{"Bibliographic":{"Title":"Environmental Research Laboratories Programs and Plans","Authors":"","Publication date":"1985","Publisher":""},"Administrative":{"Date created":"08-20-2023","Language":"English","Rights":"CC 0","Size":"0000735547"},"Pages":["QC\n807.5\nENVIRONMENTAL\n.E58\n1985/\nRESEARCH\n1986\nLABORATORIES\nPROGRAMS\nAND\nPLANS\n1\nFY 1985\nPROGRAMS\nAND\nFY1986\nPLANS\nLIBRARY\nAPR 2 9 1986\nN.O.A.A.\nU. S. Dept. of Commerce\nU.S. Department of Commerce\nNational Oceanic and Atmospheric Administration\nEnvironmental Research Laboratories","ENVIRONMENTAL\nRESEARCH\nLABORATORIES\nPROGRAMS\nAND\nPLANS\nFY1985\nPROGRAMS\nAND\nFY 1986\nPLANS\nQC\n807.5\nDECEMBER 1985\nE58\n1985/1986\nDEPARTMENT COMMUNITY\nOF\n*\nAvenue\nSTATES\nOF\nU.S. Department of Commerce\nNational Oceanic and Atmospheric Administration\nEnvironmental Research Laboratories\nBoulder, Colorado\nVernon E. Derr, Director","NOTICE\nMention of a commercial company or product does not constitute an endorsement\nby NOAA Environmental Research Laboratories. Use for publicity or advertising\npurposes of information from this publication concerning proprietary products or\nthe tests of such products is not authorized.\nDocument available in Programs Office, Environmental Research Laboratories, Boulder, Colorado","Environmental Research Laboratories\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nESG\nSTORM\nTOGA\nCRP\nWRP PROFS WMP\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nWPL\nARL\nAL\nSEL\nThe mission of the Environmental Research Laboratories (ERL) is to conduct an integrated\nprogram of fundamental research, related technology development, and services to im-\nprove understanding and prediction of the geophysical environment comprising the oceans\nand inland waters, the lower and upper atmosphere, the space environment, and the Earth.\nCONTENTS\nPage\nIntroduction and Summary of ERL Research\n1\nOffice of the Director\n17\nOD\n19\nEnvironmental Sciences Group\nESG\n19\nClimate Research Program\nCRP\n24\nWeather Research Program\nWRP\n30\nProgram for Regional Observing and Forecasting Services\nPROFS\n42\nWeather Modification Program\nWMP\n51\nAtlantic Oceanographic and Meteorological Laboratory\nAOML\n73\nPacific Marine Environmental Laboratory\nPMEL\n95\nGreat Lakes Environmental Research Laboratory\nGLERL\n113\nGeophysical Fluid Dynamics Laboratory\nGFDL\n123\nNational Severe Storms Laboratory\nNSSL\n145\nWave Propagation Laboratory\nWPL\n159\nARL\nAir Resources Laboratory\n193\nAeronomy Laboratory\nAL\n219\nSEL\nSpace Environment Laboratory\n235\nCooperative Institutes\n235\nCooperative Institute for Marine and Atmospheric Studies\nCIMAS\n243\nCooperative Institute for Mesoscale Meteorological Studies\nCIMMS\n245\nCooperative Institute for Research in the Atmosphere\nCIRA\n246\nCooperative Institute for Research in Environmental Sciences\nCIRES\n257\nJoint Institute for Marine and Atmospheric Research\nJIMAR\n260\nJoint Institute for Study of the Atmosphere and Ocean\nJISAO\n263\nNational STORM Program Office\nSTORM\n265\nInternational TOGA Project Office\nTOGA\n269\nAppendix: Acronyms and Initialisms\niii","These are highlights of Laboratory accomplishments and\nabbreviated summaries of immediate objectives. More\ncomprehensive and detailed descriptions of activities,\nresults, and plans may be found in the Laboratories'\nannual reports (which may be obtained directly from\nthe Laboratories) and in the open literature. Inter-\nested readers are referred to the annual Environmental\nResearch Laboratories Publication Abstracts.","ENVIRONMENTAL\nRESEARCH\nLABORATORIES\nThe Environmental Research Laboratories (ERL) are organized within NOAA's\nOffice of Oceanic and Atmospheric Research and have their headquarters in\nBoulder, Colo. They include major units located throughout the United States:\nBoulder, Colo.\nAeronomy Laboratory\nAtlantic Oceanographic and Meteorological Laboratory\nMiami, Fla.\nSilver Spring, Md.\nAir Resources Laboratory\nBoulder, Colo.\nEnvironmental Sciences Group\nPrinceton, N.J.\nGeophysical Fluid Dynamics Laboratory\nGreat Lakes Environmental Research Laboratory\nAnn Arbor, Mich.\nNorman, Okla.\nNational Severe Storms Laboratory\nSeattle, Wash.\nPacific Marine Environmental Laboratory\nBoulder, Colo.\nSpace Environment Laboratory\nBoulder, Colo.\nWave Propagation Laboratory\nIn addition, institutes administered jointly by ERL and universities undertake\nresearch for ERL. ERL also sponsors research through contracts and grants to\nuniversities, State and Federal agencies, and private enterprise. Many ERL\nresearch efforts rely on the cooperation of other NOAA elements, including\nNESDIS, NOS, NMFS, and the Office of Aircraft Operations.\nERL's program includes fundamental research to develop technology and\nimprove NOAA services to the public. Samples of outputs are Doppler radar\ntechnology (to improve tornado detection and warnings), mathematical models\n(to predict climate and ocean variations), ocean current forecasts (to mini-\nmize ship operation costs), observations of ocean upwelling (to maximize fish\ncatches), and solar activity forecasts (to protect, for example, radio communi-\ncations).\nUsers of ERL outputs include the atmospheric, marine, and space research\ncommunities, NOAA service components (National Weather Service, National Ocean\nService, National Environmental Satellite, Data, and Information Service),\nFederal, State, and local governments, and the private sector.\nThe ERL program is broad, embracing studies relating to the oceans and\nGreat Lakes, the lower and upper atmosphere, and the solar-terrestrial environ-\nment. Studies and activities focus in five subject areas:\nWeather observation and prediction\nClimate and air quality\nOcean and Great Lakes prediction\nMarine resources\nSolar-terrestrial research and services","The following summary of ERL research is organized in terms of subject\nareas. Succeeding sections discuss the accomplishments and plans of the indi-\nvidual Laboratories and other units. The Appendix lists acronyms and initial-\nisms used in those sections.\nWEATHER OBSERVATION AND PREDICTION\nWeather Observation and Prediction includes programs of AL, AOML, GFDL,\nNSSL, ESG (WRP, PROFS, WMP), WPL, and the joint institutes. These programs\ninteract directly with Ocean and Great Lakes Prediction R&D and with Solar\nTerrestrial Research and Services programs dealing with the lower and upper\nphysical boundaries of the atmosphere, with Air Quality programs relating to\nthe short term, and with Climate programs relating to the long term. Weather\nprograms include research on observational systems, modeling and prediction,\nsevere storms, hurricanes, sea-air interaction, cloud and precipitation pro-\ncesses, mesoscale meteorology, synoptic weather, and transfer of technology.\nObservational Systems\nThe Boulder Atmospheric Observatory includes a 300-m-high meteorological\ntower and associated remote sensors. The atmospheric research conducted at\nthis facility includes micrometeorological and boundary layer studies, and\nmeso-beta-scale (i.e., scales up to 200 km) research. The latter research\nincludes downslope wind situations and studies of clouds and precipitation\nunder upslope conditions. Smaller scale research concerns low-level winds and\nwind shear, of importance to aircraft operations.\nThe most versatile and successful observational tools are radar and\nlidar. Techniques being developed using radar remote sensing include optical\nand infrared scintillation for measurement of wind (path-averaged values),\nrefractivity fluctuations, heat and moisture flux, rainfall rate, and drop-\nsize distribution. Doppler radar research continues on flow and precipitation\nfields within severe thunderstorms in support of the interagency NEXRAD Pro-\ngram whose goal is to produce a national Doppler radar network in the late\n1980's Also in development are optical and infrared lidar techniques for the\nremote measurement of winds, temperature, humidity, and aerosols; passive\nmicrowave techniques for the measurement of temperature and humidity profiles\nand cloud liquid; and active radar techniques for the measurement of winds,\nclouds, precipitation, turbulence, and refractivity fluctuations. As tech-\nniques are developed, they are transferred to operational NOAA programs.\nA high-power, large-antenna VHF Doppler radar technique for measuring\nwinds, turbulence, and gravity waves in clear air is being used at Poker Flat,\nAlaska, to gather important research data in the lowest 100 km of the atmos-\nphere. Radar systems at Platteville, Colo., and Stapleton International Air-\nport, Denver, and three other sites in Colorado are used for real-time wind-\nspeed and wind direction data, and are research prototypes for the Profiler\nsystem being developed, to enhance radiosonde wind-profiling capability.\nMicrowave radiometer devices for vertical sensing of water vapor and liquid\nwater are also part of this Colorado network and are research prototypes for\n2","the Profiler system, also to enhance the radiosonde temperature and humidity\nprofiling capability.\nRemote techniques are being developed to map electrical discharges in\nthree-dimensional space, for correlation with storm dynamics and precipitation\nand with changes in electric fields.\nModeling and Prediction\nModeling and prediction efforts in ERL have several goals. In the large\nscale, goals include the following: to develop or improve atmospheric predic-\ntion models in the 5- to 30-day time frame (for application by the National\nWeather Service), to identify external forcing mechanisms that models must\ninclude to simulate the evolution of macroscale atmospheric disturbances over\nthe range of several weeks to 4 months, and to search for a physically based,\nprobabilistic approach for long-range simulation of atmospheric variations.\nIn the mesoscale, goals include understanding of hurricane dynamics, including\nthe study of small-scale features within hurricane systems; and production of\naccurate numerical simulations of mesoscale processes, to understand the role\nof synoptic-scale parameters in severe-storm generation and evolution.\nSevere Storms\nSevere-storm researchers acquire data with specially developed instru-\nments, and analyze these and conventionally acquired data to obtain a more\ncomprehensive understanding of severe storms, to develop models of convective\nstorms, to compare models with observations, and ultimately to improve predic-\ntion of severe storms.\nInstrumentation developed in ERL for this research includes surface net-\nworks, an instrumented television tower, two large 10-cm Doppler radars, an\natmospheric electricity measurement system, two 3-cm transportable Doppler\nradars to measure three-dimensional velocity fields in convective storms, and\npressure sensor arrays to detect and monitor gust fronts in the vicinity of\nairports.\nHurricanes\nHurricane research involves three major activities: (1) Hurricane field\nresearch assembles the descriptive data needed to support analytical and theo-\nretical studies to improve the understanding of hurricane structure and behav-\nior. The ultimate purpose is to improve operational NWS prediction of hurri-\ncanes. The field program makes use of air- and ground-based radar, aircraft,\nand satellite observations. Uniquely well-equipped NOAA aircraft fly for ap-\nproximately 200 hours per year. Investigations include boundary layer proc-\nesses, evolution of convection and associated wind fields, hurricane motion\nand internal dynamics, cloud microphysics, and flow characteristics in and\nnear the eyewall and spiral rainbands. (2) Hurricane modeling activities seek\nto develop and improve models for hurricane track prediction, mesoscale dynam-\nics, and statistical track forecasting. (3) Hurricane prediction research\ninvolves a combination of efforts on pre-hurricane disturbances, hurricane\n3","genesis and development, hurricane climatology, general tropical meteorology,\nradar precipitation measurement, analysis of Seasat satellite data, and hurri-\ncane sea-air exchange processes.\nSea-Air Interaction\nSea-air interaction research involves the experimental study and numeri-\ncal modeling of sea-air interactions, especially under extreme weather condi-\ntions such as hurricanes. The experimental studies use a series of aircraft\nobservations of sea-air (or lake-air) interactions, such as surface wind and\nwave fields under a wide range of meteorological and coastal conditions.\nThese observations are compared with model predictions of waves and storm\nsurges, to test hypotheses and understandings, and to validate or improve the\nmodels.\nCloud and Precipitation Processes\nResearch on cloud and precipitation processes involves numerical modeling\nof convective clouds to predict precipitation and phenomena such as downbursts\nthat are hazards to aviation. To support these experiments, optical, infra-\nred, and microwave radar and lidar systems are used to measure cloud-echo in-\ntensities at three optical and three radio frequencies as a function of three-\ndimensional space and time. These echo-intensity fields can be measured as a\nfunction of both wavelength and polarization. The Doppler effect is used at\nradio and optical frequencies to determine velocity fields and turbulent kinet-\nic energy dissipation rates. The multifrequency approach provides information\non droplet size, and the dual polarization capabilities permit identification\nof the cloud or precipitation particles as spherical water droplets or non-\nspherical ice crystals. Microwave radiometric techniques are used to measure\nline integrals of cloud liquid water and water vapor.\nCloud Physics Research and Technology Development\nNOAA conducts cloud physics research on hurricanes and related convective\ncloud systems, and the acidity of precipitation. In field programs, research\naircraft penetrate hurricane circulations to gather data on structural charac-\nteristics, ranging from cloud microphysical to digital radar data. The obser-\nvational efforts contribute to the development of numerical models of hurri-\ncanes.\nA Federal-State Cooperative Program is developing criteria for the effec-\ntive evaluation of operational cloud seeding. The research and development\nneeded to establish these criteria are carried out through contracts to four\nStates under a Congressional mandate. NOAA manages the contracts and coordi-\nnates the research.\nThe program provides cost-effective research opportunities to develop\ntechnologies that address goals in agriculture, energy, and water resources.\nCurrent activities include studies on midwestern summer rainfall enhancement\nfor corn and soybean production, by Illinois; the importance of western seed-\ning programs to water supplies in downwind acid-rain regions, by Nevada; the\n4","physics of hailstorms and the enhancement of rain over the Great Plains, by\nNorth Dakota; and the enhancement of intermountain snowfall for irrigation and\nenergy uses, by Utah.\nMesoscale Processes\nMesoscale research includes the study of atmospheric processes, with par-\nticular emphasis on meso-alpha-scale convective systems. This includes work\nto improve the understanding of excessive convective rainfall and to develop\ntechniques for forecasting flash-flood-producing storms. Other activities are\ndevelopment of mesoscale numerical models, conduct of theoretical and diagnos-\ntic studies, analyses of mesoscale weather systems, participation in meteoro-\nlogical field experiments, and studies of the microstructure and turbulence of\nthe atmospheric boundary layer using airborne and remote-sensing measurement\ntechniques.\nTechnology Transfer\nERL develops and tests operational sensing systems that are transferred\nto service components of NOAA such as NWS, and to other Federal agencies such\nas the Federal Aviation Administration (FAA). Doppler radar for identifica\ntion and warning of severe thunderstorms and tornadoes has been tested for the\nAir Force and the FAA. These tests indicate that Doppler radar can reliably\ndetect destructive tornadoes many minutes before they produce damage.\nERL, NWS, and NESDIS cooperate to improve local weather information ser-\nvice systems for NWS. System designs incorporate many advances of the past\ndecade in satellite- and ground-based remote sensing, in automated and surface\nweather stations, in data processing and display, in mesoscale analysis and\nforecasting, and in dissemination of data and forecasts.\nCLIMATE RESEARCH\nClimate Research includes programs involving eight Laboratories and four\njoint institutes. Climate programs interact directly with other major pro-\ngrams such as Air Quality, Solar-Terrestrial Research and Services, and Ocean\nand Great Lakes Predictions, and on shorter time scales, with Weather Observa-\ntion and Prediction. Climate programs include ocean-atmosphere studies; obser-\nvation and analysis of solar, atmospheric, and stratospheric variability; and\nclimate modeling.