-vector forcing, and\nsemi-balanced model formulations.\nExpand single Doppler wind analysis work to improve it and apply it to a wider range of data.\nDevelop and test an adjoint column model against data acquired by the ARM Program, to examine\nand improve cumulus parameterization schemes employed in global circulation models.\nCLIMATE DIAGNOSTICS\nAccomplishments FY 92\nData Set Development\nFollowing the extension of the Lamb-Richman high resolution daily rainfall data to include all calendar\nmonths and a larger area (the United States from the Rocky Mountains to the Atlantic Ocean, and from 55°N\nto the Gulf Coast), a companion data set of maximum and minimum temperatures with the same spatial\nresolution and areal extent was created.\nRelationship Between El Niño-Southern Oscillation and North American Precipitation\nResults confirmed earlier findings and revealed several new North American coherent precipitation regions\naffected by the El Niño-Southern Oscillation (ENSO) in the central Pacific. This research is the basis for an\nundergraduate honor's thesis at OU.\nNorth American Storm Track Precipitation Signatures\nThis ongoing effort seeks to define the precipitation signatures associated with pressure-based cyclone\ntracks during the cool half of the year. Several surprising features were documented, including precipitation\nsignatures for the Alberta Storm track in the northern tier of the United States/southern Canada (expected)\nand an equally large signal (~5 mm per day) in the southeastern United States. The latter was found to be\nrelated to moist air from the Gulf of Mexico overrunning old frontal boundaries.\nAtmospheric Moisture Budget of Central North America\nWe continued to quantitatively investigate the atmospheric budget of a 106 km2 area that extends from\neastern Nebraska-Kansas to eastern Ohio and from central Wisconsin-Michigan to the southern borders of\nMissouri and Kentucky. This work is focusing on the contrasting growing seasons (May-August) of 1975,\n1976, 1979, and 1988. It is examining the interrelations between the moisture budget components and\nassessing the relative importance of imported versus locally evaporated moisture for the growing season\nrainfall.\n184","Joint Institutes-CIMMS\nImpacts Studies\nSubsets of precipitation data were used for climate impacts research to match the impact spatial scale to\nthe climate scale. A hydrological impacts study that documents the surface water, groundwater, and climate\nfluctuations over several watersheds in Illinois was conducted by scientists at CIMMS and the University of\nStirling, United Kingdom, and the results were submitted for publication.\nPlans FY 93\nPublish journal articles documenting the coherencies in central North American precipitation as a\nfunction of month and integration period.\nInvestigate the synoptic relationships between geopotential height patterns in four dimensions and\nthe mean and evolution of the coherent areas of precipitation.\nPublish journal articles containing the key results from the ENSO, storm track, and moisture budget\nwork.\nCLIMATE MODELING\nAccomplishments FY 92\nOutput from two global circulation models with high spatial and temporal resolution (Geophysical Fluid\nDynamics Laboratory's R30 daily runs and the Max Plank Institut für Meteorologie, Hamburg, Germany,\nT42 model daily control runs) was assembled to complement our climate database.\nPlans FY 93\nPlan collaborative work with the Max Plank Institut für Meteorologie. A CIMMS scientist will also\npresent several statistical seminars there. Discussions are expected to include statistical diagnosis\nof climate models, detection of climate change, and the determination of the statistical dimensionality\nof the atmosphere.\nInitiate collaborative research on \"optimal fingerprinting\" techniques (a method for identifying global\nchange) with Lawrence Livermore Laboratory.\n185","MULTIVARIATE STATISTICS\nAccomplishments FY 92\nMultivariate statistical techniques, such as various cluster analysis (CA) algorithms, were applied in a large\nsimulation to determine their regionalization properties. A summary of the CA regionalizations of North\nAmerican rainfall was presented at two conferences, and a journal article was submitted.\nResearch into eigenvector methodology included the effects of domain shape, orthogonality, and maximum\nvariance on principal component patterns. Results indicate the above factors need to be seriously considered\nbefore physically interpreting the eigenvectors.\nCollaborative work between scientists at CIMMS and the Meteorological Institute of Liaoning Province,\nPeoples Republic of China, focused on transferral of the eigenvectorial regionalization methodology to the\ndivision of northeastern China into homogeneous precipitation areas.\nA multivariate technique new to atmospheric sciences (Procrustes Target Analysis, PTA) was applied to\natmospheric chemistry data from the western United States. Results indicated that sources of sulfur emissions\ncould be better identified using the PTA compared to more traditional statistical techniques.\nDetermining the most appropriate dimensionality in multivariate statistics has long been a source of\nconsiderable controversy. Recent research was undertaken to review and synthesize the geophysical and\nstatistical literature to determine how investigators were approaching the problem. Twenty \"tests\" were found\nand compared over a range of conditions, revealing large biases in certain tests.\nA joint CIMMS/NSSL/OU project was initiated to characterize severe weather outbreaks using four-\ndimensional statistical analyses with parallel eigenanalysis algorithms. Test data have been assembled to\nobtain detailed timings on eigenanalysis of a 4096 square matrix.\nPlans FY 93\nContinue large intercomparison and review of dimensionality work and publish results.\nSubmit a proposal for a more extensive CIMMS/NSSL/OU project on four-dimensional charac-\nterization of severe weather outbreaks.\nCollaborate with scientists from the Max Plank Institut für Meteorologie and Lawrence Livermore\nLaboratory on statistical aspects of detecting climate change and diagnosing it in global circulation\nmodels.\nATMOSPHERIC RADIATION MEASUREMENT PROGRAM\nAccomplishments FY 92\nCIMMS began to perform its \"Site Scientist\" role for the Southern Great Plains portion of the international\nprogram operated by the U.S. Department of Energy. This involved participating in many planning meetings,\nand assisting with the establishment and early operation of the central observing facility near Lamont,\nOklahoma, and with the initiation of a broad-based research program. This research program is investigating\n186","Joint Institutes-CIMMS\natmospheric radiative transfer and the surface radiation balance, cloud-radiation interactions, convective\nprocesses, lower tropospheric studies, and spatial and temporal analyses of cloudiness and soil moisture.\nPlans FY 93\nOversee the development and implementation of calibration and diagnostic procedures of the\ninstruments across the entire observational facility, including the central, auxiliary, extended, and\nboundary installations.\nParticipate in directed workshops and begin research based on data from the facility.\nFORECAST APPLICATIONS RESEARCH\nAccomplishments FY 92\nGust Front Detection Algorithm\nWe enhanced the Gust Front Detection and Wind Shift Prediction Algorithms developed for the FAA's\nTerminal Doppler Weather Radar (TDWR) program. Studies were completed to determine the relative\nlocation of the reflectivity thin line and the corresponding surface wind shift associated with gust fronts. The\nreflectivity thin line on average is 2 km behind the surface wind shift.\nVertical Wind Shear Estimation\nWe developed a technique that uses Doppler radar velocities to estimate the vertical shear of the horizontal\nwinds at low altitudes. Strong vertical wind shear at low altitudes can be dangerous to landing aircraft. We\nalso investigated the use of the output of this technique to remove false alarms in the gust front detection\nalgorithm caused by strong vertical wind shear.\nData Base Development\nWe developed a data base of more than 30 h of Doppler radar data, which was perused by radar\nmeteorologists to determine the location of storm cells, and mesocyclone and tornado signatures. Severe\nweather reports were collected for these same times. A technique was developed and software was written\nto automatically determine the performance of algorithms designed to detect these phenomena. This data\nbase will be used to test, compare, and refine future NEXRAD and TDWR algorithms.\nTesting Algorithms in Different Environments\nAlgorithms that track storm cells and detect hail, tornadoes, and mesocyclones were tested using data from\nOklahoma, Colorado, and Florida to determine the performance of the algorithms in the different environ-\nments and to determine what changes are needed to perform well in the different environments.\n187","Plans FY 93\nDevelop a new technique to dealias Doppler radar velocities in the clear air.\nRefine algorithms that detect hail, mesocyclones, and tornadoes to ensure they perform well in all\nenvironments and on differing radar systems (e.g., NEXRAD, TDWR).\nConduct studies to investigate how well different models [the operational Nested Grid Model (NGM)\nand the Eta model] perform in determining the return of warm moist air off of the Gulf of Mexico\nafter cold frontal passage.\nComplete an investigation into thunderstorm initiation using Doppler radar data and a mesoscale\nmodel.\nCOOPERATIVE INSTITUTE FOR LIMNOLOGY AND ECOSYSTEMS\nRESEARCH\nAnn Arbor, Michigan\n(313) 764-2426\nRussell A. Moll, Director\nThe Cooperative Institute for Limnology and Ecosystems Research (CILER) was established in 1989 as\njoint endeavor between the University of Michigan, Michigan State University, and NOAA's Great Lakes\nEnvironmental Research Laboratory (GLERL) in Ann Arbor, Michigan. The CILER administration, which\nis a located at the University of Michigan, promotes collaborative research between GLERL and scientists\nfrom throughout the Great Lakes Basin.\nCILER is the only joint institute with direct responsibilities for research in fresh water. However, CILER\nresearch activities are not limited to the limnetic environment; CILER also supports studies in estuarine and\ncoastal marine environments. The research foci for CILER fall into three areas: climate and global change,\ncoastal and nearshore processes, and large-lake ecosystem structure and function.\nCurrently, CILER has more than 70 Fellows who are affiliated with research institutions throughout the\nGreat Lakes Basin. The Council of Fellows, which is a subset of the total body of Fellows, provides the\nprimary intellectual guidance to CILER. The Council comprises individuals from GLERL, the University\nof Michigan, Michigan State University, the University of Minnesota, the University of Wisconsin, Purdue\nUniversity, The Ohio State University, and the State University of New York.\nCLIMATE AND GLOBAL CHANGE\nResearch supported by CILER in FY 92 and planned for FY 93 in the area of climate and global change\nfalls under the heading of regional Great Lakes mesoscale climate models. These models are powerful\ndiagnostic and predictive tools for investigating specific aspects of the interaction of climate forcing functions\nand the Great Lakes. Large lakes, such as those of the Laurentian Great Lakes of North America, have a\nsufficient mass of water to affect the local climate, and the lakes are in turn affected by overall climate change.\nDeciphering the interrelationships between large lakes and climate has best been accomplished to date by a\nmodeling approach.\n188","Joint Institutes-CILER\nAccomplishments FY 92\nGreat Lakes Forecasting System\nA primary goal of this project is to implement and test the forecasting system for real-time prediction of\nthe physical status of each of the Great Lakes. This system, which has been under development for several\nyears, is a part of a larger project in cooperation with GLERL to implement and test the Great Lakes\nForecasting System (GLFS) for real-time prediction of the physical status of each of the Great Lakes. A\nprototype system, the Lake Erie Information Forecasting System (LEIFS), advanced from a preliminary\nstart-up mode to the second stage at the beginning of FY 92. This second stage consisted of linking the\nvarious models of Lake Erie to yield nowcasts and forecasts of currents, water temperature, waves, and related\nphysical data. From its conception, the system was designed to provide information to the interested and\ninformed public as well as the scientific community. The projected uses of the system include Great Lakes\nhazard forecasting, enhancement of commercial and recreational activity on Lake Erie, an information base\nfor scenario testing and risk assessment, and resource preservation activities. The primary accomplishment\nfor FY 92 was taking forecasts that were only available in the laboratory and making them more generally\navailable to the public. This activity included improving in the nowcasts and forecasts and developing initial\nplans to implement a functional distribution system. The accomplishments from FY 92 research provide a\nfoundation on which to develop a Great Lakes mesoscale climate model.\nPlans FY 93\nGreat Lakes Forecasting System\nThe LEIFS project. is concluding the second stage with the controlled expansion of administrative and\nscientific activities, which will set the stage for moving into the next stage in FY 93. The goals for FY 93\ninclude completing LEIFS for nowcasting and forecasting throughout Ohio, evaluating the nowcast predic-\ntions for a minimum of one complete year of data, beginning the process of completing the lakewide\nestablishment of the distribution network, and beginning to move the LEIFS concept to other lakes and\nestablish the nowcast capability with product distribution through a test network.\nCoastal Wind Forecasts for the Great Lakes\nIn coastal areas, marine surface wind is the primary factor responsible for property damage and loss of\nhuman life during adverse weather conditions. There is a decided need to provide timely warnings of\nimpending adverse natural conditions to coastal communities so-that precautions can be taken to mitigate the\ndamages. In addressing marine surface wind prediction, the primary objectives for FY 93 are to test, evaluate,\nand\nmake refinements to marine boundary layer physics in the mesoscale models for wind predictions over\nthe Great Lakes. The focus will be on testing model performance over the coastal oceans and Great Lakes\nregions, looking for necessary changes in the grid representation of the coast line geometry and topography,\nand modifying the boundary layer physics to improve performance. Also, improved coastal wind analyses\ntechniques will be developed using the better coverage of wind measurements provided by the deployment\nof future satellites, aircraft winds, and the National Weather Service's Next Generation Doppler Radar\nnetwork.\n189","Coupled Hydrosphere-Atmosphere Research Model\nA greater understanding of coupled hydrosphere-atmosphere processes is important for many reasons:\nmaking short-term predictions of local land-lake hydrology, local meteorology, and related processes; tracing\nthe dispersion of pollutants in the air and in water bodies; and estimating potential impacts of climate or\nsurface change on a wide range of environmentally sensitive areas. Plans for FY 93 for the coupled\nhydrosphere-atmosphere research model project include combining research efforts from GLERL's simula-\ntions of the Laurentian Great Lakes water supplies through runoff and evaporation models with the Air\nResources Laboratory's (ARL) atmospheric models relating to the dispersion and deposition of airborne\npollutants. The objective is to couple these models into an interactive model that would offer more\nunderstanding of the dynamics between hydrologic and meteorologic processes. The final model will have\nready application to problems involving prediction of lake conditions, improved forecasting of lake-effect\nmeteorological phenomena, projection of areal water balances and hydrology, and examination of past and\nfuture climatic factors.