\nOcean-Atmosphere Studies\nA major ocean-atmosphere program, Equatorial Pacific Ocean Climate Stud-\nies (EPOCS), is investigating the physics and dynamics of the coupled ocean-\natmosphere system in the equatorial Pacific as part of the international Tropi-\ncal Oceans and Global Atmosphere (TOGA) program. Understanding this system is\nvital to comprehending global fluctuations of climate on interannual time\nscales. A broad spectrum of oceanographic and atmospheric parameters is being\n5","monitored by a variety of sensors to create an integrated data base. Satel-\nlites are continuously monitoring winds and sea surface temperatures. Re-\nsearch vessels are using XBT's and current profilers to determine vertical\nthermal and dynamic cross sections. Moored arrays at or near the Equator are\nused to determine the major time scales of variability of ocean parameters\nsuch as current, temperature, and salinity. Drifting buoys are used in the\nPacific equatorial current system to determine the larger scale current pat-\nterns as well as other spatially distributed parameters. Other projects are\nusing aircraft to measure vertical fluxes of heat, moisture, and momentum over\nthe tropical Pacific.\nAnother major program, Subtropical Atlantic Climate Studies (STACS),\nseeks to identify the processes that contribute most to the poleward transport\nof heat in the North Atlantic Ocean and to develop the technology to monitor\nthese processes operationally. The initial emphasis of STACS has been on de-\nveloping techniques to monitor the mass transport and heat content of the\nFlorida Current. Several techniques are being tested to determine the most\nefficient approach for long-term monitoring of the Florida Current. Among\nthese are measurement of electromagnetic induction from communications cables,\nand use of coastal tidal stations.\nIn addition to EPOCS and STACS, a broad range of research is conducted on\nthe temporal and spatial variability of water mass structure, sea level, cur\nrents, and general circulation of deep ocean and coastal waters. Vertical\nmixing processes in the upper ocean, wind-generated response of middle-lat-\nitude upper ocean currents and temperature fields, and methods of inferring\nsurface wind stress fields from satellite data are specific concerns.\nIn a technology development project, the potential of using low-frequency\nsound sources and detectors (acoustic tomography) to measure the structure of\nthe ocean is being investigated.\nClimate Variability\nProjects relating to climate variability include airborne measurement of\nsolar radiation over the equatorial Pacific; recently completed construction\nof a global data set describing climate variations over the past 150 years;\ndetermination of the intensity and time scales of variations in the solar\nultraviolet radiation as a function of wavelength in the 110- to 400-nm range;\nand determination of the significance of such variations in molecular dissocia-\ntion atmospheric chemistry, upper atmosphere heating, and measurements of at-\nmospheric constituents. Global levels of atmospheric trace constituents that\nhave significant effect on the Earth's radiation budget, including carbon\ndioxide, ozone, aerosols, and water vapor, are monitored and analyzed. Four\nmonitoring stations (Alaska, Hawaii, Samoa, and South Pole)--one tropical and\none high-latitude in each hemispheres0.75-inch diameter, winds 50 kn,\ntornadoes FO severity, rainfall 1.0 inch in 30 min); and catastrophic (hail\n2.0 inches diameter, winds 75 knots, tornadoes >F1 severity, major flooding\ncausing considerable loss of life and damage to property). Very-short-term\nforecasts (up to 2 h) were termed alerts; they were issued only for signifi-\ncant and severe weather, with mandatory lead time of at least 30 min. The\nshort-term forecasts were issued for a 51/2-h period and were termed convective\noutlooks; they were issued for significant and severe thunderstorms (hail,\nwind, rainfall) and for tornadoes. All these nowcasts, alerts, and convective\noutlooks were assigned probabilities rather than being presented simply as\ncategorical forecasts. In addition to these convective storm forecasts,\nregularly scheduled probability-of-precipitation forecasts were prepared every\n2 h by isoplething forecast probabilities over the forecast area for two\nsuccessive 1-h periods.\n41","A series of computer algorithms available throughout the exercise also\nprovided guidance, particularly for the nowcasts. One set of algorithms,\ncalled the NEXRAD algorithms, provided guidance on hail detection, mesocyclone\ndetection, and storm-tracking. Another algorithm (ZDR) provided output distin-\nguishing between rain and hail on the basis of backscatter return from verti-\ncally and horizontally polarized radar pulses.\nVerification data for convective storms were obtained by vectoring radio-\ncontrolled chase cars over the forecast area, using a 1-mile-interval gridded\nmap system. The set of visual observations obtained throughout the area\nduring the experiment was nearly perfect.\nA wide variety of image and graphics products was available for four dif-\nferent scales of motion ranging from the North American continent down to a\nlocal forecast area of 150 km radius centered near Boulder. In addition to\nthe regularly scheduled products, the forecasters could call a large set of\nprograms into play to perform diagnostic operations such as time series param-\neters, moisture convergence zones, and cloud-top temperatures deduced from\ninfrared satellite images. Wind profiler data were also available for heights\nup to 12 or 14 km at four sites throughout the exercise, updated hourly.\nIn summary, the exercise included many new forecast procedures, a wealth\nof new data (images, graphs, and applications programs) and an excellent set\nof verification data for subsequent analyses. The analyses of the RT85 re-\nsults are now being evaluated by the T&E staff as the major task for the\ncoming year.\nPlans FY 1986\nEvaluate RT85 nowcasts, alerts, and convective outlooks using scoring\ntechniques based on contingency tables, Brier scores, and Signal\nDetection Theory.\nDevelop Radar Data Processor (RADAP) hail detection algorithms modified\nfor Colorado high plains thunderstorms.\nEvaluate the various hail detection algorithms (NEXRAD, RADAP, and ZDR)\nas forecast guidance tools.\nParticipate in a cool-season forecast exercise scheduled for the\n1985/1986 winter period.\nWEATHER MODIFICATION PROGRAM\nDuring a decade when the limitations to the nation's fresh water sup-\nplies are increasingly being realized, the NOAA Weather Modification Program\n(WMP) is taking a hard scientific look at cloud evolution and water budgets,\nand the realities of cloud-seeding technologies for enhancing precipitation.\nResearch in this program is focused on six avenues that promise breakthroughs\n42","in monitoring, forecasting, modifying, and understanding the effects of cloud\nsystems on the meso-beta to meso-gamma scales:\nTesting and application of cloud remote sensors.\nIn-cloud tracer technologies.\nChemical/physical technologies to evaluate precipitation processes.\nIce nucleant chemical kinetics.\nModeling of cloud processes and their links to the mesoscale.\nPrecipitation impacts on hydrology and agriculture.\nThe Weather Modification Program (WMP) office oversees the Federal-State\nCooperative Program in Weather Modification Research, which began in 1979. At\nthat time the U.S. Congress appropriated funds for a cooperative, scientific\nevaluation of certain ongoing operational cloud-seeding programs. Such\nFederal-State cooperative programs were among the many recommendations made to\nthe Secretary of Commerce and the President in 1978 by an independent Weather\nModification Advisory Board appointed in response to the passage of Public Law\n94-490, which required that the Secretary of Commerce develop a plan at the\nFederal level whereby weather modification research activities could be coordi-\nnated. The Board resolved that \"locally controlled operational projects of\nfer an excellent opportunity for increasing scientific knowledge and technol-\nProper design, well-conducted operations, and careful data\nogy development\ncollection will permit useful evaluation of the effectiveness of selected\nmulti-year operational projects. The resulting scientific gains will be siz-\nable, and most local users, sooner or later, will appreciate Federally-spon-\nsored scientific evaluation of the operational projects locally supported. \"\nThis resolution serves as a charter for the NOAA Program.\nIn 1979, NOAA contracted with Colorado State University to develop a\ndesign for the conduct of the first two programs approved, those for North\nDakota and Utah; various advisory groups provided recommendations for the con-\nWMP\nduct of field research programs in these two states. In FY 1983, Nevada was\nadded to the program. In FY 1984, Illinois was added.\nCurrently, research in the four states is supported through cooperative\nagreements with the NOAA WMP. The mission of WMP is to support, conduct, and\ncoordinate basic and applied research to understand cloud and precipitation\nprocesses and their role in the hydrologic cycle under natural influences, and\nwith inadvertent and purposeful modification.\nThe summer and winter seasons and four different climate regimes are rep-\nresented by the four state programs. Illinois is concerned with summer convec-\ntive rain processes as they directly affect crop production in the humid, temp-\nerate climate of the Midwest cornbelt. Summer convective precipitation and\nhail in the sub-humid, rainfall deficient, wheat-growing regime of the north-\nern Great Plains are the concern of North Dakota. Utah is addressing winter\norographic snowfall and its impact on summer runoff and irrigated agriculture\nin the arid to semi-arid climate of the Great Basin, which is precipitation\ndeficient in all seasons. Initial cloud-seeding activities in Nevada were\n43","stimulated by requests from Native Americans who were concerned about the\namount of water reaching their reservations. To assure water supplies for\nirrigated agriculture and urban uses, Nevada must address winter precipitation\non both the windward and lee sides of the Sierra Nevada where there occurs a\ndramatic transition from generally abundant but annually highly variable snow-\nfall in a sub-humid climate to deficient snowfall in a semi-arid, steppe\nclimate.\nThus each program is of regional interest, and collectively the programs\nare of national interest in that they address one of a very few technologies\npotentially available for increasing water supplies to alleviate deficit spend-\ning of the nation's fresh water. All four programs include sizable State\ninvestments.\nThe long-range goals of the four cooperative programs are as follows:\nUtah/NOAA: Understand the water budgets and potential for snowfall\nenhancement in winter orographic clouds within the Great Basin, and\nphysically and statistically estimate the actual effects of operational\nseeding.\nNevada/NOAA: Determine the effect of winter orographic cloud seeding\nin California on snowfall enhancement potential and water supplies in\nareas of Nevada downwind of the seeded target areas.\nIllinois/NOAA: Understand the feasibility of summer rainfall\nenhancement in the Midwest and the agricultural effects of added\nrainfall during periods of water and heat stress as well as those of\nexcessive rainfall.\nNorth Dakota/NOAA: Determine the potential and actual effectiveness of\nseeding summer convective clouds of the northern Great Plains to\nenhance growing-season rainfall, and determine the feasibility of hail\nsuppression.\nAccomplishments FY 1985\nCOOPERATIVE RESEARCH-ILLINOIS/NOAA\nThe Illinois State Water Survey obtained NOAA funding and formally\nentered the Federal-Stat Cooperative Research Program in April 1984. Work in\nearlier years, in part through other NOAA support, established the Precipita-\ntion Augmentation for Crops Experiment (PACE), which is continuing with these\nspecific objectives:\nDetermine in a scientific manner the precipitation alterations that are\nobtainable.\nDetermine the effects of these alterations on all aspects of\nagriculture.\n44","Determine the societal and environmental desirability of these\nalterations.\nTop priority FY-1985 activities and corresponding accomplishments were\nthe following:\n(1) Studies of cloud and precipitation elements and systems.\nResearch was initiated with radar echo data, to define experimental\nunits, as needed in the exploratory phase of PACE.\nSatellite interpretation of precipitation systems was started.\n(2) Studies of economic and environmental impacts of summer rain changes.\nProgress included installation of soil moisture tubes at four sites,\nacquisition of a neutron probe, and initiation of routine\nmeasurements of soil moisture at these sites for studies of soil\ninfiltration of rainfall.\nA three-phase research effort began, to assess the agricultural economic\nimpacts of precipitation in recent wet and very dry summers and under\npresent farm practices.\n(3) Development of facilities for PACE field operations and evaluations.\nEngineering to add computer and Doppler capabilities to a 10-cm radar was\ninitiated under a special appropriation for instrumentation.\n(4) Review, interpretation, and summarizing of all relevant past research\nin the Midwest.\nResults for developing scientific hypothesis and evaluation methodologies\nwere integrated.\nAn assessment of all past weather modification research in the Midwest,\nWMP\nincluding an annotated bibliography of all relevant documents, was\ncompleted for use in hypothesis development.\nCOOPERATIVE RESEARCH-NEVADA/NOAA\nThis program is oriented to study the microphysical and dynamical aspects\nof the problem of \"area of effect\" in a region of the Central Sierra Nevada\nwhere operational and research seeding programs are being conducted in\nCalifornia, producing a potential for downwind effects in Nevada.\nThe work is and will continue to be focused on (1) transport, dispersion,\nand capture of seeding agents; (2) stable isotopes, and ice crystal growth and\nfallout in relation to liquid water locations in mesoscale systems; and (3)\nthe distribution of liquid water and ice in Sierra Nevada winter storms.\nThe utility of new wet-weather tracer technology is being experimentally\ndemonstrated. The oxygen isotope ratio in snow (180/160), which is estab-\n45","lished when water substance freezes in a cloud, is providing a means to esti-\nmate where in a cloud and by what growth processes (vapor deposition or accre-\ntion) snow crystals gather their mass. Silver sampling in snow is demonstra-\nting the confinement of ground-released particles (AgI) and is showing what\nportions of cloud volumes are reached by particle plumes in clouds over com-\nplex terrain. The use of two compositions of particles with similar size and\nmass distributions, one active and one inactive, as ice nucleants, is being\ndeveloped to distinguish between cloud nucleation and scavenging processes; a\nsecond season of field testing added data points that actually show this dif-\nference and began to confirm (1) the validity of the dual-tracer hypothesis\nand (2) the participation of the ice nucleant in the precipitation-forming\nprocess.\nThe implications with respect to effective delivery of cloud seeding\nmaterial (or, e.g., to the dispersion of powerplant effluents) into cloud\nsystems are profound. All these technologies have broad application in basic\ncloud studies, weather modification, and air quality.\nUnder a special grant for instrumentation, Nevada is building a dual-wave-\nlength radiometer for continuous monitoring of atmospheric water vapor and\ncloud liquid water.\nCOOPERATIVE RESEARCH-NORTH DAKOTA/NOAA\nIn FY 1984, a preliminary field study of sulphur hexafluoride (SF6) as an\nin-cloud tracer of plume transport and diffusion was successfully conducted.\nThe pioneering results indicated that circulation within rigorously growing\nconvective clouds was very confined; continuous cloud base seeding generated\nplumes of only relatively small diameters (e.g., 100 to 500 m) at a few thou-\nsand feet above the seeding altitude. The SF6 plumes were found to spread\nmore uniformly through the cloud volumes only at cell top, or in dissipating\nturrets.\nThese characteristics of cloud transport were examined again in an FY-\n1985 June-July field experiment. A new airborne SF6 sampler developed\nby\nWashington State University (WSU) was field tested, and its samples were com-\npared with the different SF samples obtained in the previous season. The\ninstrument was carried by the University of North Dakota Cessna Citation jet\naircraft, which offered pin-point navigation and also carried a full comple-\nment of cloud physics samplers. The WSU SF6 sampler was found to have a much\nbetter threshold of detectability and response time than earlier samplers had.\nAdditional cumuli were treated and sampled, and calculations of averages are\nunder way. The tracer studies represent landmark research in cloud transport;\nthis knowledge is crucial to the fields of weather modification and air\nquality.\nAdditional radar studies were also conducted to relate cloud echo height\nvolume to rain volume. A narrow-beam radar provided by the Bureau of Reclama-\ntion improved the resolution of the measurements.\nFast-acting ice crystal nucleants developed for North Dakota in the\nColorado State University Atmospheric Simulation Laboratory were field tested.\nGeneration modification is needed for efficient burning, but use of ice\n46","crystals as nuclei is potentially a major breakthrough for timing treatment\nand precipitation growth in rapidly evolving cumulus clouds.\nCOOPERATIVE RESEARCH-UTAH/NOAA\nThe three major research challenges to the Utah/NOAA program are (1) to\ndetermine the spatial and temporal distribution and evolution of supercooled\ncloud water, (2) to evaluate the effectiveness of delivery of seeding mate-\nrials, and (3) to determine the trajectories of natural and seeded cloud and\nprecipitation particles.\nA strong approach to these key problems was established by assembling an\nimpressive network of instrumentation including both in-situ and remote sen-\nsors. The 1981 and 1983 field studies were, with some variations, supported\nby X-, K-, and CHband radars, a scanning dual-channel radiometer, a polariza-\ntion lidar, rawinsondes, a mountaintop supercooled-liquid-water detector, a\nnetwork of precipitation gauges, and a cloud physics aircraft.\nIn a very successful experiment in January and February of 1985, studies\nof windflow and cloud processes were emphasized, using, simultaneously, a dual-\nwavelength radiometer to measure liquid water content, a K-band radar to\ndetect the conversion of liquid water to ice crystals and measure cloud top\nheight, a polarized lidar to follow cloud base height and phase of water, a\nC-band (5 cm) Doppler radar to determine low-level wind fields up and along\nthe barrier, constant-level balloons and SF6 released to track airflow and\nplumes, and supporting soundings, riming sensors, and precipitation gauges.\nThese physical measurements provided a strong basis for evaluating the\ncloud water budget and will contribute substantially to the refinement of the\noperational technology and total assessment of the snowpack enhancement pro-\ngram. Intensive analyses are in progress by participants from the Desert Re-\nsearch Institute, University of Utah, Colorado State University, Atmospherics,\nInc., and North American Weather Consultants.\nWMP\nPlans FY 1986\nCOOPERATIVE RESEARCH-ILLINOIS/NOAA\nFY 1986 will be the second full year of Illinois participation in the\nprogram. Analyses of radar echo evolution, based on data previously acquired,\nwill be completed. Satellite cloud studies will be integrated with the radar\nstudies to identify cloud/echo types most likely to be suitable for increased\nprecipitation efficiency, and thus for further cloud physics studies by remote\nsensing and aircraft. The Illinois State Water Survey will complete modifica-\ntion of its HOT (Hydrometeorological Operational Tool) 10-cm radar to include\na Doppler capability, which, with its existing CHILL (CHicago and ILLinois)\n10-cm radar (a national facility), will provide a dual-Doppler capability.\nReview of past Water Survey tracer work in convective clouds will be com-\npleted, as will review of the physics of all previous weather modification\nefforts relevant to Illinois. Use of soil moisture measurements and economic\nmodels will be continued, to assess major effects of real or hypothetical pre-\n47","cipitation variations on agriculture production capacity and water quality.\nNew field studies of summer convective clouds in Illinois will be initiated.\nCOOPERATIVE RESEARCH-NEVADA/NOAA\nA field program during the winter and spring of 1986 will assist in (1)\ndevelopment of tracer technologies and studies of the spatial and temporal\ndispersion of seeding aerosols; (2) studies of the temperature range over\nwhich the water has frozen to form the ice crystals and snowflakes reaching\nthe surface in the project area; (3) assessment of nucleation, scavenging, and\nprecipitation processes using chemical and isotope techniques; (4) determina-\ntion of the precipitation, supercooled liquid water, and ice across the Sierra\nNevada crest, using a surface network that includes radars and a microwave\nradiometer; and (5) determination of the chemical makeup of the snow falling\ndownwind of the Sierra Nevada crest. Development and construction of a dual-\nwavelength radiometer for shared use in the Federal-State program will be com-\npleted, and field tests will also be completed.\nCOOPERATIVE RESEARCH-NORTH DAKOTA/NOAA\nFollowing are the principal activities for FY 1986:\nContinued analyses of the pioneering 1984 and 1985 preliminary tracer\nstudies of cloud transport and correlated cloud physics to determine\nplume and treatment characteristics over time and space.\nLaboratory tests to improve reliability and efficiency of cloud seeding\ngenerators that produce the new fast-acting ice crystal nucleants, such\nas the chemical complex AgI.AgCl.NaCl.\nContinuation of a comparative exploratory field experiment on in-cloud\ndiffusion and treatment signatures for relatively fasta and slow-\nreacting AgI chemical complexes, and another slow complex.\nContinued 2-D modeling of the theorized North Dakota precipitation\nprocess.\nFurther analyses of radar data to complement the existing climatology of\ncloud echo volumes vs. rainfall, to determine the time between first and\nmaximum echo heights for treated and untreated cells, and initial field\nstudies to attempt to relate cloud transport and microphysics to first\necho.\nProcurement and assembly of a GOES weather satellite receiving and\nweather analysis system, with field tests in 1986, as provided by a\nspecial appropriation for instrumentation.\nInitiation of studies and modeling of convergence fields to improve\nforecasts of convective cloud activity.\n48","COOPERATIVE RESEARCH-UTAH/NOAA\nFY-1986 activities will focus on continued intensive analyses of the valu-\nable and comprehensive data sets from the 1985 field study of orographic\nclouds in the Tushar mountains. These analyses of cloud motions, liquid water\ndevelopment, and precipitation processes will address case studies and the\noverall season. Limited field work focused on tracer studies of plume trans-\nport, and delivery of seeding material may be undertaken as well.\nWMP\n49","","ATLANTICOCEANOGRAPHIC AND\nHugo F. Bezdek\nMETEOROLOGICALLABORATORY\nDirector\nMiami, Florida\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nESG\nSTORM\nTOGA\nCRP WRP PROFS WMP\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nWPL\nARL\nAL\nSEL\nThe Atlantic Oceanographic and Meteorological Laboratory (AOML) is organ-\nized to pursue basic and applied research programs in oceanography and trop-\nical meteorology. Oceanographic investigations center on fluxes of energy,\nmomentum, and materials through the air-sea interface; the transport and compo-\nsition (thermal and chemical) of water in the ocean volume; and hydrothermal\nprocesses of mineralization at seafloor-spreading centers. Meteorological\nresearch is carried out to improve the description, understanding, and predic-\ntion of hurricanes. The research program is enlarged by the Cooperative Insti-\ntute for Marine and Atmospheric Studies (CIMAS), a joint enterprise with the\nRosenstiel School of Marine and Atmospheric Science of the University of Miami.\nCIMAS enables NOAA and university scientists to collaborate on problems of\nmutual interest, and facilitates the participation of visiting scientists.\nAOML\nAOML's current research program concerns processes relating to climate,\nweather observation and prediction, marine assessment, marine observation and\nprediction, marine resources, and air quality.\nCLIMATE RESEARCH\nClimate research at AOML continues to focus on aspects of ocean heat\ntransport and storage in relation to interannual and longer term variations of\natmospheric weather and climate. AOML activities in these areas are part of\nthe NOAA contribution to national and international programs for climate\nresearch.\nMore and more, the scope of problems being addressed requires extensive\ncooperation and coordination between groups, especially for oceanographic\nfield programs. Tradition and convenient access to sea-going research facili-\nties result in a research program with emphasis on collection and analysis of\n51","oceanographic data. The ultimate goal of the work is to improve forecasting\nof oceanic and atmospheric variations using predictive models. Model develop-\nment per se is not a major part of the climate research program at AOML, but\nfocus is provided by the data needs of models, model-data interaction, and\nobservations for parameterization of physical processes in models and for eval-\nuation of models.\nThe AOML program in climate research is conveniently described within the\ntwo categories of tropical ocean climate studies and subtropical Atlantic\nOcean climate studies.\nAccomplishments FY 1985\nTROPICAL OCEAN CLIMATE STUDIES\nTropical ocean climate studies at AOML consist of participation in the\ncontinuing NOAA Equatorial Pacific Ocean Climate Studies (EPOCS) program, anal-\nysis and interpretation of tropical ocean data collected during the First GARP\nGlobal Experiment (FGGE) of 1979, and beginning work in connection with the\ninternational program Tropical Ocean and Global Atmosphere (TOGA), which has\nobjectives very similar to those of EPOCS, but which concerns all the tropical\noceans rather than just the equatorial Pacific Ocean. The common focus of\nthis work is to describe, understand, and predict the large-scale air-sea\ninteraction processes associated with the major mode of interannual large-\nscale climate variation--the El Niño/Southern Oscillation (ENSO) phenomenon.\nAn investigation was completed into the physical nature and implications\nfor modeling of prominent long waves regularly observed in the equatorial\noceans. Major results are that these waves affect a remarkably large equator-\nward heat transfer, which could be parameterized as a Fickian diffusion pro-\ncess but which has an extraordinarily large coefficient, and a significant\nmomentum transfer that cannot be parameterized in any conventional way because\nit is partially countergradient in direction.\nAn intensive investigation was conducted into the accuracy of linear\nmodels that represent the observed variations of the tropical oceans in terms\nof vertical modes. The principal results are that such models appear to be\ncapable of reproducing the variations that normally occur on relatively short\ntime scales, but that the important variations (such as ENSO events, which\noccur on longer time scale and whose prediction is of the highest priority)\nare fundamentally nonlinear, and are not likely to be quantitatively represent-\nable with linear models.\nSurface meteorological data and surface and subsurface oceanographic data\ncollected during FGGE (1979) in the tropical Atlantic and Indian Oceans were\nused to estimate the heat balance of the ocean surface mixed layer. Results\nshow that surface heat fluxes account for 75% of the variations observed in\nmany areas. In the Atlantic, addition of estimated zonal advection does not\nsignificantly improve the estimation. It was concluded that seasonal varia-\ntion in the intensity of vertical mixing across the base of the mixed layer is\nan important process in equatorial regions.\n52","An oceanographic atlas was published describing the El Niño event of\n1982-83. This atlas contains a broad comprehensive set of observations by U.S.\nscientists and those of other nations. It will serve for many years as the\ndefinitive summary of oceanographic observations that will be used for testing\nmodels and diagnostic studies of this historic event.\nDrifting buoy data collected from 1977 to 1983 in the eastern tropical\nPacific were used to estimate the rate of equatorial upwelling from the hori-\nzontal divergence of near-surface currents. An average upwelling rate of 1.5\n+ 0.3 m/day was found for the region 1.5°N-1.5°S, 80°-130°W. (This is the\nfirst estimate of equatorial upwelling with attendant error bars). Substan-\ntial annual and semiannual modulation, agreeing in phase with previous anal-\nyses of isotherm depth, were also found.\nThe mean dynamic topography of the Gulf of Mexico was computed from all\navailable Nansen bottle, CTD, and XBT data for investigation of the uses of\nsatellite altimetry. More than 26,000 stations were used to determine the\nmean dynamic height at 25 km resolution. The dynamic topography is dominated\nby the 150-dynamic-centimeter high associated with the Gulf Loop Current in\nthe eastern basin, and by a cyclone/anticyclone pair in the western basin.\nThe standard error of the mean is less than 2 dynamic cm.\nA new design was completed for a drifting buoy for measuring sea surface\ncurrents and temperature in the tropical oceans. This buoy is characterized\nby improved (and better documented) Lagrangian performance. It can be con-\nstructed and transported for less than one-third the cost of previous buoy\ndesigns and can be deployed easily from smaller vessels. It also is designed\nto take advantage of recent progress in development of data processing proce-\ndures which is expected to reduce the cost of data collection by at least one-\nhalf. It is anticipated that this drifting buoy will be used extensively in\nthe EPOCS and TOGA programs.\nFurther progress was made also in development of ocean sampling, in co-\noperation with research institutions in Latin America. Subsurface thermal\nsampling was begun from an Ecuadorian vessel operating between South America\nand Japan, and the equipment now used aboard two Ecuadorian vessels was upgrad-\ned to provide capability for real-time transmission of data for use in evaluat-\nAOML\ning predictive models of the El Niño phenomenon.\nSUBTROPICAL ATLANTIC CLIMATE STUDIES\nAnalysis of data collected during the 2-year intensive observing period\nin the Straits of Florida indicates that variability occurs on many spatial\nand temporal scales. Variability at periods ranging from days to several\nweeks occurs in both the baroclinic and barotropic components of the flow and\nfrequently takes the form of continental shelf waves. These waves are generat-\ned by local and/or regional wind forcing. The phase of the annual signal in\ntotal transport closely resembles the phase of the annual signal generated by\na wind-driven numerical model of the North Atlantic. The observed amplitude\nof the annual signal is approximately twice the amplitude of the model annual\nsignal. The amplitude of the interannual signal in transport as derived from\nsea level observations calibrated for transport is less than one-half the\nannual signal.\n53","In two cruises to the western North Atlantic Ocean, over-the-side observa-\ntions were taken, and in situ recording instruments were placed, following the\nphilosophy adopted in the Straits of Florida of using direct observations of\ntransport to calibrate indirect observations. The North Atlantic Deep Under-\ncurrent was observed directly for the first time at 26.5°N. Geostrophic obser-\nvations show that this equatorward flow, which apparently has a large role in\nmeridional heat flux, exists as far south as San Juan, P. R.\nParticular success was achieved also in implementing a system for\nacoustic remote sensing of currents from the R/V Researcher. Both the hard-\nware and the data-processing software place this system at the fore, in both\nreliability and accuracy, of the several similar systems that exist throughout\nthe world. It is notable that development of this system was not implemented\nprimarily as an engineering task at AOML, but rather was driven by scientist-\nusers who interacted with the engineering staff. Unprecedented views of the\nthree-dimensional ocean current structure have already been obtained using\nthis device, and it is serving as the model for installation on other NOAA\nships, and even research vessels of other nations.\nPlans FY 1986\nTROPICAL OCEAN CLIMATE STUDIES\nThe main focus of these studies will continue to be with the EPOCS and\nTOGA programs. A closer association with model developments is planned.\nStrategy will be developed for four-dimensional data assimilation in models;\nthat is, an investigation will be made of the use of observations to \"update\"\nmodel simulations in optimal ways. AOML has detailed a senior research ocean-\nographer to the NOAA National Meteorological Center to participate in imple-\nmenting and evaluating a general circulation model of the tropical Pacific\nOcean for simulation and experimental predictions of El Niño phenomena.\nCollection of surface current and sea surface temperature data by means\nof satellite-tracked drifting buoys will be substantially increased, using the\nnew drifting buoy design. An intensive program for observing and mapping the\nsurface currents in the region of the South Equatorial Current and North Equa-\ntorial Countercurrent will be conducted in the eastern tropical Pacific Ocean\nas part of EPOCS. Deployments of drifting buoys are planned also in the west-\nern Pacific Ocean in association with United States/Peoples' Republic of China\nfor the TOGA cooperative agreement program, and in the Arabian Sea and Bay of\nBengal as part of the TOGA program in the Indian Ocean. Initial deployments\nwill be used to explore the nature of these regions. Plans for future work\nwill be based on results from initial deployments.\nTwo research cruises are planned to investigate the currents and hydro-\ngraphic conditions in the southeastern tropical Pacific, farther offshore than\nheretofore studied in the EPOCS program. This is the region in which precurs-\nory indications of El Niño are seen in some historical data, and from which\nsome of the anomalous conditions observed near the coast during El Niño are\npresumed to be derived. Cooperation with scientists in oceanographic institu-\ntions in Latin America will continue, with the objective of assisting them to\n54","improve the quality and quantity of their observing projects for mutual\nbenefit.\nIf an El Niño event occurs during the year, AOML scientists will be in-\ntensely involved in augmentation of observations, using the NOAA research air-\ncraft as well as all the observing systems mentioned above.