\nTwo-Dimensional Great Lakes Heat Flux and Storage Model\nAn objective of the two-dimensional Great Lakes heat flux and storage research for FY 93 will be to\ninvestigate the possible effects of changing climate conditions by understanding lake surface energy flux and\ndeveloping a lake surface temperature model for each of the five Great Lakes. Lake evaporation from the\nGreat Lakes is of the same order of magnitude as precipitation and runoff to the lakes. Evaporation\ndetermines, to a large degree, the net water supply and lake levels. Knowledge of the energy flux at the water\nsurface is very important for quantitative water management. This knowledge is also important for qualitative\nwater management, because many biological processes, such as growth rates, depend on water temperature.\nThis project will go beyond the one-dimensional studies of the past where temporal variances of energy fluxes\nwere addressed, but not spatial patterns. The energy flux at the water surface of the Great Lakes will be\nmodeled with a high spatial resolution. The model will be based on well-calibrated and tested one-\ndimensional models developed at GLERL and on a two-dimensional energy flux model developed at the\nUniversity of Freiberg, Germany. The model will be driven by Advanced Very High Resolution Radiometer\n(AVHRR) satellite data and by meteorological measurements.\nCOASTAL AND NEARSHORE PROCESSES\nThe program of study in coastal and nearshore processes supported by CILER falls into three related topics:\nshoreline responses to forcing functions, wetland/estuary structure and function, and coastal exchange\nprocesses. In FY 92, activities were supported in the area of coastal exchange processes. These studies\nembraced a variety of aquatic environments including freshwater nearshore in the Laurentian Great Lakes\nand coastal marine in both the Gulf of Mexico and South Atlantic Bight. In all three environments the primary\nfocus of the studies has been the movement of critical materials from the shore into the adjacent water bodies\nand the consequences of that redistribution of materials.\n190","Joint Institutes-CILER\nAccomplishments FY 92\nNutrient-Enhanced Coastal Ocean Productivity\nA major project under coastal exchange processes was a study of the outfall of the Mississippi River in\nthe northern Gulf of Mexico. This research is a component of the NOAA Nutrient-Enhanced Coastal Ocean\nProductivity (NECOP) program. The fisheries in the Gulf of Mexico off the Louisiana coast are the richest\nand largest in the United States. This highly productive system is supported by abundant nutrient inputs from\nthe numerous freshwater tributaries. The plume associated with the Mississippi River outfall is the dominant\nsource of those nutrients. However, excessive nutrient enrichment from the Mississippi River outfall induces\nhypoxia under the edge of the plume during part of the year. The research objectives for FY 92 of this project\nincluded characterization of photoautotrophic community dynamics in relation to optical conditions, nutrient\ninputs, aspects of the physical/chemical environment, and development of conceptual and predictive models\nthat describe the production and fate of fixed carbon as a function of these same variables. The Mississippi\nRiver plume and adjacent shelf waters, which are representative areas subject to direct and indirect impact\nof riverine inputs, were sampled using two strategies. The first involved quantification of primary production,\nbio-optical, and hydrographic parameters in the mixed layer in conjunction with synoptic mapping activities.\nThe second consisted of detailed characterization of photoautotrophic production and growth. Sampling was\nconducted over a representative range of seasonal conditions, encompassing both high and low river flow\nperiods and temperature ranges.\nCILER-supported investigators also evaluated heterotrophic microbial processes in the Gulf of Mexico.\nThe warm water temperatures in particular appear to support high rates of bacterial metabolism, making these\nmicroorganisms an important component of the nearshore Gulf of Mexico food web. However, the actual\nrates of bacterial metabolism and the exact source of nutrients for the bacteria remain unknown. The\nresearchers hypothesized that riverine dissolved organic carbon (DOC) and dissolved organic nitrogen (DON)\nsupply a significant proportion of total heterotrophic and autotrophic nutrients for growth in the Mississippi\nRiver plume system. The importance of dissolved organic matter (DOM) to microbial growth rates in the\nMississippi River plume was evaluated by characterizing the chemical and isotopic composition of DOC and\nDON in the river outflow and offshore stations, and by examining the biological reactivity of the DOC and\nDON.\nVernal Thermal Fronts in the Great Lakes\nA second research project on coastal exchange processes involves the physical, chemical, and biological\nprocesses surrounding vernal thermal fronts in Lake Michigan. This springtime front is a fundamental feature\nof the warming of all large lakes of the world in temperate climates and appears to play a crucial role in the\ntransition from fully mixed midwinter conditions to thermally stratified summer conditions. Six investigators\nconducted three multivessel research cruises to eastern Lake Michigan in FY 92 to study the formation and\nprogression of the thermal front. The governing mechanisms of this frontogenesis were studied, and yielded\na better map of the circulation at the front and strengthened the theoretical formulation for the two-\ndimensional, time-dependent thermal front circulation.\n191","Plans FY 93\nNutrient-Enhanced Coastal Ocean Productivity\nAs part of the effort to quantify the impact of the Mississippi River's discharge and sediment loads on the\ncoastal ecosystem of the Gulf of Mexico, for FY 93 this project will focus on community respiration involving\nphotosynthesis and respiratory metabolism of organic matter as well as gas exchange with the atmosphere\nas the primary determinants of the vertical distribution of dissolved oxygen in the ocean. The area least\nstudied to date has been measurements of respiration in the ocean because of a lack of precision in\ndetermining the small changes in the concentration of dissolved oxygen or total CO2 in samples over short\ntime periods. The researchers will use a titration and ultrafiltration to isolate DOM from each study region\nfor detailed chemical and isotopic characterization.\nVernal Thermal Fronts in the Great Lakes\nLong-term ecological monitoring of an open water station in Lake Michigan has been conducted by the\nGLERL since the mid-1970s in a variety of capacities. In 1983, the monitoring project was expanded to\ninclude analysis for nutrients, chlorophyll, carbon, bacteria, phytoplankton, and zooplankton at approximately\nbiweekly intervals during ice-free conditions. A more detailed sampling program in FY 93 will examine\necological changes associated with development and migration of vernal thermal fronts. The overall\nobjectives of this project include (a) determination of seasonal and long-term trends to enhance understanding\nof the ecosystem; (b) detection of water quality and ecological changes due to perturbations by climate change,\nnutrient pollution, toxic contamination, nonindigenous species introduction, and fish management; and\n(c) expansion of a data base describing water quality and ecological conditions of open-water Lake Michigan.\nThermal front studies planned for FY 93 include 8 weeks of intensive field studies in April and May in\neastern Lake Michigan. Using two ships and moored instruments, scientists will investigate subsurface and\nnear-surface currents in the vicinity of the thermal front; identify and characterize the thermal fields, chemical\nfields, and plankton distributions in three dimensions; and measure near-front plankton productivity. Field\nsampling will be supported by satellite remote sensing of Lake Michigan surface water temperatures.\nSouth Atlantic Bight Recruitment Experiment\nLarval survival and juvenile development are critical stages in the life history of any fish. In the case of\ntransgressive fish species, these stages are separated temporally and spatially. Beginning in FY 93, the South\nAtlantic Bight Recruitment Experiment (SABRE) seeks to understand how these developmental stages\nbecome distinct in time and space and to subsequently identify the processes and interactions that can lead\nto successful recruitment. The research will focus on the identification and quantitative characterization of\nphysical mechanisms that are most likely to be responsible for the initial oceanic-to-estuarine spatial transition\nseparating larval and adult life stages. In particular, the study will focus on critical aspects of the near-surface\n(upper 10 m) physical variability in shelf waters, especially those associated with the cross-shelf component\nof the velocity field. The field measurements will promote process-oriented studies of physical-biological\ninteractions pertinent to SABRE goals: for example, accurate estimation of near-surface, cross-shelf\nadvection and transport of egg masses or larvae. The analyses will take into account both historical data and\nnew field data.\n192","Joint Institutes-CILER\nCoastWatch\nAs part of the overall NOAA program of CoastWatch to develop and deliver environmental data and\nproducts to support environmental science and decision-making, this project will support Coast Watch\noperations at the Great Lakes Coast Watch Regional Site at GLERL. Primary activities in FY 93 will include\nthe daily operation and maintenance of the NOAA Ocean Communications Network node at GLERL and the\nreceipt, archival, and dissemination of Coast Watch-managed data.\nHydrodynamic Research in Lake Champlain\nUnderstanding complex whole-lake physical dynamics requires long-term observations of the temporal\nand spatial responses of lakes. Circulation studies and modeling efforts on Lake Champlain require\ninformation on the exchange rates between the central lake and associated shallow basins and the mass fluxes\ninto and out of each basin. As part of an overall effort to develop a whole-lake long-term monitoring system,\nin FY 93 this project will support two independent yet linked hydrodynamic study programs. The first will\nexpand an array of instruments on an existing taut-wire mooring to measure spatial and temporal current\npatterns. The enhancement of the mooring will permit the investigation of waves within the central basin of\nLake Champlain. The second will be a pilot project aimed at demonstrating the feasibility of deploying\ninstruments in the passageways between the subbasins and the central lake with current, temperature, and\nwater level recording sensors. Included in this project is the development of an automatic downlinking\nPassage Exchange Network (PEN). The PEN stations will be designed to provide information needed to\nsolve basin exchange problems.\nLARGE-LAKE ECOSYSTEM STRUCTURE AND FUNCTION\nCILER research in large-lake ecosystem structure and function has been divided into five topics:\ncomparative limnology, limnological ecosystem structure and function, ecosystem stresses from toxic\nsubstances, impacts of nonindigenous species invasions, and fisheries recruitment dynamics. In FY 92,\nCILER studies were conducted in three topics: limnological ecosystem evolution, ecosystem stresses from\ntoxic substances, and impacts of nonindigenous species invasions. The studies of impacts from nonindi-\ngenous species invasions include a particularly large overall effort in Saginaw Bay. That project is\ninvestigating the effects of the zebra mussel invasion by evaluating the Saginaw Bay ecosystem both before\nand after zebra mussel infestation.\nAccomplishments FY 92\nCarbon and Nitrogen Dynamics in Pelagic/Benthic Energy Transfer\nin the Laurentian Great Lakes\nRecent studies suggest that annual energy requirements of the benthic macrofauna community in Lake\nMichigan may be met in part by direct assimilation of much of the spring diatom bloom biomass. If this is\ntrue, then benthic amphipods must also play a significant role in organic matter remineralization in surficial\nsediments, assuming about one-half of their assimilated energy is lost through respiration. During FY 92,\nthe direct transfer of energy from spring diatoms to Diporeia sp., an abundant benthic amphipod, was studied\n193","by monitoring the decomposition kinetics of 14C-labeled diatoms (Melosira italica) in microcosms with\nanimals and surficial sediments. Production rates of 44CO2, cycling of dissolved organic carbon (DOC),\ndecomposition rates of added labeled substrate (POC), and incorporation of radioactivity into amphipod\nbiomass were measured. A budget was constructed for benthic carbon cycling with terms for input,\nassimilation, remineralization, and burial. The objectives for this study included (a) to determine the\npathways and efficiency of organic carbon and energy transfer between the spring diatom bloom and Diporeia\nsp., (b) to compare measured and modeled fluxes of organic and inorganic nitrogen compounds across the\nsediment/water interface to address the following hypothesis, and (c) investigate the use of stable isotopes\nas possible tracers of carbon flow in both surficial and sediment microbial ecosystems.\nInter- and Intraspecific Variation in Food Quality: Mechanisms and Benefits of Selective\nHerbivory by Calanoid Copepods\nIn marine and freshwater pelagic environments, planktonic organisms account for nearly all primary\nproduction and the majority of primary consumption. As a major component of the primary consumers,\ncalanoid copepods comprise a substantial portion of the energy available in aquatic food chains. The\ncopepods thus have the potential to operate as major regulators of energy transfer to higher trophic levels as\ntheir survival, growth rate, and reproductive activity respond to changing environmental conditions. Because\nthe copepods receive the majority of their food energy from phytoplankton, calanoid populations are most\nsusceptible to changes in the quality of available phytoplankton. The underlying hypothesis of this study is\nthat the quality of available algal food affects the quality and quantity of herbivorous zooplankton. This study\nexplored the interaction between algal quality (i.e., chemical composition) and subsequent food detection\ncapabilities, taste preference, and productivity of calanoid copepods. Research focused on the calanoid\ncopepod Diatomus sicilis, a hypolimnetic species common in the Great Lakes. This species represents a\nmajor food source for young whitefish, a commercially valuable freshwater fish as well as popular sport fish\nin the Great Lakes.