\nSUBTROPICAL ATLANTIC CLIMATE STUDIES\nThe program for long-term monitoring of the Florida Current using the\nmethods developed during the first phase of the work will be continued. The\nmajor emphasis for research during Phase 2, however, is to develop knowledge\nof the currents along the topographic rise on the eastern side of the Bahama\nIslands and in the Antillean passages. Continued observations of currents,\nsea level, pressure, and water properties will be made with shipboard and in\nsitu instrumentation\nIt is planned that in the more distant future this work will evolve into\na substantial part of the NOAA contribution to the World Ocean Circulation\nExperiment (WOCE). Although the particulars of the objectives and observing\nstrategies for WOCE are still undecided, it is certain that measurements such\nas those currently being changed to operational status on the Straits of the\nFlorida will be critical.\nWEATHER OBSERVATION AND PREDICTION\nAOML is NOAA's primary focus for research in tropical meteorology and\nhurricanes. Research teams concentrate on field programs, numerical hurricane\nmodeling, and theoretical studies of hurricanes. The Laboratory's hurricane\nfield program uses NOAA research aircraft to acquire unique data sets. AOML\ninteracts with the National Hurricane Center (NHC) and the National Meteorolog-\nical Center (NMC) of the National Weather Service (NWS) in problems of hurri-\ncane prediction, with the National Center for Atmospheric Research (NCAR) on\nscientific investigations of the inner cores of hurricanes, and with the Geo-\nAOML\nphysical Fluid Dynamics Laboratory (GFDL) in the area of hurricane modeling.\nAccomplishments FY 1985\nOBSERVATIONAL STUDIES OF HURRICANES\nMicrophysics\nA study on the distribution of ice in the convective elements of Hurri-\ncanes Ella (1978), Allen (1980), and Irene (1981) showed that above the 0°C\nlevel only updrafts greater than 5 m S - 1 contained liquid precipitation.\nDowndrafts contained very high concentrations of ice particles and were always\nadjacent to updrafts greater than 5 m s-1. Graupel was the predominant par-\nticle type in the convective regions. Irregular particles, similar in appear-\nance to aggregates, predominated elsewhere.\n55","An analysis that correlated particle type and concentration with the PPI\nradar display for Hurricanes Allen (1980) and Irene (1981) showed that regions\nof high (>30 dBZ) radar reflectivity above the 0°C isotherm were positively\ncorrelated with strong updrafts and with the presence of liquid precipitation.\nStrong radial gradients of radar reflectivity in the outer edge of the eyewall\nwere frequently associated with downdrafts and high concentrations of ice par-\nticles.\nConvective-Scale and Mesoscale Features\nAnalysis of airborne Doppler radar data from Hurricane Alicia (1983) near-\ned completion. It was possible to map the secondary circulation in the eye-\nwall, including the radial inflow at low levels, the updraft along the inside\nedge of the eyewall, and the radial outflow at the top of the eyewall. The\nradial outflow was concentrated in a relatively narrow layer, 2-3 km thick, at\nthe top of the storm.\nThe airborne Doppler system provided direct measurements of the mesoscale\nverticle motions in the nonconvective or stratiform region surrounding the\neyewall. Both updraft and downdraft air motions were found to originate at\nthe 0°C level. This is consistent with recent modeling results obtained at\nAOML. The magnitude of these mesoscale vertical motions was 30-80 cm s-1,\nwhich is comparable with those in other tropical systems.\nAOML's land-based radar project is concerned with analysis and interpreta-\ntion of digital land-based radar data recorded at NWS offices during the land-\nfall of hurricanes. The emphasis is on the description of important changes\nin the patterns of rainfall that are caused by land influences, the statisti-\ncal properties of the convective-scale and mesoscale features of hurricane\nrainbands, and the life history and three-dimensional structure of the convec-\ntion. During FY 1985, the project produced a color time-lapse movie of the\ndigital radar data that were recorded during the landfall of Hurricane Alicia\n(1983). A second movie of landfalling Hurricane Diana (1984) neared\ncompletion.\nDetailed observations of supercell activity were obtained in eastern\nPacific Hurricane Norbert (1984). Doppler radar data, lower fuselage reflec-\ntivity data, cloud microphysical data, aircraft wind and thermodynamical data,\nand remotely measured surface wind data were obtained. Preliminary analysis\nreveals a remarkable similarity with a previous supercell case--Hurricane\nGladys (1975). Supercell locations (with respect to the low-level circulation\ncenter), as well as horizontal scales and magnitudes of reflectivity features,\nwere nearly identical. Both cases were characterized by intense downdrafts\n(>15 m s - 1) downwind of the convective cores (some with reflectivity >50 dBZ)\nextending through 500- and 700-mb levels. This resulted in relative humidi-\nties of less than 30% and temperature anomalies of nearly 20 o C at 700 mb.\nSynoptic Environment\nThe steering currents on the periphery of mature hurricanes are determin-\ned by Omega dropwindsondes (ODWs), which are deployed from NOAA P-3 aircraft.\nThe ODWs measure temperature, relative humidity, and pressure, and transmit\n56","data to the aircraft. They also receive and retransmit Omega navigational\nsignals, which allow horizontal winds to be computed. With the ODW observa-\ntions, the synoptic-scale flow around a hurricane can be determined from the\nsurface to 400 mb more accurately than is possible with the current operation-\nal data sources.\nExperiments were conducted on three days during flights in the periphery\nof Hurricane Josephine in October 1984. The spatial scale of Josephine's cir-\nculation was slightly larger than 1000 km. The operational objective analysis\nat NMC, however, is able to resolve only scales that are generally greater\nthan 1500 km. The analysis resolved the larger scale aspects of Josephine's\ncirculation but did not respond well to ODW observations within 500 km of the\nstorm center. Differences between the analyses computed with and without the\nODW data were very small. Track forecasts computed by the Movable Fine-Mesh\n(MFM) model were also not changed significantly by the ODW data.\nThe MFM errors in the track forecasts at 12 h were particularly large in\ncomparison with climatology-persistence forecasts made by the CLIPER model.\nSince the MFM became operational, its 12-h track forecasts have consistently\nbeen worse than those made by CLIPER. It was previously thought that poor\nperformance of the MFM forecasts at 12 h was the result of the lack of data\nnear the center of hurricanes. It now appears that the insensitivity of the\nMFM track forecasts to the ODW data and the consistently poor track forecasts\nat 12 h are a result of the inability of the operational objective analysis to\nadequately resolve the hurricane circulation.\nWe are attempting to develop an objective analysis scheme for the large-\nscale environment of hurricanes which incorporates ODW and other available\ndata such as rawinsonde, NOAA P-3, and Air Force reconnaissance data. A set\nof horizontal analyses of winds, temperature, relative humidity, and geo-\npotential height for Hurricane Debby (1982) was completed. The analyses are\nat 50-mb intervals from 100 mb to the surface. Data input for the analyses\ncomes from ODWs, Caribbean and U.S. rawinsondes, NOAA P-3 and Air Force recon-\nnaissance aircraft, surface ships, commercial aircraft, University of\nWisconsin satellite data and derived products, and NMC operational analyses.\nThe raw data were carefully edited to promote consistency between the various\ndata sources before input to the analysis package. An iterative scheme was\nAOML\ndeveloped to couple the horizontal analyses vertically by creation of bogus\ndata where the analyzed fields are noisy. This occurs most often in data-void\nregions. Results of the first tests were very encouraging.\nAir-Sea Interaction\nTwo hurricane air-sea interaction experiments were conducted in 1984.\nSystematic measurement of ocean currents, using airborne expendable current\nprobes (AXCPs), was carried out in Hurricane Norbert. Ocean current profiles\nwere obtained which enabled patterns of mixed layer and sub-thermocline\ncurrents to be mapped. Vertical wind profiles in the Hurricane Planetary\nBoundary Layer (HPBL) were obtained using airborne Doppler radar; surface\nwinds were obtained using the University of Massachusetts stepped-frequency\nmicrowave radiometer (SFMR).\n57","The experiment was repeated in Hurricane Josephine, where three drifting\nbuoys were also deployed by USAF aircraft immediately ahead of the storm.\nMeasurements of surface winds and pressures, sea temperatures at four depths,\nand data obtained from AXCPs and research aircraft during Hurricane Josephine\nmade it one of the most thoroughly observed storms from an air-sea interaction\nviewpoint.\nSFMR data were taken in Hurricanes Norbert, Josephine, and Isidore. Data\nquality was excellent for all cases. Calibration constants for converting\noutput voltages to microwave brightness temperatures and surface wind speed\nare being derived.\nHURRICANE TRACK PREDICTION\nResearch to improve the barotropic hurricane track forecast model\n(SANBAR) used operationally at NHC has been in progress for several years. In\nFY 1985, a revision was made to the method by which the model calculates the\nvorticity and the stream function in the vicinity of the hurricane. The revis-\nion reduced discontinuities in the fields near the storm and produced a defin-\nite improvement that resulted in reduction of average forecast errors when a\nfine-grid version of the model was used. The average errors showed a statis-\ntically significant reduction for the 12-48 h forecast intervals.\nHURRICANE VORTEX DYNAMICS\nData collected in Hurricanes Diana (1984) and Alicia (1983) offer substan-\ntial confirmation for the convective ring model in which tropical cyclones\nundergo cyclic changes of intensity and eye size. The observations also docu-\nment Diana's intensification from a tropical storm to a category-four\nhurricane.\nResearch to understand the nonhydrostatic convective dynamics of hurri-\ncanes is in progress. A fine-resolution (2 km horizontally and 1 km vertic-\nally) axisymmetric model is being used to examine factors that affect the\nstructure and evolution of the simulated storm. Recent emphasis has been on\nthe role of ice-phase microphysics. Statistical analyses of four versions of\nthe model with different microphysical parameterizations show a definite \"ice-\nphase signature\" in the strength and horizontal scale of downdrafts near the\nmelting level. Frequencies of stronger downdrafts with larger horizontal\nscales increase at and below the melting level, whereas no vertical variation\nis present when the ice phase is not included.\nQUASI-SPECTRAL HURRICANE MODELING\nTo achieve substantial improvement over existing operational models, it\nis necessary to understand various physical and dynamic factors affecting the\nmotion of a hurricane, and to test new ideas with a quantitatively accurate\nnumerical model. A general-purpose base model on nested grids is under\ndevelopment, utilizing an accurate and flexible numerical method, QSTING\n(Quasi-Spectral Time Integration on Nested Grids).\n58","Spectral representation of field variables by cubic B-splines is the\nbasis of QSTING. It combines the numerical accuracy of spectral methods with\nthe freedom of specifying boundary conditions to a finite domain. To nest a\nseries of finite domains of differing resolution is a modeling assumption that\nforces compromise on the obtainable mathematical solutions. Our concern is to\nreduce the compromise to a physically acceptable level. The acceptable level\ndepends on the physical problem. Its achievability depends on numerical tech-\nniques.\nThe problem of wave propagation across an interface, from a fine-\nresolution domain to a course-resolution domain and vice versa, was solved\nearlier by dynamically matching spatially variable filters at the interface.\nWe were aware of another problem with the Gibbs phenomena, which arose from a\nstrong stationary disturbance in a fine-resolution domain when the disturbance\nwas projected on the same area embedded within the next larger domain. The\nprojection entails spectral truncation due to a change in resolution. By care-\nfully designing projection filters, we reduced the error to a level that we\nhad once thought to be acceptable. However, as soon as the plane QVADIS was\ntested with a balanced free-spinning hurricane-like vortex, we were shown to\nbe wrong. Although the error at each time step was small, it accumulated, and\nafter 8 h (2880 time steps) the vortex was noticeably out of the original\nshape and definitely unacceptable.\nA solution to the problem is to eliminate the projection entirely. That\nis, we accept each nested domain with a hole in the middle where no informa-\ntion exists. (Earlier, there was no hole of information, since the area was\nfilled with the projection, or \"shadow\", of the subdomain fields.) The new\nprocedure technically implies performing spectral transforms in a domain with\na hole, without knowing the explicit inside boundary conditions. Because of\nthis and other technical complications associated with holed domains, we had\nstayed with the projection method too long. When proper algorithms were devel-\noped and the new QSTING-anumbra (meaning \"without shadow\") was reprogrammed,\nthe model worked beautifully. The free-spinning vortex now keeps spinning\nwith very little change.\nOBJECTIVE ANALYSIS OF TROPICAL WINDS\nAOML\nNHC has archived twice-daily objective analyses of ATOLL (Analysis of the\nTropical Ocean Lower Layer) (nominally about 900 mb) and 200-mb winds over the\ntropical Atlantic for June through November since 1975 and for the entire year\nsince 1981. Spectra of selected locations in the tropics show substantial\nvariation in the 3-5 day \"easterly wave\" band. In the \"data-rich\" subsection\nof the grid from 40 °W to 100 °W and 10°N to 30°N, the analyses were sampled on\nan approximate 3° grid, and filtered in time to isolate energy in the 3-5 day\nband. Complex tensor covariance statistics were used to analyze the spatial\nstructure and temporal (month to month) variability within the band. Complex\nEmpirical Orthogonal Functions (EOFs) were used to extract the dominant\nspatially coherent signal. The complex EOFs include information on the three-\ndimensional structure, including phase propagation, for the individual modes.\nConsiderable temporal variability and spatial inhomogeneity were found in\nthe monthly statistics. In July-September of 1975-1977, only July 1975 and\none month in 1976 had dominant EOF modes that were statistically distinct from\n59","the lower ones. In July 1975 there was a series of strong easterly waves in\nthe Atlantic and Caribbean that were well defined over a large portion of both\nthe 200-mb and ATOLL analyses. The first EOF, explaining 25% of the total\nvariance, had large amplitude at both levels. The phase lines of the dominant\nmeridional wind component sloped somewhat from southwest to northeast at the\nATOLL level and tilted westward with height against the mean westerly wind\nshear. The zonal wavelength at both levels was about 3500 km, corresponding\nto a westward phase speed of about 9 m s-1. Vorticity amplitude and phase\nwere also computed. The extension of the mode to the west showed vorticity\nphase propagation continuing across the Atlantic, the Caribbean, Central\nAmerica, and Mexico, and into the region of tropical storm formation in the\neastern Pacific.\nGALE\nThe Genesis of Atlantic Lows Experiment (GALE) should provide new infor-\nmation on coastal frontogenesis and cyclogenesis and the mesoscale structure\nand evolution of cyclones. The field experiment is scheduled for the Carolina\ncoastal region from 15 January to 15 March 1986. During 1985, AOML's portable\nradar recorder was taken to the NWS office in Wilmington, N.C. Weather Ser-\nvice personnel operated the recorder and recorded data in four weather events\nbetween 30 January and 22 March. PPIs were recorded every 6 min. The data\nwere processed and a color time-lapse movie was completed and distributed to\ninterested GALE scientists. The movie is being used to plan observing strate-\ngies for the field experiment.\nSTORM\nMesoscale convective systems (MCSs) produce significant rainfall and se-\nvere weather in the Midwest during the spring. Two of the main goals of the\nStormscale Operational and Research Meteorology (STORM)-Central research pro-\ngram are to improve understanding of the genesis, evolution, and structure of\nMCSs, and to improve forecasts of MCSs. The field phase of the Preliminary\nRegional Experiment, PRE-STORM, took place in Oklahoma and Kansas (OK) in\nspring 1985. The goals of OK-PRE-STORM were to investigate mesoscale\nconvective systems. One of the sub-goals was to observe microphysical\ncharacteristics and radar characteristics of mesoscale convective systems.\nAOML participated in the field phase of PRE-STORM by recording digitized radar\nreflectivity at the Wichita NWS WSR-57 radar, and by collecting microphysical\ndata on the NOAA P-3 aircraft. These data, and the data collected by the NCAR\nDoppler radars and the portable automated mesonetwork (PAM), will be used to\nstudy the initiation and evolution of the stratiform precipitation region, the\nprecipitation mechanism (s) in the stratiform region, and feedbacks into the\ndynamics of the mesoscale convective systems.\n60","Plans FY 1986\nOBSERVATIONAL STUDIES OF HURRICANES\nMicrophysics\nA study of the melting layer in Hurricane Alicia (1983) will be complet-\ned. Data taken in stratiform regions of hurricanes and PRE-STORM data from\nstratiform regions in MCSs will form the basis for a comprehensive study of\nstratiform precipitation. The analysis and interpretation of the microphys-\nical data from the Hurricane Norbert (1984) water budget experiment will\ncontinue.\nConvective Scale and Mesoscale Features\nThe primary emphasis will be on analysis of the water budget in Hurricane\nNorbert (1984). The airborne-Doppler analysis will be completed and integrat-\ned with the analysis of the flight level and microphysical data. The water\nbudget equations will be formulated and the terms evaluated. Analysis of the\nvisual and radar-derived characteristics of Hurricane Diana's (1984) eyewall\nwill be completed. The three-dimensional structure of the convective-scale\nand mesoscale features in Hurricane Alicia (1983) will be examined with both\nland-based- and airborne-radar data.\nSynoptic-Scale Environment\nCooperative studies with NHC and NMC will continue to examine the effect\nof the ODW data on the operational analyses and hurricane track models. The\ndata will be used in diagnostic and prognostic studies of hurricanes and in\nthe evaluation of remote atmospheric soundings.\nAir-Sea Interaction\nIt is planned to acquire additional color photographs of sea state for\nAOML\nuse in developing color descriptions of sea state corresponding to Beaufort\ncategories 3 through 19. Photos will be compared with SFMR measurements.\nThis study will also use Inertial Navigation System flight level wind measure-\nments made near cloud base, and planetary boundary layer (PBL) models, to re-\nduce flight level winds to the surface. Airborne Doppler radar measurements\nin the PBL will also be used for estimating surface winds. It is planned to\ndevelop a surface wind speed algorithm for use with SFMR data in real time.\nHURRICANE VORTEX DYNAMICS\nWork will be directed toward preparation of the confirmatory concentric-\neyewall observations for formal publication and toward exploration of addition-\nal aspects of Hurricane Alicia (1983), Arthur (1984), and Diana (1984) that\nrelate to vortex motion and banded structure. Theoretical vortex-motion work\nwill focus on detailed exploration of a barotropic model from which prelimin-\nary results indicate that it may be possible to explain trochoidal motion of\n61","the vortex through resonance between a normal mode oscillation and periodic\nforcing by rotating steering currents.\nQUASI-SPECTRAL HURRICANE MODELING\nIt is necessary to understand, and extend, the concept of nonlinear diffu-\nsion. Some form of nonlinear diffusion that responds to in situ needs for\ndiffusion is desirable. The deformation-dependent diffusion, as originally\nproposed by Smagorinsky, is too indiscriminately diffusive. The need for\ndiffusion depends on both the spectral resolution of the model and the physi-\ncal problem to be solved. Therefore, the question straddles the border of\nnumerics and physics. We must also examine inertial instability in the hurri-\ncane upper-outflow layer. Upper-level outflow jets associated with organized\ncumulus convection have attracted many diagnostic studies. We would like to\nprovide a better theoretical explanation of these features.\nIt is hoped that QVADIS can be converted by October to the extent that it\nwill run on the CYBER 205. However, vectorization of the program under the\n205 rules requires extensive changes using nonstandard special routines of the\n205. Also, the conversion of QVADIS's interactive output program must also be\naccomplished as soon as possible.\nOBJECTIVE ANALYSIS OF TROPICAL WINDS\nAnalysis of the characteristics of the disturbances in the 3-5 day band\nwill be completed for 1975-1977. Statistical analyses of rawinsonde station\nprofiles will be made to describe the vertical structure of the disturbances.\nSpectral and EOF techniques will be used to investigate the long-term\ninter- and intra-annual variability in the wind data since 1975. The relation-\nship of the wind variability to climatic fluctuations, such as the El Niño/\nSouthern Oscillation, the 30-60 day global oscillation, and hurricane cycles\nwill be examined. Work to provide a climatology of the winds, including\nmonthly means, will be started.\nGALE\nAOML's existing radar recorder and two new recorders will record data at\nWeather Service stations during GALE. Five or six AOML scientists will partic-\nipate in the field experiment for periods ranging from 2 weeks to a month.\nThey will operate instruments on the NOAA P-3 during flights, ensure that the\nportable radar recorders are operating properly, and provide advice in the\ndesign of Omega dropwindsonde flights. Plans are being developed for coopera-\ntive research on coastal fronts with Pennsylvania State University and the\nState University of New York at Albany and on the mesoscale structure of\noceanic rainbands with the University of Washington.\nSTORM\nThe PRE-STORM data set contains 1000 tapes of Doppler data from the two\nNCAR radars and 200 tapes of digitized radar data from the Wichita WSR-57. A\n62","necessary first objective for 1986 is to produce an overview of eight or nine\nnotable weather events, using the digitized WSR-57 data. This overview is\nexpected to help focus the subsequent analyses of the Doppler, the surface,\nand the aircraft data sets.\nOBSERVATIONAL STUDIES OF THE SOUTH FLORIDA SEA BREEZE\nThe field phase of the sea-breeze experiment, carried out in previous\nyears, was designed to provide a description of the mixed layer, the cloud\nlayer, and the evolution of the sea-breeze circulation from shortly after sun-\nrise until midafternoon when deep convection is normally present. The role of\nthe sea-breeze in organizing the development of deep convection is being exam-\nined. Airborne Doppler radar data, collected on two days, are being used to\nspecify the kinematic structure of mesoscale precipitation lines that were\ninitiated by the sea-breeze circulation. Analysis of the aircraft data will\nbe completed as will analysis of airborne Doppler radar observations of the\ndevelopment of deep convection in the sea-breeze convergence zone.\nAIR QUALITY\nAir quality research at AOML has two focuses. One is to develop an under-\nstanding of the geochemical cycles (horizontal and vertical distributions,\nsources, sinks, and transformation processes) of major trace constituents of\nthe atmosphere. The second component concerns studies of the role that marine\nbiological processes have in determining the composition of the atmosphere.\nAt present, both programs are addressing those species (excluding carbon diox-\nide) that are significant in determining the Earth's radiation balance. The\noverall objective of this research is, in conjunction with AL, ARL, GFDL, and\nPMEL, to develop a validated diagnostic and prognostic ability to assess cli-\nmate alterations resulting from observed or projected changes in the radiative-\nly important trace species (RITS).\nAOML\nAccomplishments FY 1985\nACID RAIN\nAOML completed its interim assessment of the role of oceanic processes in\ndetermining the acidity of precipitation. This assessment was called for in\nthe National Acid Deposition Assessment Program plan and was based on 3 years\nof research cruises to study chemical and biological processes in oceanic re-\ngions. Though emphasizing the biogeochemistry of sulfur, the research studied\na wide variety of precursors of acidic species, such as the precursors of or-\nganic acids, and processes that transform precursors into acidic species, such\nas oxidation. The major findings of the assessment were that the combined\nfluxes of reduced sulfur from marshes, estuaries, and oceanic regions to the\ncoterminous 48 states were insignificant (<10% and most likely only 1-5%) com-\npared with the anthropogenic fluxes. On a regional scale, however, such natur-\nal sources could be significant to the sulfur budget of the west coast. It is\nalso possible that marine sources of reduced sulfur may affect the immediate\n63","Gulf Coast but are rapidly removed within 100 miles or so inland. Marine\nsources are not significant on the east coast. On a global scale, no evidence\nwas found indicating that published data on levels of reduced sulfur over\noceanic regions are in error and, consequently, that fluxes derived from those\nmeasurements are incorrect. However, we cannot balance these fluxes on the\nbasis of what we have learned about the biogeochemistry of sulfur. A large\nflux of biogenic sulfur from the marine environment to the atmosphere cannot\nbe substantiated by our experimental evidence on inorganic sulfate assimila-\ntion by marine organisms and the subsequent partitioning within biochemical\nsystems.\nRITS\nAOML continued its marine tropospheric chemistry program as part of the\nERL RITS effort. Equipment and apparatus were built and acquired. Spectro-\nmeters, chromatographs, sampling systems and chemical standards were accumu-\nlated.\nWork continued on the analyses of the volatile organic components in a\nsuite of samples collected over the Pacific in 1984. These reactive and radia-\ntively important trace substances have very large variability in concentration\nin both space and time. The different compositions of the mixtures are probab-\nly related to their biogenic source. Vertical profiles of the volatile organ-\nics, collected from the NOAA P-3, show that the chemistry of many of the compo-\nnents is confined to the lower few hundred meters over the sea surface.\nOther, more stable, constituents mix throughout the boundary layer. Ozone\nconcentrations were measured constantly throughout the organic sampling on\nshipboard and on the aircraft. It is not clear from the data in hand whether\nthe organics evaporating from the sea surface are sources or sinks of ozone.\nHigh concentrations of many organic oxidation products were identified in the\nboundary layer. These observations will be investigated in more detail in FY\n1986.\nPlans FY 1986\nACID RAIN\nAOML's research into the role of oceanic processes in determining the\nhydrogen ion content of precipitation ended in FY 1985. The principles and\napproaches developed in that program will continue to be applied within our\noverall research program into biosphere, hydrosphere, geosphere, and atmos-\nphere interactions. Much of this will occur within the scope of our RITS pro-\ngram. Some specific questions that arose in the course of our acid rain re-\nsearch, such as balances between biological and geochemical cycles of atmos-\npheric trace species, are generic components of biogeochemical research pro-\ngrams and are likely to be addressed within the RITS program.\n64","RITS\nThe AOML tropospheric chemistry effort will concentrate on the tropical\nAtlantic. More chemical species will be measured synoptically along with all\nrelevant meteorological data. Methane, carbon monoxide, ozone, nonmethane\nhydrocarbon gases, and the volatile organic liquids will be measured at the\nsea surface. In addition, detailed vertical profiles, up to cloud base, of\nozone and the volatile organics will be determined with a new tethersonde\nsampling package. Finally, if funds are sufficient, the biogenic origin of\nthe reactive and radiatively important organics that evaporate from the sea\nsurface will be investigated. The very large qualitative and quantitative\ndifferences observed in time and space indicate that the release of this broad\narray of compounds is intimately associated with biological cycles and ecologi-\ncal microcosms. The relationships between these living systems and the chemi-\ncal/physical environment of the sea should be quantified.\nMARINE RESOURCES\nThe AOML contribution to studies in Marine Resources is directed toward\ndetermining the chemical and thermal effects on the ocean of hydrothermal vent-\ning from representative sections of the slow-spreading Gorda Ridge and Mid-\nAtlantic Ridge. These efforts are central to the program objectives of the\nNOAA VENTS program.\nAccomplishments FY 1985\nGORDA RIDGE\nThe objective of the FY 1985 program was to determine the state of hydro-\nthermal activity on the Gorda Ridge. Toward this end, a number of investi-\ngators participated in a cruise of the NOAA Ship Surveyor (May 1985).\nSelected accomplishments are as follows:\nAOML\nAll existing NOAA and USGS geological and geophysical data on the Gorda\nRidge were reviewed and applied to selecting target sites for the May\n1985 VENTS Program cruise, in close collaboration with USGS scientists\n(Marine Geology and Geophysics Branch, Menlo Park).\nAOML participated in the May 1985 Surveyor cruise to the Gorda Ridge, to\ncollect suspended particulate matter, sediment cores, interstitial water,\nnear-bottom water temperature profiles, seafloor imagery, and SEABEAM\nprofiles at preselected target sites, in close collaboration with\nparticipating scientists from NOAA/PMEL and Oregon State University.\nPreliminary energy dispersive analysis (EDA) of the suspended particulate\nmatter showed enrichment of particulate iron, manganese, calcium, and\nsulfur, suggesting the presence of anhydrite; the iron enrichment is in\nthe form of relatively large (~10 um) subhedral to euhedral particles,\nin contrast to iron particles in suspended particulate matter (SPM) of\nthe Mid-Atlantic Ridge, which are in the colloidal range.\n65","Initial extractions of metals (Cr, Cu, Fe, Mn, and NiO) indicated\ndistinct variations in concentration, which are being interpreted in\nterms of remobilization under changing redox conditions and variations in\nhydrothermal input to the sediment column. Copper, Fe, Mn, and Ni\nexhibit a strong positive correlation in their distribution; Cr is\nnegatively correlated with these metals.\nThree camera-temperature profiles were run with SEABEAM bathymetry at\nsites where water chemistry indicated intermediate levels of hydrothermal\nactivity on the central Gorda Ridge; review and reduction of these data\nare being coordinated with heat flow measurements (Oregon State\nUniversity) and seismic reflection profiling (USGS) to determine\nrelations between hydrothermal activity, heat transfer, and crustal\nstructure.\nShipboard analyses of interstitial water revealed high redox states and\nconsequent remobilization of metals, particularly manganese, related to\nrelatively high contents of organic matter in the sediments; this result\nindicates that remobilization of metals and expulsion of the metal-rich\nwater during sediment compaction may have a significant effect on ocean\nchemistry, in contrast to the Mid-Atlantic Ridge where oxidizing\nconditions were found to prevail in the sediments and metal\nremobilization was negligible.\nMID-ATLANTIC RIDGE\nThe objective of the FY-1985 program was to locate and characterize the\nactual venting zone at a site where active venting was identified on the VENTS\nProgram FY-1985 cruise of the NOAA Ship Researcher. Accomplishments of the\ncruise (9 July-7 August 1985) are as follows:\nHigh-temperature black smoker-type venting was discovered at the\nTrans-Atlantic Geotraverse (TAG) Hydrothermal Field in the rift valley of\nthe Mid-Atlantic Ridge at latitude 26°N. This is the first high-\ntemperature black smoker venting found on a slow-spreading oceanic\nridge. Slow-spreading oceanic ridges constitute more than half the\nglobe-encircling, 55,000-km oceanic ridge system. The implication of the\ndiscovery is that hydrothermal venting from slow-spreading oceanic\nridges, including the Gorda Ridge, has a significant impact on the\nchemistry and heat budget of the oceans and offers potential for the\noccurrence of polymetallic sulfide deposits.\nIn the search and discovery process, the FY-1985 cruise collected\nmultidisciplinary data sets at far, intermediate, and near fields with\nreference to the black smokers. The data sets comprise water samples\n(suspended particulate matter, dissolved manganese, dissolved rare earth\nelements, dissolved gases), water properties (salinity and temperature\nand particulate light-scattering profiles), near-bottom temperature\nprofiles, moored oceanic current meter arrays, bottom sediments (cores,\ngrabs, sediment traps), rocks, imagery, and some biological material.\n66","Plans FY 1986\nGORDA RIDGE\nA NOAA cruise will be organized to examine a hydrothermal venting zone at\nwhat appears to be the most promising site or sites on the Gorda Ridge (an\nevaluation based on prior NOAA, USGS, OSU, and other work): the cruise will be\na collaborative effort of NOAA (AOML, PMEL), USGS, OSU, and others. The objec-\ntive of the FY-1986 cruise is to observe the active vents at close range and\nto characterize their effluents, building on findings from prior cruises.\nMID-ATLANTIC RIDGE\nThe possibility of a modest series of dives with the submersible Alvin is\nbeing explored to follow through on the discovery of black smokers at the TAG\nHydrothermal Field on the Mid-Atlantic Ridge. The scientific objective of the\ndives would be to sample the hydrothermal effluents and precipitates, measure\ntheir temperatures, and make related detailed investigations to determine chem-\nical and thermal fluxes, mineralization, and associated geologic setting of\nthe venting. A multidisciplinary, multi-institutional group to carry out the\ndive series and subsequent data reduction would include NOAA scientists (AOML,\nPMEL) with NOAA funding support, and MIT and WHOI scientists with outside fund-\ning (e.g., NSF).