\nStudy of the Lower Saginaw River\nThe Saginaw Bay watershed is one of the most important resources in Michigan. The watershed supports\noutstanding recreational and commercial fisheries, provides excellent habitat for wildlife, offers good\nrecreational opportunities, includes highly productive farmland, and supports an impressive industrial\ninfrastructure. Despite the value of this natural resource, Saginaw Bay and some of the rivers of the watershed\nhave received an excessive amount of pollution, particularly in the form of hydrophobic organic compounds\nand metals. Recent mitigative measures have resulted in an improvement to the waters of Saginaw River\nand Bay, but many of the sediments remain highly contaminated. The purpose of this project was to provide\nfurther information on the lower Saginaw River and adjacent Saginaw Bay on the status of metal and\npolychlorinated biphenyls (PCBs) contamination in water, attached to suspended particles and in selected\nportions of the aquatic biota. This study addressed several research objectives, including a better under-\nstanding of the temporal and spatial sources of loads of metals and PCBs to the river and bay. Beginning\nin\nFY 91, sampling was conducted over a 1-year period. CILER researchers participating in this study worked\nin conjunction with other EPA-sponsored investigators. The researchers sought to determine, whether, during\nlarge storms, the contaminants found in the sediments of the river were mobilized into the water column and\nfrom there into the aquatic biota. Those same data also will serve as a primary source of information for a\nmass-balance model and near-field and far-field dispersion models. The results of this study and the modeling\neffort taken together will assist in developing a plan for future management of the Saginaw Bay watershed.\n194","Joint Institutes-CILER\nAssimilation of Selected PAHs and PCBs\nPolyaromatic hydrocarbons (PAHs) and PCBs enter the aquatic environment from a variety of sources,\nincluding the incomplete combustion of petroleum products. These compounds, which are carcinogenic, are\nneutrally lipophilic and tend to accumulate in sediment. An unresolved question is whether or to what extent\nthe sediment acts as a sink, preventing these compounds from moving back into the food chain. A general\nlack of data surrounding the processes by which invertebrates assimilate sediment-sorbed xenobiotics was\nthe primary rationale to better define the role of ingestion in the process of bioaccumulation. The relative\nimportance of interstitial water versus diet as a contamination source of sediment-sorbed xenobiotics to\naquatic biota remains under debate. Most work has shown that interstitial water is the main contamination\nsource. However, ingestion of contaminated sediments may also contribute significantly to bioaccumulation.\nThis study investigated the relative importance of ingestion to bioaccumulation by measuring assimilation\nefficiencies for invertebrates exposed to sediment-sorbed xenobiotics. In addition, a standard method for\ndetermining assimilation efficiencies was investigated SO that comparisons could be made among species and\nchemicals.\nAssessment of the Lower Food Web of Saginaw Bay - Impact of the Zebra Mussel\nThis project is an expansion of an effort to determine the ecological impacts of the zebra mussel on the\nlower food web of Saginaw Bay. The research effort was initiated in FY 90 to document conditions before\nthe infestation of Saginaw Bay by zebra mussels. Zebra mussels were found for the first time in Saginaw\nBay in the fall of 1990, and an expanded program of study was conducted in FY 91 and FY 92. With\ninvestigators from GLERL, the University of Michigan, Michigan State University, Saginaw Valley State\nUniversity, The Ohio State University, Bowling Green University, University of Minnesota, and Kent State\nUniversity, this program included measurement of all the relevant variables needed to document changes to\nthe lower food web. Sampling by the team of scientists in Saginaw Bay included the plankton, benthic algae,\nbenthos, wetlands, fish, and sediments. The primary rationale of this research is to decipher the large-scale\nchanges to Saginaw Bay as the zebra mussel population reaches infestation levels. Timing to date on this\nproject has been excellent in that zebra mussels were found in small numbers in Saginaw Bay in the early\nspring of 1991 and in abundance by the fall of 1991. The zebra mussel population reached infestation levels\nduring the summer of 1992. Laboratory experiments investigated the feeding behavior and physiological\nenergetics of zebra mussels.\nThe Impact of Zebra Mussels on the Biology of Benthic Algae\nSaginaw Bay, Lake Huron, which is in many ways is similar to western Lake Erie, was not extensively\ncolonized by zebra mussels until late summer 1991. In 1991 a study was initiated to examine the biology of\nthe benthic algal community in a detailed manner before the infestation by zebra mussels and associated\nchanges in water clarity. Research that continued into FY 92 provided data on the changes in the structure\nand function of benthic algal communities of Saginaw Bay following zebra mussel infestation. The study\narea, between North and South Charity Islands, is representative of prime zebra mussel growth zones with a\ngood range of shallow depths and rocky bottoms. The accomplishments from FY 92 show that the well-\nestablished benthic algal communities growing on the hard bottom substrates of Saginaw Bay will be\nsignificantly affected by the increasing densities of zebra mussels. The invading organism has had a major\nimpact on water clarity and brings much more light to the benthic algal communities. The zebra mussels\nhave also changed the surface characteristic of the bottom by colonizing most of the hard substrates. Zebra\n195","mussel infestation also appears to have affected nutrient concentrations in Saginaw Bay, which in turn may\nalter benthic algae productivity.\nMacrophyte Abundance and Distribution in Saginaw Bay Relative to the Abundance of Dreissena\npolymorpha\nOn the basis of observations in Lake Erie, the zebra mussel has the potential through filter feeding to reduce\nfish food resources, greatly reduce plankton biomass, improve water clarity, increase light penetration, and\nincrease submersed macrophyte abundance on shallow littoral sediments. Determining whether expansion\nof these macrophyte beds and associated food resources is a benefit or detriment to the fishery is an objective\nof this project. In FY 91, hard substrates were poorly colonized or not colonized by almost all forms of\naquatic flora and fauna because of low underwater light intensity and high turbidity. A 5-year study was\ninitiated in FY 91 that included measurement of turbidity, underwater light, and macrophyte distribution.\nRelative quantities of invertebrate food items for early life stages of fish were measured in the macrophyte\nbeds in FY 92 to test the prediction that increased macrophyte production in the inner bay will increase the\nabundance of littoral food resources for early life stages of fish and increase the capacity of the nearshore\nzone to support fish growth.\nPseudofeces Production by Zebra Mussels: Selective Rejection of Food and Impact on\nSaginaw Bay Ecosystem\nZebra mussels may have two major impacts on particle dynamics in eutrophic bays of the Great Lakes.\nThe research objectives of this study include the analysis of the impact of the zebra mussels on particle\ndynamics in Saginaw Bay: size-specific rejection of particles in pseudofeces; the role of chemoreception in\nrejection; the effects of large amounts of pseudofeces on filtration by members of a druze (a clump of zebra\nmussels); and the effects of copious amounts of pseudofeces on fitness of mussels and other benthos. The\nresults of the research showed that zebra mussels produced pseudofeces that were 20 to 100 times larger than\ntheir planktonic food. In creating these large pseudofeces, the zebra mussels benefited by eliminating\nunnecessary or low-quality foods and by keeping a storehouse of food in their druze (small local cluster of\nmussels). Although the costs of this behavior to the zebra mussel might be high because of the production\nof mucus, there might be a degree of efficiency through the production of very large pseudofeces.\nThe Effects of the Zebra Mussel on the Fate of Organic Material Produced in Saginaw Bay\nIn the process of filtering particles and excreting dissolved and particulate organic residues back to the\nwater column and sediments, the zebra mussel may have a profound effect on the microbial food web and\nthe biogeochemistry of major nutritional elements such as carbon and nitrogen. A primary objective of this\nstudy was to test the hypothesis that zebra mussels modify the flow of the photosynthetically fixed energy\nfrom anabolic (biomass production) fate to catabolic (respiratory loss) processes in Saginaw Bay. Mesocosm\nexperiments were performed in FY 92 to determine bacterial morphology and dynamics in the mesocosm in\nthe presence and absence of zebra mussels; to determine the composition and dynamics of dissolved organic\ncarbon and nitrogen, and particulate organic material in the respective mesocosms; and to determine release\nrates of DOC, DON, and ammonium by zebra mussels.\n196","Joint Institutes-CILER\nPlans FY 93\nEarly Diagenesis of Organic Matter in Sediments of the Great Lakes\nOrganic matter, a small but important fraction of lake sediments, represents the residue from previous\nliving biota and therefore provides information about paleolimnologic changes. Portions of organic matter\nsediment constitute the food of benthic infauna, and the availability of these portions is important to lacustrine\nfood chains. Organic matter sediment includes both naturally synthesized compounds and material produced\nby industrialized society. The rates of cycling of both types of organic matter components are important to\nlake ecosystems. The biological and chemical processes that alter and degrade the organic matter components\nare termed \"early diagenesis.\" They act together to erase the paleolimnologic record, modify the nutritional\nvalue, and recycle the natural and pollutant components contained in organic sedimentary matter. As the\ninitial stage of a multiyear investigation, in FY 93 this study will examine the early diagenesis rates and effects\nof organic matter in sediments in Lakes Erie and Ontario as models of processes in smaller lakes and in\noceans.\nLevels and Deposition of Atmospheric Mercury in the Lake Champlain Basin\nThe overall objective of this project is to assess the magnitude and seasonal variation of atmospheric\nmercury in the Lake Champlain Basin. Mercury contamination of aquatic organisms in eastern North\nAmerica has led to costly bans on consumption of fish taken from some lakes in this region. Further, mercury\nbioaccumulates in animal tissues cause neurological disorders and, in acute cases, renal failure. Mercury\npoisoning not only affects human health, but that of the ecosystem as a whole. As part of the effort to\nunderstand the cycle of mercury in aquatic and terrestrial ecosystems, the importance of the atmospheric\npathway to these cycles has become well recognized. For this project, the University of Michigan Air Quality\nLaboratory in cooperation with the Vermont Monitoring Cooperative and the Lake Champlain Research\nConsortium will conduct state-of-the-art atmospheric mercury measurements in FY 93. The results of this\nproject will assist in the implementation of a stringent quality assurance plan.\nAssessment of the Lower Food Web of Saginaw Bay - Impact of Zebra Mussel\nThe proposed research is a continuation into FY 93 of the effort to determine the ecological impacts of the\nzebra mussel on the lower food web of Saginaw Bay. Research was initiated in the spring of 1990 to document\nconditions before the establishment of the zebra mussel. Activities were expanded in 1991 by increasing the\nnumber of sampling periods, the number of samples, and the number of parameters measured. Also, the zebra\nmussel population in Saginaw Bay increased dramatically in late 1991, and studies were initiated to document\nsettling rates and abundances. Research during FY 93 will include analysis and organization of all previously\ncollected data as well as further field sampling and data collection.\n197","COOPERATIVE INSTITUTE FOR MARINE AND\nATMOSPHERIC STUDIES\nMiami, Florida\n(305) 361-4169\nJoseph M. Prospero, Director\nThe Cooperative Institute for Marine and Atmospheric Studies (CIMAS) is an association between the\nNational Oceanographic and Atmospheric Administration (NOAA) and the University of Miami's Rosenstiel\nSchool of Marine and Atmospheric Science (RSMAS). The primary purpose of CIMAS is to facilitate and\nstimulate cooperative research between these two institutions. There are two research themes in CIMAS:\nClimate Variability, and Fisheries Ecology and Ecosystem Dynamics.\nCLIMATE VARIABILITY\nThese studies focus on those aspects of ocean dynamics that are important for understanding climate\nmechanisms and for predicting climate change. FY 92 activities fell mainly within the Atlantic Climate\nChange Program (ACCP) and to a lesser degree the Equatorial Pacific Ocean Climate Studies (EPOCS). In\nFY 92 new efforts were initiated under the NOAA Climate and Global Change Program (CGCP).\nThe oceanographic component in CIMAS is concentrated in the ACCP. The ACCP studies focus on the\nbasic processes and the variability associated with export of cold deep waters from the North Atlantic to the\nrest of the world ocean system and on the associated warm water transport from the tropics into the northern\ntemperate latitudes. It is important to develop an extended time series in the Florida-Bahamas section of the\nAtlantic western boundary regime because the overturning process, known as the Atlantic Conveyor Belt, is\ndynamically concentrated in this region. Complementing the ACCP activities, we initiated a cooperative effort\nwith the National Environmental, Satellite, Data, and Information Service (NESDIS) and the National\nAeronautics and Space Administration (NASA) to analyze and improve sea-surface temperature (SST)\nproducts.\nSome of the activities in CIMAS that focus on atmospheric processes relating to climate are associated\nwith the Radiatively Important Trace Species (RITS) program, which emphasizes the greenhouse gases. Many\nof the newer programs are concerned with the role of aerosols in climate. Some continuing efforts in this area\nare associated with the Pacific Sulfur/Stratus Investigation (PSI), while others are associated with the CGCP.\nTHERMOHALINE CIRCULATION AND MERIDIONAL HEAT FLUX IN\nTHE WESTERN SUBTROPICAL ATLANTIC\nAssessing variability in the interhemispheric heat exchange by the thermohaline circulation is a major\nproblem in the study of oceanic impacts on the global climate. Development of long-term records of oceanic\nmass and heat transports, essential for this purpose, was begun under the Subtropical Atlantic Climate Studies\n(STACS) program in a joint effort by AOML and CIMAS scientists; this work continues with combined\nsupport from ACCP and the World Ocean Circulation Experiment (WOCE) of the National Science\nFoundation (NSF).\nLong-term time series of volume and heat transports are recognized as essential for estimating the\nvariability of inter-hemispheric thermohaline circulation on seasonal and longer time scales. Earlier joint\n198","Joint Institutes-CIMAS\nefforts between RSMAS and AOML under the umbrella of the STACS program, to directly measure the\nvolume and heat transport components of the thermohaline circulation in the western subtropical Atlantic,\nare being extended with joint support from ACCP and WOCE.