\nMARINE OBSERVATION AND PREDICTION\nAOML research in Marine Observation and Prediction is concentrated in the\nfollowing areas: (1) Improving the definition and measurement of the ocean\nbottom depth for charting, navigation, and bathymetric purposes; (2) determin-\ning optimum measurement system configurations for flux of volume, heat, partic-\nulates, and other parameters as they are used in NOAA Climate Programs and\nMarine Assessment Programs; (3) potential operational system evaluation and\ndemonstrations. This research is aimed at improving the observational equip-\nAOML\nment and techniques that are used to collect data on the marine environment;\nparticular emphasis is placed on the use of new, advanced, high-technology\nsystems.\nAccomplishments FY 1985\nECHO FORMATION MODELS\nAOML personnel developed an initial bottom-echo-formation model. When\ngiven a set of input parameters characterizing a bottom environment, the model\nwill produce the echo signal to be expected from such a bottom. The signal\nthus produced is extremely detailed and is used to evaluate different methods\nof echo signal processing and displays. Thus far the model has indicated that\nthe identification and classification of different bottom types is feasible.\n67","OPERATIONAL SYSTEM EVALUATION\nEstablishment of an initial theoretical basis for optimum flux and other\nmeasurement systems and arrays was carried out. The theoretical framework\nproduces the basis for determining an optimum set of instruments and their\nplacement in strategic regions in order to achieve specific measurement goals.\nAn experiment to evaluate the performance of the AOML transverse Doppler\ncurrent-profiling technique in a highly turbulent channel, the entrance to the\nPort of Miami, was carried out. Data from this equipment are being evaluated.\nA plan for AOML to participate in an operational demonstration of Coastal\nOcean Dynamics Applications Radar (CODAR) in the Straits of Florida between\nMiami and Fort Lauderdale was approved by the directors of AOML, WPL, NWS,\nNOS, and the USCG. A contractor was hired by NOS to refurbish, update, in-\nstall, and operate the NOAA-furnished equipment for the first 2 months.\nFLORIDA ATLANTIC COAST TRANSPORT STUDY (FACTS)\nField measurements of satellite-tracked Lagrangian drifters and inverted\necho sounder/pressure gauges (IES/PGs) near Cape Canaveral were completed in\nMay. Three areas west of the Gulf Stream were identified as locales where\ndrifters tend to come ashore: south of Cape Canaveral, Fla. near Jackson-\nville, Fla. ; and near Charleston, S.C. Data from two of the three deployed\nIES/PGs were recovered; the linear correlation with the STACS cable transport\nwas 0.83, and as in the Subtropical Atlantic Climate Study (STACS), most of\nthe signal was on the western side of the Gulf Stream. IES/PG pairs are use\nful indicators of volume transport when cables and/or surface tide gauges are\nnot available.\nPlans FY 1986\nECHO FORMATION MODELS\nAOML intends to continue the development of the bottom-echo-formation\nmodel. A field experiment for model validation is planned. It will probably\nbe conducted within Chesapeake Bay, and will be designed to obtain actual data\non echo formation by different bottom types. A comparison will be made be-\ntween the echos recorded in the field and the echos predicted to exist by the\nAOML echo-formation model.\nOPERATIONAL SYSTEM EVALUATION\nResearch into optimum measurement system configurations will continue,\nusing a mixture of local, integral, and remote measurement systems. Appli-\ncation of empirical orthogonal function theory to climate and other program-\ndictated measurement sections is planned. Continued reduction of sediment and\nparticulate transport data, obtained using acoustical systems, is anticipated.\nRoutine operation of the CODAR at Straits of Florida sites will be turned over\nto NOAA by the contractor in February. AOML will transfer the day-to-day pro-\n68","cessing and public information broadcasts to NWS, and will continue to conduct\nverification tests jointly with the USCG. Research into the use of operation-\nal CODAR data for monitoring the Florida Current and for nowcasting of sea\nstate will begin at AOML.\nFLORIDA ATLANTIC COAST TRANSPORT STUDY (FACTS)\nAnalysis of the AOML-obtained Lagrangian drifter data and the IES/PG data\nwill be completed. In addition to the AOML data, information from 44 moored\ncurrent meters, numerous Pegasus casts, sea level/weather gauges, and a sub-\nmarine cable are available for multi-input linear and spectral analysis. In\naddition to an assessment of the impact on Florida of mineral-mining opera-\ntions between Palm Beach and Jacksonville, the FACTS section will be subjected\nto a synergistic systems analysis to determine the optimum combination of\nmeasurements for an initiative in monitoring critical ocean regions.\nMARINE ASSESSMENT\nThe ocean, particularly the coastal ocean, is an invaluable environmental\nresource. Among its many uses, it is at one time a source of food and a recep-\ntacle for anthropogenic wastes. It is vital to our national interests to en-\nsure maximum compatibility of our various uses. We believe that trace metal\nspeciation processes in environments receiving waste inputs may play a major\nrole in determining what, if any, ecological cost will be associated with pol-\nlution. The most economically significant living resources in coastal waters\nare fisheries; however, owing to the time and space scales of actual and proba-\nble pollutant inputs, the most critical ecological events concern phytoplank-\nton. Perturbations once initiated, however, can cascade through the food web\nand indirectly affect fisheries.\nIt is important to recognize that stress from pollution may not be inher-\nently pernicious. We have reason to believe that it will be possible to devel-\nop effective strategies not only to minimize bad effects but perhaps to opti-\nmize desirable ecosystem transformations. Because of the potential impact on\nAOML\nthe coastal zone environment, we are faced with a need for developing intelli-\ngent choices for waste disposal; one option is ocean dumping. However, prob-\nlems at active bulk dump sites like those in the New York Bight have turned\nmany people against the ocean disposal alternative. We hypothesized that\nmajor rivers with high suspended sediment loads can adequately handle a signif-\nicant pollutant burden and that river deltas are a reasonable choice for con-\ntrolled, passive waste disposal. Rivers are the major pathway by which the\nproducts of natural geological erosion processes and the pollutant inputs of\nmankind are added to the oceans. Since most river-borne chemical pollutants\nare favored to partition onto suspended particulates, pollutant pathways are\nlikely to vary with the particle pathways. Study of pollutant dispersal into\nthe marine environment thus becomes very much a study of particlerpollutant\ndynamics on river deltas. Furthermore, when massive sediment deposition\noccurs on a river delta, anthropogenic inputs may be obscured and diluted to\ninnocuous levels. If these sediment pollutants are not reintroduced into the\nwater column by chemical, physical, or biological processes prior to \"deep\"\n69","burial, then delta sediment depositories become permanent reservoirs for enorm-\nous annual burdens of industrial and municipal wastes.\nAccomplishments FY 1985\nFISHERIES OCEANOGRAPHY\nCatch data from Japanese longline bluefin tuna fishing in the Gulf of\nMexico during 1979-1980 were analyzed relative to in-situ oceanographic data\nand satellite remote-sensing data. A threefold increase of catch per unit\neffort in 1980 compared with 1979 appears to be associated with the area\nfished, and seems to reflect a change in fishing strategy. The higher catches\nwere made primarily in proximity to the surface thermal front of the Gulf Loop\nCurrent. Correlations with other environmental factors such as sea surface\ntemperature, temperature differences, and current patterns, and with age of\nthe fish, were generally inconclusive.\nFISHERIES OCEANOGRAPHY COOPERATIVE INVESTIGATION (FOCI)\nFor the past several years, AOML has conducted research in cooperation\nwith the National Marine Fisheries Service with the long-term goal of under-\nstanding direct and indirect environmental controls on the year class strength\nof commercial fisheries. Research cruises with this specific objective have\nbeen conducted aboard the F/V Oregon II and the R/V Researcher in the Northern\nGulf of Mexico, particularly in and near the frontal plume of the Mississippi\nRiver. In this last year, a series of publications and presentations result-\ned, detailing the relationship between larval fish growth and abundance and\nthe concentration of their planktonic food resource by physical process. Pre-\nparatory to renewed field studies extending this work to new areas and fish\nspecies, a project was initiated through CIMAS to improve sampling technology\nin regard to synopticity, real-time feedback, and the integration of physical\nand biological sampling. AOML investigators led a team of ONR-funded univers-\nity investigators in a physical/biological study of the Gulf Stream core and\nwestern wall. Systems developed previously were substantially re-engineered\nfor this effort, particularly in regard to the incorporation of fluorescence\nsensors and computer interfacing capability. For the first time, zooplankton\ndata were gathered by traditional, acoustic, and optical methods in conjunc-\ntion with continuous acoustic records of current shear.\nTAP\nAOML continued studies of the mechanisms of metal/organic interactions in\nseawater, especially metal chelation by naturally occurring organic ligands.\nThe objective was to develop interactive biological/chemical models of metal\nspeciation as it affects ocean planktonic populations that serve as food\nsources to larval fish. Results of the work include the following:\nZooplankton samples collected in the northern Gulf of Mexico were\nanalyzed for species composition in areas where AOML has characterized\nthe chelation capacity of near-surface seawater.\n70","Chemical analyses showed that some marine organics can chelate metals\nstrongly enough to compete with artificial chelators, thereby impacting\nSO called \"total\" metal determinations.\nThe above discovery on chelation suggests that models of the thermody-\nnamic equilibrium speciation of a trace metal important in biological process-\nes may, therefore, incorrectly assess the potential impact of the introduction\nof a trace metal contaminant to an ecosystem. These results suggest that\nfuture work in the field must assess such an impact, in order to correctly\nmodel this process, through a thorough evaluation of the stability constants\nof naturally occurring organic ligands with metals.\nP-PRIME\nThe P-PRIME (Pollutant-Particle Relationships in the Marine Environment )\nprogram was completed in FY 1985 with publication of the following informa-\ntion:\nP-PRIME data from the Mississippi River and adjacent shelf (tables and\nillustrations detailing station locations, summaries of data types and\namounts thereof including dates of collection and geographical position,\ndepth, etc., suspended particulate matter size distributions, concentra-\ntions and trace metal analysis results).\nCompelling evidence that over the last decade a measurable decline in\nlead transport and deposition in and around the Mississippi River and\nDelta is related and proportional to the decreased consumption of lead in\nthe United States resulting from environmental regulations such as the\ndeleading of gasoline.\nPlans FY 1986\nFISHERIES OCEANOGRAPHY\nAOML\nContinuing work will require identification of new funding.\nFISHERIES OCEANOGRAPHY COOPERATIVE INVESTIGATION (FOCI)\nData analysis will occupy much of FY 1986. Publications will continue to\nresult from the Gulf of Mexico data, albeit at a reduced rate. The results of\nthe sampling technology cruise will have to be assimilated so that they may be\ntaken into consideration in designing the new field studies. Two separate\nfield studies are being planned in cooperation with the National Marine\nFisheries Service. The first will be aboard the F/V Oregon II in February\n1986, in collaboration with the Beaufort Laboratory of the Southeast Fisheries\nCenter. The second will be in the Shelikof Straits in May 1987, in collabor-\nation with PMEL and the Northwest and Alaska Fisheries Center.\n71","TAP\nNo additional activity is anticipated in this program unless new funding\nis identified.\nP-PRIME\nNo additional activity is anticipated in this program unless new funding\nis identified.\n72","PACIFIC MARINE ENVIRONMENTALLABOR\nEddie Bernard\nSeattle, Washington\nDirector\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nESG\nSTORM\nTOGA\nCRP WRP PROFS WMP\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nWPL\nARL\nAL\nSEL\nThe Pacific Marine Environmental Laboratory (PMEL) is a mission-oriented\ngovernment laboratory that conducts interdisciplinary scientific investiga-\ntions in oceanography, marine meteorology, and related subjects. The current\nPMEL programs focus on climate, marine environmental assessment, marine obser-\nvation and prediction, and marine resources. Studies are conducted to better\nunderstand the complex physical and geochemical processes that determine the\nextent of human impact on the marine environment; to define the forcing func-\ntions and the processes driving ocean circulation and the global climate sys-\ntem; and to improve environmental forecasting capabilities and other support-\ning services for marine commerce and fisheries. Products of PMEL's research\nare environmental information and predictive models that are disseminated by\nmeans of scientific papers, technical reports, and presentations at scientific\nand public gatherings.\nPMEL\nTwo cooperative institutes, the Joint Institute for the Study of the\nAtmosphere and Ocean (JISAO) and the Joint Institute for Marine and Atmos-\npheric Research (JIMAR), established between NOAA and the Universities of\nWashington and Hawaii, respectively, provide a bridge between the academic\ncommunity and PMEL scientists working in climate dynamics, environmental chem-\nistry, tsunami propagation, and estuarine processes.\nCLIMATE RESEARCH\nDuring recent years there has been an increasing awareness of the impact\nof short- and long-term climatic changes on resource systems, particularly\nfood and energy, and conversely, a concern about the impact of technology and\npopulation growth on world climate. When the National Climate Program Act was\npassed in 1978, NOAA became the lead agency for U.S. research in climate dynam-\n73","ics. PMEL scientists have been heavily involved in the formulation and imple-\nmentation of the NOAA Ocean Climate Program.\nTo predict climatic change, it is necessary to understand the processes\nof heat, moisture, and momentum exchange between the ocean and atmosphere, as\nwell as the large-scale transport of heat by the atmosphere and ocean. The\nocean climate research program investigates the problem in studies of both\nlocal (small-scale) and basin-wide (large-scale) ocean dynamics and the\ncoupled ocean-atmosphere circulation. Laboratory participation in multi-in-\nstitutional field experiments has established the groundwork for present\nefforts in two national climate programs: Equatorial Pacific Ocean Climate\nStudies (EPOCS) and Tropical Oceans and Global Atmosphere (TOGA). These\nstudies are testing the hypothesis that ocean surface temperature anomalies in\nequatorial regions have a pronounced effect on atmospheric circulation in both\nequatorial and temperate latitudes. A major research goal is to determine the\nrelative importance of the physical mechanisms that generate anomalies in sea\nsurface temperature distributions in the equatorial ocean.\nHeat transport by major western boundary currents, the Gulf Stream and\nKuroshio in the Northern Hemisphere, is also postulated to have an important\neffect on world climate. Studies at PMEL continue to focus on the Florida\nCurrent as part of the Subtropical Atlantic Climate Studies (STACS).\nPMEL also conducts two unique marine-chemistry research activities for\nNOAA under the National Climate Program. These activities relate to the\nocean's behavior as a sink for atmospheric carbon dioxide, which has been\nsteadily increasing over the past century. One project measures the flux of\nanthropogenic fluorocarbons into the ocean in order to trace gaseous diffusion\nacross the ocean-atmosphere boundary. The other project is examining the role\nof biologically produced, particulate calcium carbonate as an absorber of car-\nbon dioxide at high latitudes. Together these studies will help determine the\npotential of the oceans for absorbing carbon dioxide.\nAccomplishments FY 1985\nEQUATORIAL DYNAMICS\nEl Nino/Southern Oscillation (ENSO)\nDuring certain years, large interannual changes occur in the heat content\nof the upper layer of the tropical Pacific. Associated with these oceanic\nchanges (anomalies of 2° to 5°C in sea-surface temperature are observed) are\nperturbations in the atmospheric circulation that appear to initiate the ocean\nchanges. After the near-surface heat content of the ocean is modified, fur-\nther atmospheric perturbations are generated by process of air interaction\nwith the ocean. The phenomenon of mutual interaction of the tropical ocean\nwith the global atmosphere on interannual time scales has been termed the El\nNino/Southern Oscillation (ENSO) problem, and is the main focus of the NOAA-\nsponsored EPOCS program.