\nAccomplishments FY 92\nA moored current meter array was deployed east of Abaco, Bahamas, for a 1.5-year period beginning in\nJanuary 1992. This array will extend the existing 7.5-year time series of boundary current transports. This\nsite that is a prime candidate for long-term climate change observations. The arrays measure waves,\ntemperature and current speed and direction. Comparisons with flow fields in preceding years indicate that,\non average, the deep western boundary current (DWBC) was contained against the Bahamas slope but that\nthe interannual variability was weaker than in previous years. The mean meridional flows also show a\nwell-defined northward jet of warmer thermocline waters that hugs the Bahama slope. This jet is formed by\nthe combined influence of the northward-flowing Antilles Current and a clockwise Gulf Stream recirculation.\nLarge offshore-onshore meanders of the DWBC occurred on 100-day time scales with offshore displacements\nof about 80 km.\nEstimates of volume and heat transports from mooring data were compared with the Community Modeling\nEffort (CME) model. Preliminary results suggest that the structure of the western boundary currents observed\noff Abaco and the monthly mean seasonal transport variations are remarkably similar to those in the CME\nmodel. However, the CME model appears to underestimate the northward heat transport of the mean\nthermohaline circulation. Heat transport time series estimated from the moored array east of Abaco show\nlarge baroclinic heat flux variations on time scales of 1-2 months, which is typical for baroclinic eddies.\nConsidering their frequency of occurrence, these variations could introduce errors on the order of 20% in\nmean heat transport estimates. Such errors can only be controlled by direct observations of the currents.\nPlans FY 93\nWe will continue our investigation of the structure and variability of volume and heat transports associated\nwith western boundary currents and thermohaline circulations in the subtropical Atlantic. We will use data\nsets from moored current meters to derive transport time series that can be related to wind forcing over the\nAtlantic on annual and longer time scales. Numerical models predict a robust annual cycle that is forced by\nseasonal winds. Our objective is to see if this cycle can be resolved from longer time series data sets by\naveraging out the large-amplitude, 100-day period fluctuations. Initial results suggest that this should be\npossible. We will make a detailed analysis of the Abaco array data to assess the implications for heat transport.\nA major objective of our activities is to identify climate-forced fluctuations in hydrographic data records.\nThis is a difficult task because we expect that climate-related changes in mean meridional transports will be\nrelatively small and difficult to detect in the presence of local recirculating gyres and strong eddy effects.\nCIMAS and AOML investigators will continue to collaborate in efforts to integrate a wide range of regionally\nacquired hydrographic data that bear on the issue of climate-related trends with the objective of identifying\nclimate-driven variability in the presence of short-term changes driven by other factors.\n199","MOORED ARRAYS IN WESTERN TROPICAL ATLANTIC\nThe meridional exchange of water masses in the western tropical Atlantic is a critical component of the\nAtlantic climate system. We wish to characterize the dominant water mass exchange processes in the western\ntropical Atlantic and provide data for testing and evaluating the performance of numerical ocean models.\nAccomplishments FY 92\nWe essentially completed the analysis of data from a current meter array that was deployed from September\n1989 to September 1991. This program was part of a larger-scale, internationally coordinated observational\nprogram in the tropical Atlantic, Western Tropical Atlantic Experiment (WESTRAX). These observations\nare compared with the results of high resolution numerical ocean models that were obtained by several groups\nat other institutions. The annual mean meridional mass transport is clearly split into two components:\n(1) northward transport of surface and thermocline waters in the North Brazil Current, and (2) a deep\nsouthward transport in the western abyssal boundary layer that is carried by strong jets near 2000-m and\n4000-m depth.\nMesoscale variability throughout this region is dominated by fluctuations with periodicities near 40-60\ndays. These fluctuations are associated with instabilities in the North Brazil Current that cause eddies to\nperiodically break off from the Current and drift northward. As a result of this process, large volumes of the\ntropical surface water mass, which is largely of South Atlantic origin, are entrained into the subtropical\ncirculation domain. We have begun a study of the performance of several North Atlantic circulation models\nwith regard to this eddy exchange process. How accurately the models reproduce eddy exchange processes\nmay be a critical test of model performance in a climate context.\nPlans FY 93\nDuring the coming year, we will complete the analysis of the moored current meter records collected in\nthe western tropical Atlantic near 4°N during 1989-1991. Analysis will include the following:\nDocumentation of the seasonal transport cycle of the North Brazil Current, the flow patterns\nconnecting the western boundary flow to the interior Atlantic, and the properties and dynamics of\nthe energetic mesoscale eddy field in this region.\nFurther investigation of Atlantic Basin numerical models regarding the pathways and mechanisms\nof interhemispheric exchange in the Atlantic and of the dynamical processes controlling the\nmesoscale eddy field, based on model-data comparisons.\nSynthesis of the recent current meter data with earlier current meter observations near 8°N (1987-\n1989) and with other data sets available from the WESTRAX program. These will be used to describe\nthe large-scale, top-to-bottom circulation and seasonal variability in the tropical North Atlantic.\nTRANSPORT AND WATER MASS PROPERTIES IN WINDWARD\nISLANDS PASSAGES\nAtlantic climate dynamics are affected by the relative contributions of the Gulf Stream mass transport of\nsurface waters recirculating in the subtropical North Atlantic and those deriving from the tropical Atlantic.\n200","Joint Institutes-CIMAS\nThese transports can be studied most effectively in the island passages between the Atlantic and the Caribbean.\nTo this end we established a collaborative program between the United States and Barbados to conduct regular\nmeasurements of the transport and water mass characteristics in the major southern passages to the Caribbean.\nA Barbados Coast Guard vessel makes monthly patrols in this area. The ship has been equipped to collect\nstandard hydrographic measurements (conductivity, temperature, depth; CTD) and water samples, and to\nmake current velocity profile measurements using a downward-looking Acoustic Doppler Current Profiler\n(ADCP).\nAccomplishments FY 92\nThis effort has demonstrated that small foreign vessels can be equipped for regional oceanographic surveys\nat low cost. We set in motion plans for long-term operational monitoring with local support. Two cruises\nwere completed, and high-quality data sets (including profiles of velocity, temperature, salinity, and dissolved\noxygen content) were acquired at 14 stations in Grenada, St. Lucia, and St. Vincent Passages. On these cruises\nwe also tested and verified a new technique for measuring accurate absolute velocity profiles at discrete\nstations using an ADCP deployed over the side. The data showed strong seasonal differences in transport. In\nthe December 1991 data, subtropical Atlantic water was observed in all of the passages; in contrast, in May\n1992, waters with South Atlantic or equatorial origin were present both near the surface and within the deeper\npart of the thermocline.\nPlans FY 93\nEight additional cruises are planned during 1993. Initial scientific analysis will focus on the flow structures\nand transports in the passages and on the associated water mass variability, especially the relative contribu-\ntions of North and South Atlantic sources to waters flowing into the Caribbean.\nCHLOROFLUOROCARBONS AS TRACERS OF\nDEEP WATER FLOW PATTERNS\nChlorofluorocarbons (CFC) are used as tracers of water that has recently sunk from the surface, where it\nhad equilibrated with the atmosphere (ventilation), to depths where it is isolated from exchange with air. The\nCFC tracer is used to follow its subsequent spreading by the abyssal currents. Because CFC atmospheric\nconcentrations are changing rapidly, the ratio of specific CFC compounds can be used as a time marker for\nwater mass properties. When coupled with hydrographic data, CFC data help define the climatically important\ndeep water renewal rates.\nAccomplishments FY 92\nThe CFC observations made over the past several years in the subtropical western boundary current off\nAbaco and the Bahamas show that recently ventilated Northern Hemisphere water moves toward the Equator\nin the DWBC in two distinct lobes or cores. In contrast to earlier observations off Abaco in the Bahamas,\nwhere subtropical circulation appears dominant, the tracer data suggest that only about 20% of the DWBC\n201","transport closer to the Equator appears to consist of recirculating waters. The properties of these waters\nsuggest an origin in the Southern Hemisphere.\nWater with relatively high CFC concentrations reaches into the interior of the Atlantic basin to about 20°N\nas well as into the tropics. This pattern indicates that the effects of forcing in the high latitudes are rapidly\nmanifested in transport processes occurring not only along the western boundary of the North Atlantic but\nalso in the interior. The initial analysis of the CFC data collected in June-July 1991 near the Blake Bahama\nOuter Ridge indicates that topography controls the path of ventilated bottom water. The ventilation connec-\ntions between the subtropical western North Atlantic and the western boundary region were studied by\nmeasuring CFCs on a multi-investigator cruise on the R/V Trident in August 1992.\nPlans FY 93\nWe will complete the final calibration and preliminary analysis of the data from the August 1992 Trident\ncruise. We will continue interpretation work with other ACCP investigators, focusing on interior basin\nventilation in general. The initial task is the completion of a paper on the data from the Blake Bahama Outer\nRidge.\nATLANTIC SST ANOMALY DYNAMICS\nThe dynamics of the formation of SST anomalies (SSTA) is an important element of climate-related air-sea\ninteraction processes. The Comprehensive Ocean-Atmosphere Data Set (COADS), derived from shipboard\nobservations, and the satellite-derived (infrared) Multi-Channel Sea Surface Temperature (MCSST) product\nare used to identify the probable role of transient surface currents in SSTA generation.\nAccomplishments FY 1992\nWe studied SSTA variability in the Atlantic between 20°S and 60°N using COADS fields and we made a\npreliminary comparison between SSTA fields derived from the COADS and from the satellite-derived\nMCSST product. This work confirms that COADS fields can be used to provide a partial accounting of the\nthermal balance associated with SSTA variability at interannual periods as a function of location, season, and\nfrequency.\nHeat advection due to geostrophic and Ekman transport appears to significantly influence SSTA variability\nat periods of several decades in the Atlantic north of about 30° N. This effect arises from a nonlinear interaction;\nanomalous geostrophic and Ekman transports are significantly correlated with anomalous SST gradient at\nperiods of one to several years (only at periods of several years for geostrophic transport).\nForcing terms can be estimated from COADS fields, but these cannot account directly for the large-scale\nSSTA change in the Atlantic that occurred from the early 1950s through the late 1970s, that is, cooling north\nof the Equator and warming to the south. For example, all these terms acted to warm SST off of Newfound-\nland; in contrast, the largest cooling was observed in this region.\n202","Joint Institutes-CIMAS\nPlans FY 93\nGenerate Atlantic Ocean SSTA maps from the satellite-derived MCSST product using an objective\nanalysis package and then analyze and compare the properties of SSTA variability present in both\nthe MCSST and COADS fields.\nAnalyze the dynamics of SSTA variability using the MCSST SSTA fields and surface flux fields from\nthe European Centre for Medium-Range Weather Forecasting (ECMWF) and contrast the results of\nthis analysis with results obtained using COADS fields alone to assess the influence of errors and\nbiases present in the different data sets.\nAnalyze the dynamics of SSTA variability in the Atlantic using runs of the Miami isopycnic-\ncoordinate numerical model forced by both COADS and ECMWF surface flux fields. Compare and\ncontrast these results to results obtained using data alone. Use model fields to relate SSTA variability\nto anomalous variability in wind-driven and thermohaline circulation in the ocean.\nAVHRR SEA SURFACE RETRIEVAL ALGORITHMS\nNESDIS and the RSMAS Remote Sensing Laboratory initiated a program to improve the sea surface\nretrieval algorithms used with the NOAA Advanced Very High Resolution Radiometer (AVHRR) satellite\nsensor. Program activities include improving the infrastructure at NOAA to manipulate and analyze the large\nvolumes of global SST satellite and in situ data as well as developing test data sets to test the behavior of all\nfacets of SST computation. A key part of this involves participation in the NOAA/NASA AVHRR Pathfinder\ncalibration group.\nAccomplishments FY 92\nA calibration data base was developed for all AVHRR sensors using thermal vacuum test measurements.\nThe thermal vacuum data base was provided to the NOAA/NASA AVHRR Pathfinder calibration working\ngroup. An analysis of thermal vacuum measurements led to the development of a new algorithm to correct\nnonlinear behavior for the infrared (IR) AVHRR channels. Development of an in situ and AVHRR match-up\ndata base will be initiated for the development and testing of AVHRR SST algorithms and data rejection\ntechniques.\nPlans FY 93\nContinue to work with the AVHRR Pathfinder calibration panel to determine an \"official\" AVHRR\ncalibration algorithm.\nInstall and integrate the new NESDIS satellite data analysis system.\nTransfer initial Pathfinder SST algorithms and reference data sets to NESDIS for collaborative\nanalysis.\nInitiate studies to improve SST algorithms in areas affected by aerosols. This activity will be a\ncollaborative effort between NESDIS and RSMAS investigators. A postdoctoral position will be\nfilled at RSMAS to assist in this effort.\n203","MARINE SULFUR SOURCES, AEROSOLS, AND CLIMATE\nAerosols can affect climate in two ways: directly, through the scatter and absorption of radiation, and\nindirectly, by modifying cloud properties and hence their albedo. Of particular interest are the sources,\nproperties, and fate of sulfate aerosols, and the dominant species in the marine aerosols. Over the ocean, the\ntwo important sources of sulfate aerosols are anthropogenic sources and organic sulfur compounds (of which\ndimethylsulfide, DMS, is most important) derived from biogenic activity in the ocean. CIMAS activities\nfocus on (1) the biological processes in the ocean that produce DMS and related compounds, (2) the\nphysical/chemical processes that control the emission of these gases to the atmosphere and the complex\nchemistry that can result in the formation of sulfate aerosols, and (3) the physical and chemical properties of\nthese aerosols and their impact on the radiative properties in the atmosphere.\nExamining oceanic sources of organic gases focuses on the biochemical processes in surface waters that\nrelate to the production of DMS (and related compounds) and organic halocarbons. DMS plays a central role\nin the atmospheric sulfur cycle over the oceans. One of the principal oxidation products of DMS is sulfate\naerosol, which in remote ocean regions is a major source of cloud condensation nuclei. Hence, processes that\naffect the emission of DMS from the oceans can have an impact on cloud properties and climate. Similarly,\norganic halocarbons emitted from the oceans can be important to atmospheric halocarbon chemistry and can\nserve as an important source in the global atmospheric budgets of these materials.\nThe high latitude North Atlantic is of interest to us because of the extremely high rate of primary\nproductivity in this region and the consequent production of high concentrations of DMS which is emitted\ninto the atmosphere where it is oxidized to form aerosols.\nThe effect of aerosol scatter and absorption on solar radiation can be measured by measuring the direct\nsolar beam intensity in narrow wavelength bands. These measurements of aerosol optical depth (AOD), when\ncoupled with the study of aerosol properties, can provide insights on natural and anthropogenic climate\nimpacts. AOD measurements were initiated under the CGCP in a cooperative effort with CMDL and NESDIS.\nThese data will be used to validate and improve the algorithms for retrieving aerosol data from current satellite\nsystems (such as AVHRR), and they can serve as the foundation for the development of algorithms for the\nnext generation of satellites such as Sea Wide Field Sensor (SeaWiFS) and Moderate Resolution Imaging\nSpectrometer (MODIS).\nAccomplishments FY 92\nOceanic Sources of Organic Gases\nOn a cruise to the equatorial Pacific on the R/V Vickers, we measured methyl halides to compare fluxes\nfrom productive (2°S) and oligotrophic (12°S) waters, and to calculate sea-air exchanges of these biogenic\ntrace gases. We also sampled for total organic particulate sulfur. These data will be used to constrain the\ncycling of trace sulfur gases in the upper water column as a function of depth and microbiological rate studies.\nObservations of Trace Sulfur Gases\nMeasurements of trace sulfur gases were made in the South Atlantic and the equatorial Atlantic during a\nRITS/CO2 cruise between 12 August and 3 September 1991. Similar measurements were also made during\na STACS cruise in September 1991. We observed a significant diurnal cycle for atmospheric DMS over the\nSouth Atlantic gyre. This cycle is in agreement with the current photochemical models that we have developed\n204","Joint Institutes-CIMAS\nfor the atmospheric sulfur cycle in the marine boundary layer. The SO2 levels measured on both cruises are\nsignificantly lower than predicted by the photochemical models for the oxidation of DMS.\nAerosols in the Marine Environment Near Iceland\nIn July 1991, we established a ground-based atmospheric chemistry sampling station on the island of\nHeimaey, off the south coast of Iceland; the station operates continuously all year long. Our data show that\nthis region is relatively free of impacts from human sources of aerosol products; in about 90% of the samples,\nsulfate and nitrate aerosol concentrations are similar to those in the pristine regions of the tropical South\nPacific. The oceanic sources of DMS clearly have a huge impact on aerosol sulfate concentrations in this\nregion. There is an extremely large seasonal cycle in the concentration of methanesulfonate (MSA), an\noxidation product of DMS; concentrations during the summer are about 100 times greater than those during\nthe winter. These data suggest that the radiative properties of the atmosphere in this region will be largely\ncontrolled by the oceanic production and emission of DMS.\nAerosol Optical Depth Measurements over the North Atlantic\nHand-held sun photometers were calibrated at Mauna Loa Observatory and then placed at three island\nstations in the North Atlantic (Barbados, Bermuda, and Tenerife) and at Miami. Data sets (in five spectral\nbands) are obtained twice every day, one set coinciding with the overpass of AVHRR.\nPlans FY 93\nAnalysis of results from cruise to the equatorical Pacific will focus on sea-air exchange rates and on flux\ncomparisons from productive (equatorial) and oligotrophic (subtropical) waters.\nWe will continue to collect daily bulk aerosol samples at the station on Heimaey. Emphasis will be placed\non the analysis and publication of the results from the samples collected during the first full year of operation.\nA major objective will be to identify the source regions for the major aerosol species on a day-to-day basis\nusing various tracers including antimony (for anthropogenic sulfur emissions) and MSA. The aerosol data\nobtained in this study will be integrated with that obtained by other groups in the North Atlantic, and will be\nused in various activities supported by the CGCP, the Climate Monitoring and Diagnostics Laboratory\n(CMDL), and the Aeronomy Laboratory (AL). An ozone and carbon monoxide monitoring station will be\nset up on Heimaey in a cooperative effort with other investigators under CGCP.\nAerosol optical depth measurements will continue throughout the year. AOD data will be compared with\naerosol chemical data and with air parcel trajectory information.\nCARBONATE STUDIES IN THE EQUATORIALPACIFIC\nThis activity is focused on the study of the carbonate system in the ocean and the relationship to the\natmosphere-ocean CO2 system. The ocean plays an important role in the global cycle of CO2, the dominant\ngreenhouse gas in the atmosphere. By studying the factors that affect the carbonate/CO2 system in the ocean,\nwe will develop a better understanding of the part that the oceans play in the atmosphere/ocean balance of\nthe global CO2 cycle, especially the degree to which the oceans can serve as a sink for anthropogenic CO2.\n205","Accomplishments FY 92\nUniversity of Miami personnel participated in three legs of the NOAA Joint Global Ocean Flux Study\n(JGOFS) in the equatorial Pacific. Our group was responsible for making high-precision measurements of\ntotal alkalinity of all the samples collected. Our total alkalinity results, when combined with measurements\nof pH, TCO2, and pCO2 by other groups, yield an internally consistent set of thermodynamic parameters for\nthe CO2 system in this region. The combined studies were the first to demonstrate this internal consistency\nbetween different measures of the CO2 system state.\nPlans FY 93\nWe will participate in three more cruises in the equatorial Pacific in the fall of 1992. These data, combined\nwith the earlier work, will be used to completely characterize the CO2 system in the equatorial Pacific during\nand around an El Niño event.\nRADIOTRACER ANALYSES\nRadiotracers provide important data for understanding oceanic mixing and transport processes. Beginning\nin 1992, the University of Miami Tritium Laboratory provided radiocarbon measurements to the\nscientific community of WOCE as well as some analyses of tritium and helium 3 for ACCP studies.\nAccomplishments FY 92\nOf 273 radiocarbon samples received from a number of Atlantic cruises, 167 have been analyzed. An\nadditional 416 radiocarbon samples were collected during Pacific cruises. Tritium/helium samples were\ncollected on a trans-Atlantic cruise of the R/V Baldridge in August 1992.\nPlans FY 93\nWe will complete the radiocarbon measurements on the samples received from FY 92 cruises.\nFISHERIES ECOLOGY AND ECOSYSTEM DYNAMICS\nCIMAS activities under this theme are organized in the Southeast Florida and Caribbean Recruitment\n(SEFCAR) study and aim to provide information and modeling approaches that will assist fisheries managers\nin the development of efficient management practices. In SEFCAR, field studies of physical processes are\nclosely integrated with biological sampling to clarify the impact of transport processes on the distribution\nand abundance of target species larvae as well as of the zooplankton that serve as larval food. The physical\nstudies include current measurements from standard moored instrumentation plus bottom-mounted ADCP\nobservations and shipboard hydrographic surveys.\n206","Joint Institutes-CIMAS\nThe physical observations are integrated with a transport model to provide a framework for interpretation\nof the biological data. The biological field work is complemented by laboratory studies of the rearing of larvae\nfor identification purposes, and by studies of larval feeding behavior and growth rates as well as time-of-\nsettling from free-swimming to bottom-attached behavior. A complementary biochemical genetic analysis\neffort is aimed at elucidating the degree to which local recruitment of spiny lobsters and snappers relies on\ngeographically disperse populations as sources for larvae and at assisting in the species identification of larval\ncollections.\nAccomplishments FY 92\nField investigations were carried out in a snapper spawning area near the Dry Tortugas. The charac-\nterization of transport patterns was facilitated by coordination with a year-long regional circulation study\nconducted by the Minerals Management Service of the U.S. Department of the Interior.\nOn the basis of our field studies, we now have a good understanding of the details of the regional\nretention/recirculation zone that extends from the southwest Florida Shelf region around the tip of the\npeninsula (the Tortugas Gyre). We established that there is a close linkage between transport fluctuations in\nthis region and the formation of a smaller scale Pourtales Gyre in the Straits of Florida. A numerical model\nis being used to study the circulation in these gyres and in local onshore surface Ekman transports and to\nshow how these might act to concentrate fish and lobster larvae for recruitment into the Florida Keys coral\nreefs. Steps have been taken to expand this modeling activity to accommodate parallel efforts in RSMAS to\nassess the potential impact of pollution and maritime oil spills on the ecology of the Keys National Marine\nSanctuary.\nFocusing on grunts and serranids, we continued laboratory work with 15 reef fish species that were reared\nfor larval identification. Growth rates were determined for five species for at least two temperatures. Vertical\nswimming behavior was measured for two species from the time of hatch to 20 days after hatch; these data\nwill be used in the modeling component of the program. Otoliths of known age are available from all these\nspecies; these provide a basis for age distribution assessments.\nAnalyses of nearly 250 adult lobsters from 10 sites throughout the Caribbean basin indicate a very large\neffective population size and substantial genetic interchange. These results are consistent with the hypothesis\nthat recruitment takes place over long distances to southeast Florida; however, these results cannot be used\nto prove the hypothesis.\nWe have developed a polymerase chain reaction (PCR) and rDNA based probe that uses only minute\nquantities of tissue. This probe facilitates differentiation at the species level of four morphologically\nhard-to-distinguish local lobster species larvae. This procedure allows rapid and accurate assessment of the\nspecies distribution of larvae in plankton tows.\nWe also developed a biochemical indicator of the physical condition of snappers and protein electrophoretic\nmethods to distinguish between species of snappers. We initiated work on the development of a mtDNA\nmethod to identify snapper species.\nPlans FY 93\nThe SEFCAR activity in FY 93 will emphasize the synthesis and interpretation of results from several\nyears of field and laboratory studies. We will continue a limited scale followup on the earlier physical\noceanographic studies using some moored current meters and satellite-tracked drifters. The objective is to\nenhance the documentation of average state and variability of the stratification and circulation patterns in the\n207","Florida Keys and Dry Tortugas regions. These data are necessary for the development of models of regional\nretention and growth conditions for larval stages of the reef fishes and spiny lobster.\nWe will begin field experiments that focus on the relationship of larval distributions to transport patterns\non scales where the larval behavior is expected to exert direct influence on larval survival. To this end we\nwill conduct a distribution survey using real-time guidance derived from an HF radar current mapping system.\nThe current mapping system (Ocean Surface Current Radar, OSCR) provides kilometer-scale (or finer)\nhorizontal resolution on a 40 km by 40 km region in real time at 20-minute intervals. By combing the guidance\nfrom OSCR with accurate positioning using Global Positioning System (GPS) navigation tools, we can\naccurately lay out sampling tracks across submesoscale eddies and fronts. This will allow us to significantly\nreduce the uncertainty in the joint diagnostics of physical and biological variability. The OSCR system was\nacquired by the University of Miami in October 1992 as an investment in a new approach to studies of coastal\nmarine processes, and it is expected to become a mainstay in the design of future experiments.\nThe biological component of the program will concentrate on the analysis of samples and data obtained\nduring cruises in previous years, including chlorophyll, nutrient, and zooplankton data. We will continue to\nrefine the larval identification guides of important fishery species such as the snappers and expand the\nlaboratory studies of temperature effects on growth. We will continue field work with light traps to monitor\nthe effects of oceanographic variability on the behavior and settlement of reef fishes, especially groupers and\nsnappers. Our library of validated otoliths will be used to examine the birth date distributions of two species\nof reef fishes, Hypoplectrus unicolor and Lutjanus synagris. The genetic analysis work on lobsters will be\nconcluded with analysis of settled juveniles. These will be used for comparison with the adult populations to\nconfirm the hypothesis that the Florida stock recruits originate over a wide area. The development of mtDNA\nbased identification of selected snapper species will be completed, and a Caribbean-wide survey of genetic\nvariation in adult snappers will be initiated.\nTHE JOINT INSTITUTE FOR STUDY OF THE\nATMOSPHERE AND OCEAN\nSeattle, Washington\n(206) 545-2585\nJ. Michael Wallace, Director\nThe Joint Institute for Study of the Atmosphere and Ocean (JISAO) fosters collaboration between NOAA\nand the University of Washington, Department of Atmospheric Sciences and School of Oceanography. The\nDirector reports to the Vice Provost for Research. The 25 Senior Fellows who constitute the ongoing\nmembership of the Institute are almost evenly divided between University faculty and NOAA/Pacific Marine\nEnvironmental Laboratory (PMEL) staff, who hold affiliate faculty appointments in the University. JISAO\nis governed by a council whose members are selected from among the Senior Fellows.\nJISAO emphasizes four core research areas: climate, environmental chemistry, estuaries, and fish stock\nrecruitment. Of these four areas, only climate has enjoyed the benefit of ongoing block funding. Fifteen\nSenior Fellows are involved in various aspects of climate research. Most of the visitors and all but two of\nthe postdoctoral fellows who have been funded through this program over the past 13 years have had primary\ninterests in climate. Five Senior Fellows are currently involved in the Environmental Chemistry core\nprogram. The main research themes have been marine aspects of the carbon dioxide problem, organic carbon\ndynamics, and chemical processes involving the deposition of heavy metals. The former theme is closely\nrelated to certain aspects of the climate research in JISAO, and the latter to the estuarine research.