\nResearch at PMEL on the ENSO problem is coordinated through the EPOCS\nprogram. During the past year our field program continued deep sea current\n74","moorings; measurements of wind, current, and temperature at the Equator in the\neastern Pacific; north-south transequatorial sections to measure velocity,\ntemperature, salinity, and dissolved oxygen across the major components of the\ncurrent system in the eastern Pacific; and time series of sea level at the\nGalapagos Islands. Ship-of-opportunity subsurface and surface temperature\ndata were analyzed. A numerical modeling program was begun during FY 1985,\nwhich focuses on increasing our understanding of the dynamical processes re-\nsponsible for changing the heat content of the tropical Pacific.\nEquatorial Dynamics During 1982-83 ENSO Event\nDuring the El Niño of 1982-83 there were large changes in the north-south\ndistribution of the depth of the thermocline as well as changes in the tempera-\nture of the surface layer. These changes imply significant changes in the\nstrength of the zonal current systems. During 1979-81, there was a decrease\nin the transport of the North Equatorial Countercurrent (NECC) in the northern\nsummer. In 1982 the transport of the NECC increased in the summer to a strong\npeak in November 1982. This peak was followed by very low values the follow-\ning summer. These variations were due primarily to shifts in the thermocline\ndepth; a shallower than normal thermocline at 10°N combined with a deeper\nthermocline at the Equator, creating a strong downslope to the south and a\nhigh transport. The very strong NECC eastward transport in the latter part of\n1982 contributed substantially to the accumulation of warm surface water in\nthe eastern Pacific that occurred at the end of 1982. In the period before\nthe 1982-83 event, the South Equatorial Countercurrent (SECC) transport typic-\nally increased in the first part of the year, while the NECC transport decreas-\ned. In 1982 the SECC transport peak did not develop, but it was present in\n1983. Studies of the seasonal cycle of the SECC transport have shown that it\nis primarily a response to the variation in the north-south gradient of wind\nstress. The 1982 SECC transport perturbation presumably is due to the change\nin the Southern Hemisphere wind stress pattern, which preceded the marked\nchanges that occurred in the summer north of the Equator in the central\nPacific.\nLong-time series of current mooring data in the eastern equatorial\nPacific were examined to delineate the seasonal cycle of the upper ocean's\ncirculation. To define the normal conditions that serve as background for El\nPMEL\nNiño anomalies, analysis was restricted to non-El Niño time periods. During\nthe northern spring. the South Equatorial Current (SEC) is replaced by east-\nward flow near the surface between 95° and 150°W in response to the annual\nweakening of the trade winds at the Equator. The intensity of the near-sur-\nface flow lags the climatical surface winds, but has the same westward propaga-\ntion observed in the wind field. The dominant features of the non-El Niño\nannual cycle have been reproduced by a three-dimensional linear model of the\nequatorial Pacific forced by the annual component of the climatological winds.\nIn October 1982 near the onset of the ENSO event, a two-ship survey in\nthe eastern Pacific was used to study water mass characteristics and circula-\ntion in the 10° square centered near the Gálapagos Islands. Sea surface tem-\nperature during this period was 3°-5°C above normal, and Galápagos sea level\nwas about 30 cm above normal. Surface temperature showed no indication of the\nGalápagos Front, which is usually pronounced this time of year. However,\nsince the Front was still present in surface salinity, southward advection of\n75","warm water across the Front was ruled out as a mechanism for producing the\nanomalously warm water. Rather, zonal advection appeared to be the dominant\ncause. Estimates of warm water transport in the study region showed an influx\nof about 21 X 106 across 95°W. Eastward near-surface flow was found all\nalong this section except for a narrow band just north of the Equator. Water\nmass characteristics indicated that flow in this band represented a return of\nNECC water rather than Equatorial Undercurrent (EUC) water. Along the north-\nern and southern boundaries of the study area, relatively weak poleward flow\nof the warm water layer was observed. The net outflow along these boundaries\nwas only about 6 X 106 Thus, about 15 X 106 m3 appears to be con-\ntinuing eastward across 85 °W and must either escape in a narrow coastal cur-\nrent along South America or accumulate in this eastern region. Little evi-\ndence for the former is seen in coastal sections taken in December. Assuming\nthe latter leads to a predicted sea level rise of about 0.5 cm d-1, an amount\nclose to the observed rate of sea level increase at the Galápagos from\nSeptember to December. This result suggests that zonal advection of warm sur-\nface water from the west is the dominant mechanism leading to the initial\nwarming in the eastern Pacific.\nStudies such as the one discussed above are hampered by the lack of con-\ntinuous records of upper ocean thermal structure. In addition, such measure-\nments are required in order to monitor the ocean variability and, in the\nfuture, assess the likelihood of subsequent El Niños. To provide such informa-\ntion in real time, PMEL has developed the ATLAS (Automated Temperature Line\nAcquisition System) moored thermistor chain, which telemeters, via satellite,\ntemperatures to a maximum depth of 500 m. Time series data from an ATLAS\nmooring, deployed at 2°S, 110° since December 1984, have shown the seasonal\ncycle of warming during spring and cooling during summer of 1985. The warming\nis confined to the upper 50 m; there is little participation by the thermo-\ncline. Such a record demonstrates the importance of local heating in generat-\ning the seasonal temperature variability. Measurements from ATLAS moorings at\n165°E, 140°W, and 110°W will be used to monitor the thermal variability in\nreal time.\nThe velocity structure of the equatorial Pacific has been studied using\nNOAA vessels equipped with acoustic Doppler current profilers. The data are\ncollected while the ship is underway, providing continuous and spatially high-\nresolution ocean velocity sections. The variations in these velocity sections\nbeing analyzed in terms of the effect on the heat content of the upper\nare\nocean in the tropical Pacific.\nRadiant Heating of a Wind-Roughened Sea\nIn a general circulation model of the coupled atmosphere-ocean climate\nsystem, the heating terms describing the conversion of solar radiant energy\ninto potential thermal energy drive the motions of the system. In the ocean\npart of the model, the albedo of the air-water surface is a key factor for\ndefining the heating rate in the upper ocean layer. By combining physical\noptics and water wave statistics the dependencies of the albedo, over the visi-\nble electromagnetic spectrum, on various wind speeds, wind directions, and\nsolar altitudes have been found. In general, the radiant flux across the air-\nwater interface increases with increasing wind speed. Both theory and experi-\n76","ment show that capillary waves, rather than gravity waves, are the dominant\ndeterminants of the sea surface's albedo.\nTropical Modeling and Analysis Program\nThe Tropical Modeling and Analysis Program (TMAP) was established to add\na theoretical and numerical modeling balance to PMEL's climate observational\nprogram. Procurement of the needed computer hardware and hiring and training\nof staff was a major part of this effort during FY 1985. Model studies of\nENSO phenomena were begun through analysis of a hindcast of the 1982-83 ENSO\nevent done at GFDL. Attention was focused on the evolution of surface cur-\nrents and sea-surface temperature (SST). During the initial phase of the\nevent, when central Pacific equatorial SST warmed rapidly, the model hindcast\nindicated that anomalous zonal advection of heat from the west was the primary\nwarming mechanism. Later in the event the processes are more complex.\nSTACS\nMeasurements of voltage differences using submarine cables have been\nshown to be valuable for continuously recording the transport variations of\nocean currents such as the Florida Current. In addition to cable voltages\ninduced by ocean currents, there are voltages induced by time-varying ionos-\npheric and magnetospheric electric currents. Robust methods have been develop-\ned whereby the geomagnetic variations can be removed by using magnetic data\nobtained at remote magnetic observatories and therefore free of ocean-induced\nvariations. This method has been used to correct voltages from a cable spann-\ning the Florida Straits between Jupiter Inlet, Fla., and Settlement Point,\nGrand Bahama Island. The geomagnetically induced voltages in submarine cable\ndata can be reduced by using shore-based magnetic data even if the shore site\nis remote, since geomagnetic variations are coherent over global scales. This\ndata processing technique has also been applied to magnetotelluric survey data\nwhere it has proved to be very effective in removing noisy values and yielding\nsuperior response estimates to the commonly obtained band-averaged estimates.\nIn order to expand the cable measurement program, 140 days of hourly mean\nPMEL\ncable voltages from the telephone cable that spans the Florida Straits between\nWest Palm Beach, Fla., and Eight Mile Rock, Grand Bahama Island (about 20 mi\nsouth of Jupiter) were collected with the cooperation of AT & T. These cable\nvoltages represent the voltage difference between the sea-water contacts at\nWest Palm Beach and Eight Mile Rock and can be corrected for fluctuations in\nthe cable power supply since the power supply electric current was also measur-\ned. Measurements of temperature at the power station and a comparison with\nthe Jupiter Inlet/Settlement Point cable voltages established that the power\nseparation filter has a temperature-induced variation, and a temperature co-\nefficient approximately that of copper.\nCARBON DIOXIDE/RITS RESEARCH\nSince about 1850, human activities, including the burning of fossil fuels\nand deforestation, have raised the atmospheric carbon dioxide (CO2) level from\nabout 280 ppm to 345 ppm in 1985. This CO 2 increase is thought to affect the\n77","Earth's radiation balance, leading to an increase in the Earth's temperature.\nMajor repositories for fossil-fuel-derived CO2 are terrestrial vegetation, the\natmosphere, and the oceans; each of the last two contains close to 50% of the\nexcess according to recent estimates. The buildup rate of atmospheric CO2\ndepends on the oceanic uptake rate of CO2, which is controlled by diffusive\nand convective mixing processes, by sinking and decomposition of biogenic par-\nticulates, and by air-sea exchange rates.\nBecause the oceans act both as a source and as a sink for atmospheric\nCO2, 2 , particularly in upwelling and downwelling areas, PMEL scientists contin-\nued an interdisciplinary study of the CO 2 system in the surface and intermedi-\nate waters of the eastern North Pacific during the summer and winter of FY\n1985. The purpose of these investigations was to study the dynamics of the\nCO 2 system and gas exchange along a meridional transect that includes major\nfrontal systems in the North Pacific.\nDuring February and July 1985, on two cruises in the eastern North\nPacific, measurements were made of total CO pCO2 alkalinity, freons, sus-\npended matter, calcium, salinity, temperature, oxygen, and nutrients. In\naddition, atmospheric and surface ocean measurements of CO2 and CH4 were made\nin cooperation with scientists from ARL's Geophysical Monitoring for Climatic\nChange (GMCC) Division. The preliminary data for July indicated significant\nvariations of seawater pCO 2 concentrations along the transect, with near-satur-\nation values near the Subpolar Front, and supersaturated values in the Sub-\npolar Gyre. The winter values were significantly lower than the summer values.\nThe high values in the Subpolar Gyre are probably due to seasonal heating of\nthe surface waters. These results suggest that the waters near the Subpolar\nFront are sinking faster than the time required for equilibration with respect\nto CO 2 or significant uptake by marine phytoplankton.\nThe fluorocarbon tracers F-11 and F-12 were also measured on both the\nwinter and summer cruises. The F-11 distribution for the summer cruise\nrevealed maxima in the mixed layer in the Gulf of Alaska near station \"P\",\nslightly above saturation equilibrium with respect to the overlying atmos-\npheric burden (as observed for CO 2 as a result of seasonal heating). A subsur-\nface freon maximum was traceable southward across the Subpolar Front and Sub-\ntropical Gyre nearly to Hawaii. The fluorocarbon signal was detectable to a\nleast 800 m at 35°-40°N, the deepest penetration along the section. A compari-\nson with previous F-11 profiles taken near \"P\" in December of 1980 reveals\nthat the near- surface freon concentration has risen in direct proportion to\nthe 20% atmospheric increase during this 41/2-year interval. However, below the\nmixed layer the F-11 burden within the upper thermocline ( OT = 26.5-27.0) has\nat least doubled since 1980. Although a gradual deepening of tracer profile\nwas to be expected as a result of the slower rate of atmospheric increase\nsince the late 1970's, the very rapid fluorocarbon accumulation suggests that\nthis period (1980-85) has been one of unusually efficient thermocline ventila-\ntion. Local vertical overturning and/or lateral advection from source regions\nto the west are the major ventilation mechanisms, but whether the observed\nincrease in freon in the thermocline has been gradual or the result of a par-\nticular overturning event cannot be determined from the limited sampling.\n78","Plans FY 1986\nEQUATORIAL DYNAMICS\nImplement an array of 12 ATLAS thermistor chains spanning the equatorial\nPacific from 165°E to 110°W. The data obtained will be used to provide\nreal-time information on thermal structure variability and to study the\nlow-frequency variability.\nUse the ship-of-opportunity thermal data set to assess the role of\nvariations in wind forcing in changing the thermal field; carry out\nnumerical model verification studies with the data.\nComplete tropical Pacific island surface wind analyses and prepare\nresults for publication.\nConduct a variety of hindcast studies of the 1982-83 ENSO event, using\nthe GFDL model and surface wind stress fields prepared by different\ngroups, and determine the model mechanisms responsible for the evolution\nof near-surface currents and SST. Compare model results with ocean data\nas possible.\nStudy the prediction of El Niño and related global atmospheric events,\nusing a new statistical technique based on the discriminant method.\nSTACS\nInvestigate the upstream variations of the Florida Current and the origin\nof the occasionally large monthly transport bursts by expanding the cable\nvoltage recording system to include telephone cables between Key West,\nFla. , and Havana, Cuba, and between St. Thomas, Virgin Islands, and\nMaiguetia, Venezuela, and compare the voltages with those being collected\nfrom the Jupiter Inlet/Settlement Point cable.\nCARBON DIOXIDE/RITS RESEARCH\nPMEL\nContinue North Pacific time series of fossil CO, 2 increase.\nBegin measurements of radiatively important trace species (RITS) in the\nNorth Pacific.\nDevelop kitetoon atmospheric boundary layer sampling capability.\nMARINE ENVIRONMENTAL ASSESSMENT\nMarine environmental assessment at PMEL emphasizes understanding the com-\nplex physical and geochemical processes that ultimately determine the health\nof the marine system and its ability to assimilate pollutants. Included in\nthis area are studies of suspended-sediment transport and geochemistry, distri-\nbutions of hydrocarbons and synthetic organics, coastal and estuarine circula-\ntion, theoretical modeling of pollutant transport processes, and a program in\n79","marine sources of acid rain. Although the geographic focus of these studies\nhas been Pacific Northwest and Alaskan coastal and estuarine waters, the scien\"\ntific knowledge acquired and methodologies developed are applicable to other\nmarine systems. Two major activities at PMEL are studies of the long-range\nfate of chronic pollutants in marine waters and oceanic precursors to acid\nrain.\nAccomplishments FY 1985\nLONG-RANGE-EFFECTS RESEARCH\nIn response to the Marine Protection, Research and Sanctuaries Act of\n1982 and the National Ocean Pollution Research and Development and Monitoring\nPlanning Act of 1978, PMEL has addressed environmental concerns associated\nwith transport and marine disposal of municipal waste water and the reaction\nof marine systems to continuous influx of pollutants. Under the NOAA Long\nRange-Effects Research Program (L-RERP), PMEL is examining the role of suspend-\ned particulates in transporting pollutants or in removing them from the marine\nsystem. In support of these studies researchers are investigating the mechan-\nisms by which heavy metals and organic pollutants adhere to particulates. As\nthese processes become better understood we will be able to assess the long-\nterm effect of chronic, low-level input of pollutants into the marine system.