\n208","Joint Institutes-JISAO\nDuring the past 4 years JISAO has played an active role in University and NOAA efforts to establish\ninterdisciplinary research on the global climate system and its sensitivity to human activities. The Institute's\nExperimental Climate Forecast Center (ECFC) falls within the scope of this effort.\nJISAO's climate research focuses on large-scale atmosphere-ocean interaction in the tropics, and\nplanetary-scale wave-mean flow interaction. JISAO has substantially increased the level of activity in these\nareas at the University, and it has promoted collaboration between PMEL scientists involved in Equatorial\nPacific Ocean Climate Studies (EPOCS) field programs and University scientists and postdoctoral fellows\ninvolved in theoretical and modeling studies of the phenomena under investigation in EPOCS. It has also\nresulted in increased interaction between atmospheric scientists and physical oceanographers of the Univer-\nsity faculty.\nThe Institute's core (Task 1) program, to which the University contributes by waiving indirect costs,\nsupports postdoctoral fellows on 2-year appointments; postdoctoral fellows whose salary is paid either\nthrough fellowships, grants from their home institution, or grants and contracts from national agencies;\ndistinguished visitors; and a varying number of short-term visitors. JISAO's Task II and Task III programs\nserve as a vehicle for funding research scientists, graduate research assistants, and grants and contracts that\nsupport either collaborative research efforts between NOAA and University scientists or other research in\nareas compatible with the Institute's major research themes.\nAccomplishments FY 92\nResearch Activities\nTask I\nDuring 1992, JISAO continued to collaborate with the Goddard Institute for Space Sciences to simulate\ngeographic variations in atmospheric 14 CO2 using a three-dimensional global tracer transport model. This\nwork is funded in part by a grant from the NOAA Climate and Global Change Program. Two manuscripts\nbased on this research are in preparation.\nThe modeling results help define the strength and geographic distribution of natural (preindustrial) oceanic\nCO2 sources and sinks, a subject of intense debate with implications for the ocean's role in removing\nanthropogenic CO2. The polar oceans appear to have been weaker CO2 sinks in preindustrial (and current)\ntimes than has sometimes been conjectured. The natural difference between annual average circumpolar\nsurface water and atmospheric pCO2 is interpreted to have been about-105 ppm (corresponding to an ocean\nuptake of 1.00.5 gigaton C per year) and the natural meridional atmospheric CO2 gradient (45°N to 45°S) is\ninferred to have been about + 1 ppm.\nUsing a box-diffusion global 14 C model, ocean surface 14C variations for the last 10,000 years were\nsimulated as an aid to calibration of marine samples. The spectral characteristics of the 10,000-year tree-ring\n14C record were identified, as well as the corresponding model-derived 14C production rate history (a proxy\nfor solar activity). The high-resolution 14C simulations helped define the extent of carbon, solar, and\ngeomagnetic variations during recent periods of climate change (e.g., Younger Dryas, glacial/interglacial,\nand the Holocene).\nWork continued on the development of a new global atmosphere model for climate studies in collaboration\nwith Lamont-Doherty Geological Observatory in New York. The model solution technique proceeds through\ndecomposition of the linearized primitive equations into model normal modes. Forced ordinary differential\nequations governing the amplitude of each normal mode are then solved analytically. Much of the recent\nyear has been spent developing the model's radiation code. A nonisothermal emissivity scheme was\n209","implemented that explicitly accounts for the different absorption bands of water vapor, together with\ncontinuum and far wing absorption. The scheme follows that used in the National Center for Atmospheric\nResearch circulation model but, in keeping with our climate modeling philosophy, considerable effort was\nmade to speed the code and allow accurate computation of radiative fluxes within a low vertical resolution\nformat.\nThe major achievement of the collaborative effort between the University of Washington and PMEL was\nthe measurement of chlorofluorocarbon (CFC) distributions on the World Ocean Circulation Experiment\n(WOCE) hydrogaphic section S4 in the Pacific Ocean. JISAO and PMEL scientists participated in this\nsuccessful expedition aboard the Russian research vessel Akademik loffe, using the analytical system and\nportable laboratory of the PMEL CFC group. Trichlorofluoromethane (F-11) and dichlorodifluoromethane\n(F-12) concentrations were measured in greater than 60% of the hydrographic samples. The dissolved\nconcentrations of F-113 and carbon tetrachloride were also measured at every fourth station during this\nexpedition.\nProgress has been made in the determination of F-113 solubilities. These experiments are necessary to all\ninterpretations of dissolved F-113 concentrations.\nA two-dimensional model for equatorial undercurrents was developed and used to examine dynamic and\nheat balances of the equatorial undercurrent. Model results show that the weaker undercurrent in the Atlantic\nrelative to the undercurrent in the Pacific can be explained by a more surface-confined zonal pressure gradient\nand a shallower thermocline in the Atlantic than in the Pacific. Also, the phenomenon in which the\nundercurrent closely follows the thermocline in vertical position is proposed to be determined by the advective\nheat balance: the undercurrent is in the thermocline when advective heat transports cancel. Other research\nincluded (1) development of a multilayer ocean model using isentropic vertical coordinate for studying\noceanic ventilation processes in climate change, (2) model experimental studies of oceanic variability on\ndecade and century time scale with Bryan-Cox model, and (3) model studies of equatorial ocean dynamics\nand related variability.\nExperimental Climate Forecast Center\nThe ECFC investigates the existence of and mechanisms for predictability of climate variations on time\nscales of a season to 100 years and beyond. Since most long-term climate variability involves the ocean, the\nocean and its role in climate form the major thrust of the work of the ECFC.\nOn seasonal to interannual time scales, the El Niño-Southem Oscillation (ENSO) in the tropics is the\ndominant mode of nonseasonal variability. The ECFC developed and maintains several simplified coupled\natmosphere-ocean models of the ENSO phenomenon and concentrates on understanding the instability\nmechanisms for the oscillation and on error growth and predictability in the models.\nOn longer time scales, the ocean's thermohaline circulation has relatively long time scales. The ECFC\nmaintains and runs several simplified general circulation sector models of the thermohaline circulation and\ninvestigates the mechanisms for thermohaline variability and its effect on climate.\nTOGA TAO Project\nThe implementation of the Tropical Ocean Global Atmosphere (TOGA) Tropical Atmosphere Ocean\n(TAO) array has been proceeding nearly on schedule: By 1 January 1992, 33 buoys were in place in the\nequatorial waveguide, and the number will reach 53 by the end of the year. As the array takes shape, the\n210","Joint Institutes-JISAC\nsurface wind field and the subsurface thermal structure in the equatorial Pacific are being observed with an\nincreasing level of clarity and detail.\nCollaborative Research at JISAO\nTask II\nWater property and volume transport from numerous Shelikof area conductivity, temperature, and depth\n(CTD) data were obtained and analyzed, as were Gulf of Alaska atmospheric data, and correlations were\nmade with calculated transports from Lower Cook Inlet ice cover data.\nA case study of coastal winds in Alaska was completed for the Gulf of Alaska Fisheries Oceanography\nCoordinated Investigations (FOCI), as was a climatological study of the wind forcing of the Bering Sea for\nthe Bering Sea FOCI. An observational study of the tropical boundary layer in the eastern equatorial Pacific\nwas completed for EPOCS. A case study of a pair of landfalling storms in the Gulf of Alaska was started;\nproposals were initiated for additional research on the effects of topogaphy on West Coast weather.\nJISAO participated in research with the PMEL Tsunami Project, which conducts observational and\ntheoretical investigations of the dynamics of tsunami generation, propagation, and coastal inundation. The\nproject emphasizes a vigorous field measurement program using high-resolution, deep ocean bottom pressure\nrecorders. An error analysis of the standard calibration procedures was done for these gauges, assuming static\npressure loads and constant ambient temperature conditions.\nInitial work on the dynamics of tsunami generation involved developing an improved method of converting\nanalog coastal tide gauge records to digital form. These new procedures were used to produce the digital tide\ngauge data sets for two small tsunamis currently under study.\nProcessing of underway temperature and pCO2 distributions in the equatorial Pacific and TCO2 data from\nnew SOMMA TCO2 analyzers included developing programs for data collection, reduction, and archival. A\nnew automated pCO2 analyzer system was developed for a joint NOAA/Joint Global Ocean Flux Study\n(JGOFS) cruise in the equatorial Pacific aboard the NOAA ship Malcolm Baldrige.\nThe Arctic program involves basic research in oceanography, meteorology, sea ice physics, and climatol-\nogy throughout the Arctic. Major emphases at present are the following:\nCirculation and climatology of the western Arctic (What is the Pacific influence on the Arctic?)\nThe outflow of fresh water from the Arctic Ocean (What is the variability of the high-latitude fresh\nwater flux into the Atlantic and what is its effect on the global overturning cell?)\nSea ice and convection in the Greenland Sea (How does ice behave in a convective ocean?)\nOcean climate variability in the Polar Basin (What is the variability of the ice cover, ocean structure,\nvelocity field, and sedimentation rates within the Arctic Ocean?)\nAn exceptionally large aggregate of measurements was undertaken in support of these issues this year,\nincluding four oceanographic cruises on vessels of Canada, the Federal Republic of Germany, Norway, and\nthe United States, and an aircraft-supported Canada-U.S. ice operation. In the Chukchi Sea alone, 13\nyear-long instrumented moorings were recovered, providing a well-calibrated data set of excellent quality\nand uniquely broad coverage. These collective efforts will significantly improve the understanding of the\nrole of the Arctic in the global climate system.\nFERRET, a computer program for the interactive visualization and analysis of gridded data sets, has now\nbeen made available via anonymous File Transfer Protocol (FTP) for DEC, Sun, and Silicon Graphics UNIX\nscientific workstations. A subset of the Thermal Modeling and Analysis Project (TMAP) data collection is\ndistributed with the software, and we plan to improve access to the collection this year.\n211","Analysis of the first year of the Special Sensor Microwave/Imager (SSM/I) gridded wind field yielded\ninteresting results. Year two will be available soon and will provide us with further opportunity for study of\nwesterly wind variability and comparison with in situ observations.\nAnalytical instruments were developed for the high-precision measurement of dissolved oxygen and\nnutrients in seawater samples in the laboratory and at sea, as well as for assisting with ongoing studies of\ndissolved gases in seawater.\nResearchusing a Semispectral Primitive Equation Model (SPEM) focused on developing proper boundary\nconditions, mixing terms, and forcing for this three-dimensional model. The spatial resolution of the model\nhas been gradually increased, with the goal of ultimately addressing the dynamics and statistics of mesoscale\neddy formation and decay near Shelikof Strait. Such eddies are of special interest to FOCI researchers due\nto their impacts on survival of larval fish in this region.\nData from several past field projects (CITE-3 and SAGA-3) were analyzed. An experimental and\nmeteorological overview paper of the SAGA-3 experiment was submitted for publication. Instrumentation\nto measure atmospheric and oceanic carbon monoxide was developed and used on the International Global\nAtmospheric Chemistry-Marine Aerosol and Gas Exchange Program (IGAC-MAGE) cruise aboard the R/V\nJohn Vickers in the equatorial Pacific (mid-February through March 1992).\nWork associated with the ENSO phenomenon is under way to process and analyze wind, current,\ntemperature and salinity time series data from TOGA TAO moorings in the equatorial Pacific, as well as\ntemperature and position data from drifting thermistor chains, circulation drifter data, shipboard velocity data,\nCTD data, and expendable bathythermograph (XBT) data.\nThe long time series (more than 10 years) of ocean temperature and salinity measurements made by\nNOAA's EPOCS program at 0°, 110°W and along this longitude was analyzed, considering the mean,\ninterannual, and seasonal variability. An interesting feature is the southward-flowing undercurrent on the\nEquator throughout much of the year in response to strong meridional winds that induce a meridional pressure\ngradient in the ocean.\nThe links between particulate mass derived from dimethylsulfide, the formation and growth of condensa-\ntion nuclei, and the activation of the latter to form cloud condensation nuclei (CCN) are being studied,\nspecifically with regard to the design and improvement of techniques for the collection and chemical analysis\nof size-segregated particle samples. These techniques were tested and used extensively during the\nIGAC-MAGE cruise from Los Angeles to Nuku Hiva; they provided an opportunity to study the remote\natmosphere during relatively stable meteorological conditions.\nA model provided by the Naval Research Laboratory was implemented on the ERL Cray Y-MP at\nGaithersburg, Maryland. Model results are being analyzed for the Bering Sea. The first phase of the Bering\nSea analysis was completed. The three-layer model, with realistic bathymetry and coastlines, was forced by\nthe throughput of the Alaskan Stream and monthly climatological winds. The overall circulation conforms\nwith prior knowledge of the region, but some novel features have emerged as a result of the fine resolution\nof the model. In the next phase the model will be forced by daily winds. The model studies complement\nparallel investigations using satellite altimetry, satellite-tracked buoys, and ship-based observations. The\nresults to date are incorporated in a paper to be submitted for publication.\nData from the TOGA TAO array were used to examine spatial coherence scales and temporal sampling\nrequirements to adequately represent equatorial Pacific winds. This study is now being expanded to include\nsurface and subsurface oceanic temperature. Results of the wind analysis were accepted for publication.\n212","Joint Institutes-JISAO\nTask III\nJISAO Projects\nResearch activities included studies on interannual variability of the atmosphere-ocean system, with\nemphasis on the midlatitudes of the Northern Hemisphere and the tropical Pacific. Work is proceeding on\nfive subprojects, supported under a new (3-year) grant from NOAA. These include the following:\nModeling studies of the processes that are integral to the ENSO phenomenon.\nTheoretical studies of the predictability of ENSO using neural network structures.\nExamination of mechanisms for secular variation in the ENSO phenomena.\nDevelopment of a second generation of optimal physics models for ENSO to examine explicitly the\neffect of higher order ocean modes and atmospheric boundary layer processes on the ENSO\nphenomenon.\nSimulation and analysis of coordinated atmosphere-ocean interannual variability in the North Pacific.\nA proposal has been submitted to NOAA to significantly expand the midlatitude component on the\naforementioned project, specifically to examine the mechanisms of interannual variability in the North\nAtlantic atmosphere-ocean system, and test the hypothesis that a significant portion of this variance is\ncoordinated by like interactions in the North Pacific, teleconnected over North America.\nResearch is under way to quantify the influence of aerosol particles on climate, with special emphasis on\nnaturally occurring sulfate aerosol in the remote marine planetary boundary layer. The approach involves\ndeveloping methods for the simultaneous measurement of the key aerosol, optical and cloud-nucleating\nproperties. The main field site is the University of Washington Cheeka Peak Research Station near Neah\nBay, Washington.\nSpecific accomplishments during the first 9 months of funding include the following:\nDesign and purchase of computer and data acquisition system and remote communication software\nand hardware link from the University to Cheeka Peak.\nDesign and construction of two-stage impactors.\nDesign of the inlet and sample distribution system for the Cheeka Peak and other NOAA Climate\nMonitoring and Diagnostics Laboratory (CMDL) stations.\nDesign and manufacture of filter cassette.\nUpgrade of the Cheeka Peak Research Station site.\nThe optimal interpretation of the recent measurements of the new transient tracer F-113 requires a precise\nknowledge of the solubility of this halocarbon as a function of salinity and temperature encountered in the\nnatural ocean. A novel system for making solubility measurements with very high precision has been\ndeveloped and tested. Serious problems of blank contamination and appropriate gas standards have been\novercome, and the measurement program of solubility determinations for F-113 is under way.\nWork on the midwinter suppression of baroclinic wave activity in the Pacific Ocean storm track was\ncompleted and a paper was accepted for publication.\nData collected during the spring 1991 Pacific Sulfur/Stratus Investigation (PSI) project with an early type\nof CCN counter were analyzed, and a month of data was collected during the IGAC-MAGE 1992 equatorial\nPacific cruise using a state of the art commercial CCN counter.\nUnder a grant from the NOAA Climate and Global Change Program, geographic and temporal variations\n14\nin atmospheric and oceanic CO2 were simulated using a hierarchy of global transport models (box-diffusion,\natmosphere-ocean general circulation). Two objectives are to constrain the natural (preanthropogenic)\n213","geographic distribution of surface ocean pCO2 and to reproduce isotopic carbon variations during climate\ntransitions (e.g., Younger Dryas).\nPlans FY 93\nTOGA TAO Project\nFunding has been requested to continue to build computing capability that will serve the needs of\nthe director, visitors, and JISAO Senior Fellows associated with the TOGA TAO project both at\nJISAO and PMEL. The 10 workstations requested will be fully compatible with PMEL, which will\nbe developing software for displaying and manipulating data from the array.\nConsortium Activities\nIn collaboration with the Geophysical Fluid Dynamics Laboratory, JISAO will continue to be funded\nand further experiments will be targeted at understanding the abrupt transitions between wintertime\nand summertime climates are already under way.\nTOGA\nA JISAO senior fellow will serve on the Task Group on the Implementation of a Multinational\nNational Research Institute for Climate Prediction. The research institute will be located in the\nUnited States, and the University of Washington plans to submit a proposal to have it located in\nSeattle.\nExperimental Climate Forecast Center\nResearch will focus on the mechanisms of predictability of the climate system on time scales of a\nseason to 100 years, in particular those mechanisms involving the oceans.\nJISAO Projects\nThe remaining tasks are to test the sampling and remote control system locally in laboratories at the\nUniversity of Washington and then to install the system at Cheeka Peak during June and July 1993.\nThe system is expected to be in operation during August and routine collection of data and samples\nshould be under way by September.\nMajor tasks for the upcoming year are to maintain the sampling system, integrate and analyze the\ndata, and conduct intensive aerosol experiments at Cheeka Peak.\n214","Joint Institutes-JIMAR\nJOINT INSTITUTE FOR MARINE AND ATMOSPHERIC RESEARCH\nUniversity of Hawaii, Manoa\n(808) 956-8003\nDennis W. Moore, Director\nThe Joint Institute for Marine and Atmospheric Research (JIMAR) was formed in 1977 by a Memorandum\nof Understanding between NOAA and the University of Hawaii. JIMAR is located at the University of Hawaii\nat Manoa and is part of the School of Ocean and Earth Science and Technology. The principal research\ninterests of JIMAR are equatorial oceanography, climate and global change, tsunamis, and fisheries\noceanography.\nAccomplishments FY 92\nEquatorial Oceanography and Climate\nHawaiian Ocean Time Series station\nTime series work in support of World Ocean Circulation Experiment (WOCE) and Joint Global Ocean\nFlux Study (JGOFS) has continued. Cruises are made approximately once a month to a station 100 km north\nof Oahu, which is occupied for 3 days. Measurements include hydrography, water column chemistry, primary\nproduction, and sedimentation rates. The program is now in its fourth year. A 3-year record of dissolved\ninorganic carbon and alkalinity in the surface ocean has been assembled, giving an estimate of the annual\ncycle of CO2 exchange across the sea surface. Five inverted echo sounders (IES) were recovered at the\nHawaiian Ocean Time Series site, and four more were deployed. Comparison with hydrographic data shows\nIES travel time is well correlated with dynamic height. The IES data can be used to estimate overall dynamic\nheight variability between cruises.\nData from the Western Equatorial Pacific Ocean Circulation Study (WEPOCS) were analyzed. A statistical\nanalysis of water mass properties was completed and submitted for publication. Low-salinity intermediate\nwater off the Mindinao coast is being studied in relation to the boundary between the tropical and subtropical\ngyres.\nTide, pressure gauge, and IES data from the Line Island Array are being analyzed, and a manuscript\ndescribing this data set is in progress.\nDirect measurements of ocean currents were made using Acoustic Doppler Current Profilers (ADCPs) on\nthe WOCE Hydrographic Program sections in the Pacific Ocean. A lowered ADCP was used to measure\ncurrents throughout the water columns in equatorial regions.\nThe Indo-Pacific Sea Level Network (IPSLN) now maintains instruments at 52 sites in 27 countries, and\nthree new Indian Ocean sites were added during FY 92. The Tropical Ocean Global Atmosphere (TOGA)\nSea Level Center (SLC) now has 1827 station years of data from 207 stations. The International Global\nOcean Services System (IGOSS) Sea Level Project in the Pacific (SLP-Pac) provides monthly maps of\nPacific sea-level topography and anomalies (pressure-corrected).\nData from the 1982/83 and 1986/87 Pacific warm episodes El Niño-Southern Oscillation (ENSO) events\nwere studied using multivariate empirical orthogonal function (EOF) analysis. Differences between these\nevents and the so-called canonical model indicate that a variety of coupled processes occurring in more than\none geographic area may be important in the ENSO phenomenon.\n215","A study of the 30-60 day \"convective seesaw\" between the tropical Indian and western Pacific Oceans\nwas completed.\nModeling studies of the deep thermally driven equatorial mean circulation continued.\nTOGA COARE (Coupled Ocean-Atmosphere Response Experiment) preparations continued. JIMAR\nscientists participated in a number of TOGA Tropical Atmosphere Ocean (TAO) cruises.\nJIMAR scientists are involved in NASA's Topographic Experiment (TOPEX) Poseidon, Earth Observing\nSystem (EOS), and Tropical Rainfall Measuring Mission (TRMM) projects.\nFisheries Oceanography\nStudies of flow-topography interactions around oceanic islands continued. A manuscript on mesoscale\noceanography around Palmyra Atoll was completed.\nWork on spiny lobster recruitment variation and oceanographic conditions in the Northwest Hawaiian\nIslands, using satellite altimetry and sea-level gauge data, continued.\nA workshop was held to plan for a major research undertaking on pelagic fisheries (tuna and billfish) in\nsupport of the Western Pacific Regional Fisheries Management Council.\nTsunami Research\nModeling\nThe flooding of Hilo, Hawaii, by the tsunamis of 1 April 1946, 23 May 1960, and 28 March 1964 was\nmodeled numerically. The calculated inundation limits agree reasonably well with the actual observations.\nAnalysis of T-phase data\nA major study of low-frequency acoustic energy (T-phase) in the ocean, using data from an array of\nhydrophones at Wake Island and another at Kaneohe, was carried out. T-phase spectral strength is correlated\nwith seismic movement. Earthquakes with large T-phase spectral strengths seem to generate large tsunamis.\nPlans FY 93\nEquatorial Oceanography and Climate\nHawaiian Ocean Time Series observations and analysis will continue. A proposal for the next 5 years\nof the program will be submitted.\nWEPOCS analysis and publication of results will continue.\nThe COARE Intensive Observing Period will begin in December 1992, and several JIMAR scientists\nwill participate.\nA workshop will be held on application of ENSO predictions by local (state and Pacific Island nation)\ngovernments. An international TOGA TAO implementation panel will meet at JIMAR. Plans\ncontinue for enhanced cooperation with the Honolulu Forecast Office of the National Weather Service\n(NWS).\n216","Joint Institutes-JIMAR\nThe IPSLN, TOGA SLC, and the International Global Ocean Services System (IGOSS) SLP-Pac\nwill all continue.\nPlans for a Hawaii Center for Climate Monitoring in the Pacific are under discussion.\nModeling studies of tropical ocean circulation and variability of the atmosphere and ocean will\ncontinue.\nFisheries Oceanography\nA workshop on interdecadal-scale variation in the Northwest Hawaiian Island ecosystem is planned.\nFurther studies on climate and ecosystem variability in this area will be carried out.\nThe major components of the JIMAR Pelagic Fisheries Program (first year) will be determined and\na proposal package will be submitted to NOAA.\nTsunami Research\nThe Hilo harbor model will be run using a finer grid to see if further improvements in predicted\nrun-up heights and inundation limits can be obtained. Tsunami inundation models will be run for\nthe Humboldt Bay and Crescent City areas in California.\nFurther studies on the use of T-phase data will be carried out to determine the usefulness of T-phase\nas a real-time tsunami prediction tool.\n217","","APPENDIX: Acronyms and Initialisms\nA&P\nAnalysis and Prediction (FSL branch)\nAirborne Arctic Stratospheric Expedition\nAASE\nARINC Communications Addressing and Reporting System\nACARS\nAirborne Chromatograph for Atmospheric Trace Species\nACATS\nAtlantic Climate Change Program\nACCP\nACE\n[NASA satellite]\nAdvanced Computing Group (FSL)\nACG\nAcoustic Doppler Current Profiler\nADCP\nAdvanced Development Facility (FSL branch)\nADF\nAtmospheric Environment Service (Canada)\nAES\nAlaska Fisheries Center (NMFS)\nAFC\nArctic Gas and Aerosol Sampling Program\nAGASP\nAviation Gridded Forecast System\nAGFS\nAGU\nAmerican Geophysical Union\nAI\nartificial intelligence\nAtmospheric Integrated Research Monitoring Network\nAIRMON\nAIV\naviation-impact variable\nAeronomy Laboratory (ERL)\nAL\nActive Magnetospheric Particle Tracer Explorer [satellite]\nAMPTE\nAtmospheric Nutrient Input to Coastal Areas [project]\nANICA\nAOD\naerosol optical depth\nAtlantic Oceanographic and Meteorological Laboratory (ERL)\nAOML\nAtmospheric and Ocean Sciences [Program]\nAOS\n[East] Asian-[North] Pacific Regional Experiment\nAPARE\nAssessment and Remediation of Contaminated Sediments [project]\nARCS\nARINC\nAeronautical Radio Incorporated\nAir Resources Laboratory (ERL)\nARL\nAtmospheric Radiation Measurements [DOE Program]\nARM\nARO\nArmy Research Office\nAdvanced Regional Prediction System\nARPS\nAerosol Research Section (ARL)\nARS\nAir Route Traffic Control Center (FAA)\nARTCC\nAtmospheric Studies in Complex Terrain\nASCOT\nASD\naircraft situation display\nAtmospheric Science Laboratory (Army)\nASL\nAtmospheric Sciences Modeling Division (ARL)\nASMD\nAutomated Surface Observing System\nASOS\nAtlantic Stratocumulus Transition Experiment\nASTEX\nAtmospheric Transport and Dispersion [model]\nATAD\nAir Traffic Control (FAA)\nATC\nAtmospheric Turbulence and Diffusion Division (ARL)\nATDD\nAdvanced Traffic Management System\nATMS\nAcoustic Thermometry of Ocean Climate [program]\nATOC\nAdvanced Very High Resolution Radiometer\nAVHRR\nAirborne Visible and Infrared Imaging Spectrometer\nAVIRIS\nAdvanced Visualization System [program]\nAVS\n219","AWIPS\nAdvanced Weather Interactive Processing System\nBAO\nBoulder Atmospheric Observatory\nBCF\nbromochlorodifluoromethane\nBOREAS\nBoreal Ecosystem-Atmosphere Study\nBPR\nbottom pressure recorder\nBSRN\nBaseline Surface Radiation Network\nCAC\nClimate Analysis Center (NOAA)\nCaPE\nCape Kennedy Precipitation Experiment\nCAPS\nCenter for Analysis and Prediction of Storms\nCART\nCloud and Radiation Testbed [DOE network]\nCASTNET\nClean Air Status and Trends Network (EPA)\nCBL\nconvective boundary layer\nCBOS\nChesapeake Bay Observing System\nCCOPE\nCooperative Convective Precipitation Experiment\nCEPEX\nCentral Equatorial Pacific Experiment\nCFC\nchlorofluorocarbon\nCFWSU\nCentral Flow Weather Service Unit (FAA)\nCGCP\nClimate and Global Change Program (NOAA)\nCHARM\nCoupled Hydrologic Atmospheric Research Model\nCILER\nCooperative Institute for Limnology and Ecosystems Research\nCIMAS\nCooperative Institute for Marine and Atmospheric Studies\nCIMMS\nCooperative Institute for Mesoscale Meteorological Studies\nCIMRS\nCooperative Institute for Marine Resources Studies\nCIRA\nCooperative Institute for Research in the Atmosphere\nCIRES\nCooperative Institute for Research in Environmental Sciences\nCLARET\nCloud Lidar and Radar Exploratory Test\nCLASS\nCross-chain Loran Atmospheric Sounding System\nCLIPER\nclimatology and persistence [model]\nCMDL\nClimate Monitoring and Diagnostics Laboratory\nCME\nCommunity Modeling Effort [model]\nCME\ncoronal mass ejection\nCMIST\nConfiguration Management Integrated Support Tool\nCN\ncondensation nucleus\nCOADS\nComprehensive Ocean-Atmosphere Data Set\nCOARE\nCoupled Ocean-Atmosphere Response Experiment (TOGA)\nCOMET\nCooperative Program for Operational Meteorology, Education, and Training (NCAR)\nCOPS-89\nCooperative Oklahoma P-3 Studies-1989\nCOPS-91\nCoperative Oklahoma Profiler Studies-1991\nCPP\nCryospheric and Polar Processes\nCRD\nClimate Research Division\nC-SCAT\nC-band Scatterometer\nCSI\nconditional symmetric instability\nCSIRO\nCommonwealth Scientific and Industrial Research Organization (Australia)\nCSU\nColorado State University\nCSU-RAMS\nCSU Regional Atmospheric Modeling System\n220","Acronyms and Initialisms\nCTD\nconductivity, temperature, depth\nCU\nUniversity of Colorado\nCWB\nCentral Weather Bureau (Taiwan)\nCWSU\nCentral Weather Service Unit (FAA)\nDARE-II\nDenver AWIPS Risk Reduction and Requirements Evaluation [workstation]\nDARPA\nDefense Advanced Research Projects Agency (DOD)\nDD\nDemonstration Division (FSL)\nDDIM\nDry Deposition Inferential Method\nDifferential Absorption Lidar\nDIAL\nDMS\ndimethylsulfide\nDMSP\nDefense Meteorological Satellite Program (Air Force)\nDNSH\ndansyl hydrazone\nDOC\ndissolved organic carbon\nDOD\nDepartment of Defense\nDOE\nDepartment of Energy\nDOM\ndissolved organic matter\nDOMSAT\nDomestic Satellite\nDON\ndissolved organic nitrogen\nDRS\nData Receiving System\nDSI\ndry symmetric instability\nDWBC\nDeep Western Boundary Current\nEC-GC\nelectron capture gas chromatograph\nECMWF\nEuropean Centre for Medium-Range Weather Forecasting\nEFF\nExperimental Forecast Facility (NWS)\nEFT\nEnhanced Forecaster Tools (FSL branch)\nEMAP\nEnvironmental Monitoring and Assessment Program (EPA)\nENSO\nEl Niño-Southern Oscillation\nEOF\nempirical orthogonal function\nEOS\nEarth Observing System\nEOSDIS\nEOS Data and Information System\nEPA\nEnvironmental Protection Agency\nEPRI\nElectric Power Research Institute\nEPS\nEnergetic Particle Sensor\nEPOS\nEarthquake Phenomena Observation System\nERBE\nEarth Radiation Budget Experiment\nERICA\nExperiment on Rapidly Intensifying Cyclones over the Atlantic\nERL\nEnvironmental Research Laboratories (NOAA)\nERS\nEarth Resources Satellite\nESDIM\nEarth System Data and Information Management (NOAA)\nETH\nSwiss Federal Institute of Technology-Zurich\nEUV\nextreme ultraviolet\nFAA\nFederal Aviation Administration\nFAR\nForecast Applications Research (NSSL group)\n221","FARA\nFrench American Ridge Atlantic [program]\nFAST\nfore-aft scanning technique\nFD\nFacility Division (FSL)\nFERRET\n[interactive display and analysis system; not an acronym]\nFIBS\nField by Information Blending and Smoothing [procedure]\nFID-GC\nflame ionization detection-gas chromatography\nFIRE\nFirst ISCCP Regional Experiment\nFITS\nFile Image Transfer System [format]\nFIRS\nFourier transform Infrared Sounder\nFMO\nFlatland Meteorological Observatory\nFNOC\nFleet Numerical Oceanographic Center\nFOCI\nFisheries Oceanography Coordinated Investigations (NOAA)\nFRAQS\nFront-Range Air Quality Study\nFRC\nFront-Range Consortium\nFRD\nField Research Division (ARL)\nFRG\nForecast Research Group (FSL)\n4DDA\nfour-dimensional data assimilation [scheme]\nFRLAB\nFront Range Lidar-Aircraft-Balloon [experiment]\nFSL\nForecast Systems Laboratory (ERL)\nFTP\nFile Transfer Protocol\nGC\ngas chromatograph\nGC-MS\ngas chromatography-mass spectrometry\nGCM\ngeneral circulation model\nGCPS\nGlobal Climate Perspectives System\nGEOALERT\n[forecast]\nGEOSAT\nGeodetic Satellite\nGEWEX\nGlobal Energy and Water Cycle Experiment\nGFDL\nGeophysical Fluid Dynamics Laboratory (ERL)\nGIS\nGeographic Information System\nGLERL\nGreat Lakes Environmental Research Laboratory (ERL)\nGLFS\nGreat Lakes Forecasting System\nGMC\ngeostationary magnetopause crossing\nGOES\nGeostationary Operational Environmental Satellite\nGO3OS\nGlobal Ozone Observing System\nGPS\nGlobal Positioning System\nGRAF\nGridded Representation of Analyses and Forecasts [system]\nGRIB\nGridded Binary [data format]\nGSA\nGeneral Services Administration\nGSE\nground support equipment\nGUFMEX\nGulf of Mexico [project]\nGVaP\nGEWEX Water Vapor Project\nGWP\nglobal warming potential\nHALOE\nHalogen Occultation Experiment\nHARA\nHistorical Arctic Rawindsonde Archive\nHARP\nHawaiian Rainband Project\n222","Acronyms and Initialisms\nHCFC\nhydrochlorofluorocarbon\nHEPAD\nHigh Energy Proton and Alpha Detector\nHIFT\nHeard Island Feasibility Test\nHIRIS\nHigh Resolution Imaging Spectrometer\nHLMS\nHigh Latitude Monitoring Station\nHOC\nhydrophobic organic compound\nHPBL\nhurricane planetary boundary layer\nHPCC\nHigh Performance Computing and Communications\nHPD\nhourly precipitation data\nHPLC\nhigh performance liquid chromotography\nHRD\nHurricane Research Division (AOML)\nHY-SPLIT\nHybrid Single Particle Lagrangian Integrated Trajectories [model]\nICE\nInternational Cirrus Experiment\nIES\ninverted echo sounder\nIFA\nIntensive Flux Array\nIFREMER\nInstitut Français de Recherche pour l'Exploitation de la Mer\nIGAC-MAGE\nInternational Global Atmospheric Chemistry-Marine Aerosol and Gas Exchange [program]\nIGOSS\nInternational Global Ocean Services System\nIGM\ninterplanetary global model\nIGS\nInner Gulf Shelf\nIMPROVE\nInteragency Monitoring of Protected Visual Environments\nINEL\nIdaho National Engineering Laboratory\nINSAT\nIndian Satellite\nINTERMAGNET\n[program; not an acronym]\nIOP\nintensive operating period\nIOS\nInstitute of Ocean Sciences\nIPCC\nIntergovernmental Panel on Climate Change\nIPS\ninterplanetary scintillation\nIR\ninfrared\nISC\nIndustrial Source Complex\nISCCP\nInternational Satellite Cloud Climatology Project\nISPAN\nInformation Stream Project for AWIPS and NOAAPORT\nISS\nIntegrated Sounding System\nITCZ\nintertropical convergence zone\nIUSS\nIntegrated Underwater Surveillance System\nIUWDS\nInternational Ursigram and World Days Service\nJAMSTEC\nJapan Marine Science and Technology Agency\nJGOFS\nJoint Global Ocean Flux Study\nJIMAR\nJoint Institute for Marine and Atmospheric Research\nJISAO\nJoint Institute for Study of the Atmosphere and Ocean\nJVNTSC\nJohn Volpe National Transportation Center (FAA)\nKOFSE\nKuwait Oil Fire/Smoke Experiment\n223","LAI\nleaf area indices\nLAN\nlocal area network\nLAPS\nLocal-scale Analysis and Prediction System\nLATEX\nLouisiana-Texas oceanographic experiment\nLEADEX\nLeads Experiment\nLEIFS\nLake Erie Information Forecasting System\nLINCOM\nlinear complex terrain model\nloran\nlong-range aid to navigation\nLOWTRAN-7\n[radiative transfer model; not an acronym]\nLSDM\nLagrangian stochastic dispersion model\nMAP3S\nMultistate Atmospheric Power Production Pollution Study\nMAPS\nMesoscale Analysis and Prediction System\nMAR\nMississippi-Atchafalaya River [system]\nM-CLASS\nmobile CLASS\nMCS\nmesoscale convective system\nMCSST\nMulti-Channel SST\nMCV\nmesoscale convectively generated vortex\nMD\nModernization Division (FSL)\nMDD\nMeteorological Data Distribution\nMESODIF\n[transport and diffusion model; not an acronym]\nMETEOSAT-3\n[European Space Agency weather satellite; not an acronym]\nMFP\nmatched-field processing\nMFP\nMobile Flux Platform\nMHD\nmagnetohydrodynamic [simulation]\nMIT\nMassachusetts Institute of Technology\nMLOPEX\nMauna Loa Observatory Photochemistry Experiment\nMM4\nMesoscale Meteorological Model-Version 4\nMOA\nMemorandum of Agreement\nMOCNESS\nmultiple opening-closing net environmental sampling system\nMODELS-3\n[third-generation air quality modeling system]\nMODIS\nModerate Resolution Imaging Spectrometer\nMODTRAN\n[moderate resolution atmospheric radiance model for the infrared]\nMOHAVE\nMeasurement of Haze and Visual Effects [study]\nMOM\nModular Ocean Model\nMPP\nmassively parallel processor\nMRD\nMesoscale Research Division (NSSL)\nMRP/GS\nMississippi River Plume/Gulf Shelf\nMS\nmass spectrometer\nMSA\nmethanosulfonate\nMSU\nmicrowave sounding unit\nMWSR\nMicrowave Water Substance Radiometer\nNARE\nNorth Atlantic Regional Experiment\nNAS\nNational Airspace System\nNASA\nNational Aeronautics and Space Administration\nNAWAU\nNational Aviation Weather Advisory Unit (FAA)\n224","Acronyms and Initialisms\nNCAR\nNational Center for Atmospheric Research\nNCDC\nNational Climatic Data Center (NOAA)\nNDDN\nNational Dry Deposition Network\nNDREX\n[Doppler display and editing system; not an acronym]\nNDSC\nNetwork for the Detection of Stratospheric Change\nNDVI\nNormalized Difference Vegetation Index\nNECOP\nNutrient-Enhanced Coastal Ocean Productivity [program]\nNESDIS\nNational Environmental Satellite, Data, and Information Service (NOAA)\nNEWS\nNOAA Earth Watch Service\nNGDC\nNational Geophysical Data Center (NOAA)\nNGM\nNested Grid Model (NMC)\nNHC\nNational Hurricane Center (NOAA)\nNIST\nNational Institute of Standards and Technology\nNIWAR\nNational Institute for Water and Atmospheric Research (New Zealand)\nNMC\nNational Meteorological Center (NOAA)\nNMFS\nNational Marine Fisheries Service (NOAA)\nNMHC\nnonmethane hydrocarbon\nNOAA\nNational Oceanic and Atmospheric Administration\nNOAAPORT\n[access to NOAA real-time data base system; not an acronym]\nNOCN\nNational Ocean Communications Network\nNODC\nNational Ocean Data Center (NOAA)\nNOS\nNational Ocean Service (NOAA)\nNPS\nNational Park Service\nNRC\nNuclear Regulatory Commission\nNRL\nNaval Research Laboratory\nNSF\nNational Science Foundation\nNSIDC\nNational Snow and Ice Data Center\nNSSFC\nNational Severe Storms Forecast Center\nNSSL\nNational Severe Storms Laboratory (ERL)\nNURP\nNOAA Undersea Research Program\nNWP\nnumerical weather prediction\nNWS\nNational Weather Service (NOAA)\nNWSFO\nNWS Forecast Office\nOAR\nOceanic and Atmospheric Research (NOAA)\nODP\nozone depletion potential\nODW\nomega dropwindsonde\nOK-PRE-STORM\nOklahoma-Kansas PRE-STORM\nOLR\noutgoing longwave radiation\nOLS\nOperational Linescane System (DOD)\nONR\nOffice of Naval Research\nOSCR\nOcean Surface Current Radar\nOU\nUniversity of Oklahoma\nPACDEX\nPacific Dust Experiment\nPacTOP\nPacific Tsunami Observation Program\nPAH\npolycyclic aromatic hydrocarbon\n225","PAM\nportable automated mesonetwork\nPAN\nperoxyacetyl nitrate\nPBL\nplanetary boundary layer\nPCB\npolychlorinated biphenyl\nPCR\npolymerase chain reaction\nPDMS\npolydimethylsiloxane\nPDS\nPOSIX Data System\nPEGGY\n[platform; not an acronym]\nPEM-West\n[Western Pacific tropospheric chemistry experiment; not an acronym]\nPEN\nPassage Exchange Network\nPFRR\nPoker Flat Rocket Range\nPIREPS\npilot reports\nPMEL\nPacific Marine Environmental Laboratory (ERL)\nPOSIX\nPortable Operating System Interface for Computer Environments\nPPPL\nPrinceton Plasma Physics Laboratory\nPRE-STORM\nPreliminary Regional Experiment for STORM\nPREVENT\nPacific NW Regional Visibility Experiment using Natural Tracers\nPROBE\nPilot Radiation Observation Experiment\nPROGNOZ\n[Russian satellite]\nPSI\nPacific Sulfur/Stratus Investigation\nPSU\nPennsylvania State University\nQBO\nquasi-biennial oscillation\nRADM\nRegional Acid Deposition Model\nRAMM\nRegional and Mesoscale Meteorology (NESDIS branch)\nRASS\nRadio Acoustic Sounding System\nRELMAP\nRegional Lagrangian Model of Air Pollution\nRIDGE\nRidge Inter-Disciplinary Global Experiments\nRISC\nReduced Instruction Set Computer [workstation]\nRITS\nRadiatively Important Trace Species [program]\nRNN\nRegional NOCN Node\nROM\nRegional Oxidant Model\nROSE\nRural Oxidants in the Southern Environment\nROV\nremotely operated vehicle\nRPM\nRegional Particulate Model\nRR\nRisk Reduction (FSL branch)\nRSMAS\nRosenstiel School of Marine and Atmospheric Science\nRUC\nRapid Update Cycle\nSABRE\nSouth Atlantic Bight Recruitment Experiment\nSAFER\nSpectral Application of Finite Element Representation\nSAGE\nStratospheric Aerosol and Gas Experiment\nSAGA\nSoviet-American Gas and Aerosol [experiment]\nSANA\nSanierung der Atmosphare (Germany)\nSAR\nSynthetic Aperture Radar\n226","Acronyms and Initialisms\nSatellite Communications\nSATCOM\nstate-of-the-atmosphere variable\nSAV\nSolar Backscatter Ultraviolet [satellite]\nSBUV\nSystem Development Division (FSL)\nSDD\nShipboard Environmental Acquisition System\nSEAS\nSea Wide Field Sensor\nSeaWiFS\nSoutheast Fisheries Center (NMFS)\nSEFC\nSoutheast Florida and Caribbean Recruitment\nSEFCAR\nSpace Environment Laboratory (ERL)\nSEL\nSEL Data Acquisition and Display System\nSELDADS\nSEL Retrieval and Analysis of Scientific data system\nSELRAS\nSEL Space Image Sensor\nSELSIS\nSpace Environment Monitor\nSEM\nSolar Electronic Observatory Network (USAF)\nSEON\nsolar energetic particle\nSEP\nSpace Environment Services Center (SEL)\nSESC\nSpace Forecast Center (USAF)\nSFC\nStepped Frequency Microwave Radiometer\nSFMR\nSoftware Help in Applications, Research and Education [WMO Programme]\nSHARE\nSnow and Ice Distributed Active Archive Center\nSI.DAAC\nSeasonal Ice Monitoring and Modeling [Canadian program]\nSIMM\nSpace Influences on the Terrestrial Environment (SEL branch)\nSITE\n[GFDL GCM; not an acronym]\nSKYHI\nsupercooled liquid water\nSLW\nSolar Maximum Mission [satellite]\nSMM\nScanning Multichannel Microwave Radiometer\nSMMR\n[satellite; not an acronym]\nSOHO\nSolar Electromagnetic Radiation Study\nSOLERS\nSolar Connection to Transient Interplanetary Processes [program]\nSOLTIP\nSolar Observing Optical Network (USAF)\nSOON\nSouthern Oxidant Study\nSOS\nSouthern Ocean Waves Experiment\nSOWEX\nStratospheric Photochemistry, Aerosol, and Dynamics Expedition\nSPADE\nSpace Physics Analysis Network\nSPAN\nSpectral Radiation Experiment\nSPECTRE\nSemispectral Primitive Equation Model\nSPEM\nSpecial Projects Group (CMDL)\nSPG\nSPM\nsuspended particulate matter\nSSM/I Products Working Team\nSPWT\nScanning Radar Altimeter\nSRA\nSSBUV\nShuttle SBUV\nScientific Support Division (NSSL)\nSSD\nSpecial Sensor Microwave/Imager\nSSM/I\nSST\nsea-surface temperature\nSSTA\nSST anomaly\nSubtropical Atlantic Climate Studies\nSTACS\nStagnation Model Analysis Program\nSTAGMAP\nStratosphere-Troposphere Exchange Project\nSTEP\nStratospheric Ozone Intercomparison Campaign\nSTOIC\n227","STORM\nStormscale Operational and Research Meteorology\nSTORM-FEST\nSTORM Fronts Experiment Systems Test\nSTORMTIPE\nStorm Type Operational Research Model Test Including Predictability Evaluations\nSWAMP\nSouthwest Area Monsoon Project\nSWAN\n[finite difference code; not an acronym]\nSWIM\nSolar Wind Interplanetary Measurements\nSXI\nSolar X-ray Imager\nTAG\nTrans-Atlantic Geotraverse\nTAMEX\nTaiwan Area Mesoscale Experiment\nTAMU\nTexas A&M University\nTAO\nTropical Atmosphere Ocean [array]\nTDWR\nTerminal Doppler Weather Radar\nTIROS\nTelevision and Infrared Observation Satellite\nTIWE\nTropical Instability Wave Experiment\nTKE\nturbulent kinetic energy\nT-LAPS\nTerminal LAPS\nTM\nThematic Mapper\nTNIRO\n[Pacific Research Institute of Fisheries and Oceanography, Russia]\nTOGA\nTropical Ocean Global Atmosphere [project]\nTOMS\nTotal Ozone Mapping Spectrophotometer\nTOVS\nTIROS Operational Vertical Sounder\nTPPN\nTrans-Pacific Profiler Network\nTTO\nTransient Tracers in the Ocean [experiment]\nUAM V\n[urban-scale photochemical model]\nUARS\nUpper Atmospheric Research Satellite\nUCAR\nUniversity Corporation for Atmospheric Research\nUNOLS\nUniversity-National Oceanographic Laboratory System\nUSAF\nU.S. Air Force\nUSGS\nU.S. Geological Survey\nUV\nultraviolet\nUW\nUniversity of Wisconsin\nVAD\nVelocity-Azimuth Display\nVAFTAD\nVolcanic Ash Forecast Transport and Dispersion [model]\nVAS\nVISSR Atmospheric Sounder\nVDUC\nVAS Data Utilization Center\nVENTS\n[hydrothermal venting program; not an acronym]\nVICBAR\n[barotropic hurricane track prediction model; not an acronym]\nVISSR\nVisible and Infrared Spin-Scan Radiometer\nVMS\nVisual Memory Systems\nVNIRO\n[Russion Research Institute of Marine Fisheries and Oceanography]\nVOC\nvolatile organic compound\nvos\nVolunteer Observing Ship\n228","Acronyms and Initialisms\nWAP\nWeather Analysis and Prediction (FSL branch)\nWCRP\nWorld Climate Research Program\nWDC\nWorld Data Center\nWEPOCS\nWestern Equatorial Pacific Ocean Circulation Study\nWESTRAX\nWestern Tropical Atlantic Experiment\nWIND\n[spacecraft]\nWISE\nWeather Information and Skill Experiment\nWISP\nWinter Icing and Storms Project\nWMO\nWorld Meteorological Organization\nWOCE\nWorld Ocean Circulation Experiment\nWOTAN\nWeather Observations Through Ambient Noise\nWPDN\nWind Profiler Demonstration Network\nWPL\nWave Propagation Laboratory (ERL)\nWSR-88D\nWeather Surveillance Radar\nWWA\nWorld Warning Agency\nXBT\nexpendable bathythermograph\nXSEL\n[data transfer and display system; not an acronym]\n*U.S. GOVERNMENT PRINTING OFFICE: 1993-774-025/69042\n229"]}