\nStudies in the Puget Sound-Strait of Juan de Fuca system, under way for\nseveral years, are leading to a better understanding of Puget Sound's ability\nto accommodate pollutant inputs. Many pollutants adhere to and move with par-\nticles, and ultimately are buried in the sound or transported out of the sound\nalong with particles. The emphasis of much PMEL research, therefore, has been\nparticle transport and fate.\nPollutant Transport in the Water Column\nPollutants are derived from both natural and human sources, including\nriverine, atmospheric, municipal and industrial sewage discharge, and dredging\noperations. Mass balance calculations for many pollutants indicate that human\nsources exceed the natural sources, and buildup in sediments occurs over decad-\nal or longer time scales. The assimilative capacity of an estuary is a func-\ntion of the individual pollutant's physiological effects on the indigenous\nmarine life, residence time in the estuary, biological availability and up-\ntake, and the physical and chemical transformations occurring in the water\ncolumn and in the sediments.\nDuring FY 1985, PMEL scientists continued to make significant advances in\nour understanding of the physical and chemical processes controlling the dis-\ntribution and fates of toxic trace metals and hydrocarbons in coastal areas\nand estuaries. Following are descriptions of accomplishments in related theo-\nretical, observational, and modeling research efforts.\nTheoretical work on modeling the long-term, two-layer circulation in\nfjords uses freshwater and salt as convenient tracers to deduce the recircula-\ntion, or refluxing, of water between outflowing and inflowing layers at mixing\n80","zones where fjord reaches intersect. However, if such an intersection in-\nvolves more than two reaches, more tracers are necessary to resolve the mathe-\nmatical indeterminacy. Unfortunately, long-term data sets for other tracers\nare not usually available. Therefore, a technique based upon entropy maximiza-\ntion has been developed to yield a solution that is maximally noncommittal\nwith regard to the missing tracer information. An application to Puget Sound\nindicated that less than 1/2 of the seaward-flowing surface water is recircu-\nlated landward because of mixing at the Admiralty Inlet sill; this is somewhat\nlower than earlier estimates of 2/3. Dissolved copper concentrations were\nused in conjunction with the refluxing model to both test and improve it.\nGiven estimates of copper inputs to Puget Sound, the model predicts copper\nconcentrations, which in turn have been compared with actual observations.\nTheory and observation show similar trends and agree to within error limits.\nAn advantage of the maximum entropy technique is that new tracer information\ncan be incorporated readily to produce improved reflux coefficients. The\nmodel has been run with and without anthropogenic inputs to evaluate the\neffect of human activities on Puget Sound copper concentrations.\nA theoretical index based on the estuarine Richardson number was devel-\noped to predict the occurrence and intensity of intrusions of new water into\nestuaries controlled by sills. For Puget Sound this index was computed from\npredicted tidal currents in Admiralty Inlet for the period 1970-1989. It\nshows that the strongest intrusions should occur during 4-month periods\ncentered on the spring and fall equinoxes with gaps during the winter and\nsummer solstice periods. An apparent 4-5 year cycle in the intrusion index is\nbeing compared with observations.\nAcoustic observations are being used to deduce the degree of mixing\nduring the onset of intrusions. Once initiated, dense bottom water propagates\n70 km up-estuary, replacing water existing below the 65-m sill. Five episodes\nof deep-water renewal were observed at approximately fortnightly intervals in\nresponse to enhanced gravitational circulation and reduced turbulent mixing\nduring neap tides over the entrance sill. At mooring sites along the estuary,\nrenewals were characterized by a sequence in which there occurred a rapid\nchange in temperature followed by a 2-10 day up-estuary pulse of deep currents\nand maxima in salinity and density. The renewal characteristics were phase\nlagged with distance from the sill; this lag indicated up-estuary velocities\nPMEL\nof 7-14 cm s-1. The observations of the advance and vertical structure of the\ndeep intruding water are interpreted as a turbulent gravity current that\nspreads linearly with a constant mean velocity and a density difference that\nvaries inversely with distance due to entrainment. A classical two-layer box\nmodel used to estimate flow during various stratification and runoff condi-\ntions indicated a possible seasonal cycle in transport with a maximum in\nwinter and a minimum in summer. Evaluation of long-term observations of flow\nat one location are now beginning to confirm the predictions. Transports in\nJanuary-March are about double those in June-August. The exact monthly inter-\nvals, however, would vary for any particular year. Thus, replacement rates\nfor water will obviously vary throughout the year, and incorporation of these\nideas with the intrusion index concept is under way. Observations across the\nsection of the long-term measurements are being used to improve calibration of\ntransport estimates.\nInvestigations are also continuing on the vertical transport of particles\nand pollutants through the water column. Because of the uncertainties regard-\n81","ing sediment trap efficiency in estuarine environments where current flow may\nexceed 100 cm s-1, a field experiment was designed to compare the trapping\ncharacteristics of drifting traps and moored traps. A special trap that\ndivides the vertical flux into four discrete samples representing different\nflow regimes was designed and built. Results of the experiment showed that\ncylindrical sediment traps are efficient collectors of the \"true\" vertical\nflux (as measured by drifting traps that sense no relative flow) at\ncurrent\nspeeds up to approximately 100 cm s-1. Total flux varied by 10% between drift-\ning and moored traps. More importantly, the particle population, as defined\nby size and density distributions, was the same for drifting and moored traps.\nThis latter result held even during intervals of much higher current speeds\nwhen moored traps under-sample the total flux. The success of this field ex-\nperiment indicates that the vertical particle transport can be measured\naccurately under most estuarine flow regimes.\nSediment trap investigations have also been valuable in quantifying the\ntransport and fate of toxic metals in Puget Sound. Comparisons of metals in\nsediment trap particulates and metals in sediments indicate that for many\nmetals, including Fe, Cr, Ni, Zn, and Pb, retention in estuarine waters is\nenhanced by scavenging processes in the water column. Only a small fraction\nof the total metal flux is recycled at the sediment-seawater interface and,\nconsequently, most of the toxic metals are retained within the fine-grained\nsediments of Puget Sound. Trace metals that are rapidly scavenged by particu-\nlates are subsequently enriched in the surface layer of the sediments.\nPolycyclic aromatic hydrocarbons (PAH) are toxic hydrophobic compounds\nand are also generally associated with particulates. Particulate hydrocarbon\nconcentrations in the main basin of Puget Sound decrease with depth in the\nwater column and with distance from Seattle. The residence time of these pol-\nlutants in the water column is not sufficient for mixing to take place through-\nout the estuary or out of the estuary. Although these compounds are rapidly\ntransported to the bottom sediments, resuspension and lateral transport in the\nbottom nepheloid layer disperse the compounds throughout the fine-grained sedi-\nments in the center basin.\nDuring the past year, PMEL also began, for EPA, multidisciplinary field\nstudies of pollutant transport in the two main urbanized embayments of Puget\nSound, Elliott Bay, and Commencement Bay. Earlier PMEL studies of transport\nprocesses in Elliott Bay had shown that pollutant-bearing particles are added\nto the surface waters by river inflow, combined sewer outfalls, atmospheric\nprecipitation, and other routes. Those particles that remain suspended above\nthe pycnocline are advected out of the bay by the estuarine circulation. Part-\nicles that rapidly settle out of the surface layer contribute to pollutant\naccumulation in the bottom sediments. Bottom sediments may be a new sink for\nparticles rather than a source to the main basin.\nBottom Boundary Layer Processes\nIn the bottom boundary layer, active processes determine much of the\ntransport and deposition of sediment and particulate-borne pollutants. Tidal\nand other currents resuspend material from the bottom; the material is then\ndiffused upward by turbulence into the overlying water. There, this material\nreacts with dissolved and suspended chemical constituents before settling back\n82","to the bottom. Entering the layer from above and upstream are new sediment\nand dissolved constituents. Manganese and iron ion particles, for example,\nscavenge toxic metals from the water column and carry them down to the bottom\nsediment. Some of the manganese and iron are chemically reduced in bottom\nsediment and diffuse back into the water column. Boundary layer processes\nhelp determine the extent and duration of the exposure of biota to pollutants\non and near the bottom.\nA boundary layer model using turbulence closure was implemented to simu-\nlate chemical, sediment, and flow processes near the bottoms of estuaries.\nObtained from the Swedish Meteorological and Hydrological Institute, this\nmodel supplements the high-resolution boundary layer models that have been\ndeveloped at PMEL. One result of the investigations was the finding of undul-\nating patterns in the eddy viscosity profiles, due to tidal currents. The\neffects of the undulating pattern on sediment and trace metal processes are\nnow being studied. The distributions of dissolved and particulate manganese\nare found to be strong functions of the time constants for chemical reactions\nrelative to the time scales of diffusion and tidal currents. The model played\na central role in the planning of a near=bottom experiment in Puget Sound that\nwas carried out in FY 1985.\nOne focus of the L-RERP sediment transport work has been on erosion\nrates, their characterization and prediction. A critical review of the litera-\nture and a match of a high-resolution model to laboratory observations indi-\ncated that erosion of abiotic, fine sediment occurs at bottom stresses well\nbelow those often cited as critical stresses. This can be seen from a\nstatistical point of view in which the turbulent currents produce random con-\ncentrations of stress over a bed of particles with randomly varying exposures\nto the flow. This line of research is continuing through intensive modeling\nand field experiments. A two-dimensional model under development will simu-\nlate the erosion and transport of sediment down the major axis of Puget Sound.\nPollution Accumulation In Sediments\nRecent sedimentation in estuaries is of special interest because it is\none important way anthropogenic particulate-borne contaminants are isolated\nfrom the estuarine biosphere. In the past year, work was completed on the\nPMEL\nanalysis and interpretation of 210-Pb data from cores taken along the axis of\nthe main basin of Puget Sound. The results suggest that a zone of rather high\ndeposition is off Elliott Bay. The results also show that biota within the\nupper part of the sediment column can be churning surface-deposited material\nto a depth of 35-40 cm. This rather rapid mixing helps bury newly deposited\ncontaminants, but it also exposes much older sediments and contaminants to the\nsediment-seawater interface.\nThe sediment column also provides a historical record of the usage of\nmaterials indicative of industrialization. The record is blurred by the\nstirring of sediments by the infauna but 210-Pb profile analysis allows us to\nquantify the pattern of mixing. Historical records of pollutant sources can\nthen be related to the pollutant profile of the sediment column. By using as\nsource history the sum of tetraethyl lead in the Puget Sound area and a steady\ncontribution from industrial sources that began in 1890, the profiles of\nstable Pb within the sediment column were determined. The result compares\n83","favorably with the measurements of stable Pb made on a core near Meadow Point,\nSeattle, for which coincident 210-Pb data were acquired. PAH profiles are\nbeing similarly compared.\nACID RAIN RESEARCH\nReduced sulfur compounds are produced biologically in the photic zone of\nthe ocean. Our initial studies showed that dimethylsulfide (DMS), the most\nabundant volatile sulfur compound in surface ocean waters, contributes signifi-\ncantly to the global atmospheric burden of sulfate. Our recent efforts have\nstressed the coastal ocean and its potential impact on regional sulfur budgets.\nRegional sulfur budgets are necessary to assess the relative importance of\nnatural and anthropogenic emissions on the chemistry of precipitation, since\nthe tropospheric residence time of sulfate is thought to be insufficient for\nthis species to be well mixed on a global or even hemispheric scale.\nDMS concentrations were measured in ocean waters along the West Coast of\nthe United States on four cruises from May 1983 to May 1985. Concentrations\nin surface waters ranged from 13 to 380 ng S L-1 with a summer average of 60\nand\na winter average of 20 ng S L-1. By use of the stagnant film boundary\nlayer model, the flux of sulfur from the ocean to the atmosphere was calculat-\ned to be 30 mg S m2 yr Based on average surface zonal wind velocities and\nan assumed non-sea-salt sulfate atmospheric residence time of 5 days, the calc-\nulated net flux of biogenic sulfur to the West Coast of the United States is\n0.05 Tg yr Because of the many assumptions, the net flux is known only\nwithin a factor of 2-3.\nThe depositional area for this marine sulfur is more difficult to esti-\nmate. The principal mechanism by which sulfur is removed from the atmosphere\nis cloud scavenging and precipitation. Much of the rainfall in the western\nUnited States occurs on the western slopes of the mountain ranges. We pose\ntwo continental regions of potential deposition for this oceanic sulfur, the\nregion west of the Cascade/Sierra Nevada Mountains and the region west of the\nRocky Mountains. The estimated oceanic biogenic sulfate is 13% of the anthro-\npogenic emissions in the first region and 4% in the second region. It is pos-\nsible that the oceanic sulfur is largely deposited in an even smaller region,\nsuch as the area west of the Olympic/Coastal mountain ranges.\nPlans FY 1986\nLONG-RANGE-EFFECTS RESEARCH\nComplete analysis of selected 1984 cores to determine the along-channel\nand cross-channel patterns of organic pollutant accumulations in Puget\nSound.\nContinue the development of one- and two-dimensional models of chemical,\nsediment, and flow processes in the bottom boundary layer.\nCarry out an experiment in Puget Sound to calibrate and test models of\nbottom boundary layer processes.\n84","Obtain reliable, first-order estimates of the relative scale of pollutant\ntransport paths (surface plume vs. bottom nepheloid layer) in Elliott\nBay.\nACID RAIN RESEARCH\nRefine flux estimates by measuring DMS and its precursors in the ocean\nand DMS and its oxidation products in the atmosphere.\nMARINE OBSERVATION AND PREDICTION\nMarine observation and prediction research is directed toward understand-\ning and improving the prediction of phenomena related to marine warning and\nforecasting services. Research subjects include sea-ice processes, hazardous\nwinds, hazardous waves, and tsunami propagation and run-up. PMEL scientists\nwork closely with colleagues from operational service components of NOAA, such\nas the Northwest Ocean Service Center and the Navy/NOAA Joint Ice Center.\nStudies of sea-ice processes are also applicable to NOAA's climate research.\nThese studies of coastal meteorology, physical oceanography, and searice pro-\ncesses are carried out through a combination of field measurements, remote-\nsensing techniques, and numerical modeling.\nAccomplishments FY 1985\nSEA ICE RESEARCH\nThe Arctic Polynya Experiment\nThe Arctic Polynya Experiment (APEX) was conducted in the vicinity of St.\nLawrence Island in the northern Bering Sea during the winter of 1984-85. The\npurpose was to investigate physical processes in the atmosphere, sea ice, and\nocean and to observe the interaction of a wind-driven polynya with regional\ndynamics and thermodynamics. The relative importance of baroclinic currents\nPMEL\ndue to brine rejection during the freezing of ice in the polynya, barotropic\ncurrents due to set-up on the shelf (particularly differences between the\nAnadyr Strait and Sphanberg Strait), internal ice stress due to presence of\nSt. Lawrence Island, wind stress, and Coriolis force on sea ice motion are\nbeing considered. The measurement program included a variety of field measure-\nments from ocean moorings, from the sea ice, and from St. Lawrence Island.\nNine ocean moorings, 15 Argos position buoys, 2 GOES shore meteorological\nstations, and 2 GOES ice stations were deployed in and around the Bering Sea.\nWeather conditions during January over the eastern Bering Sea and western\nAlaska were anomalous with the warmest air temperatures on record and the\nleast ice ever recorded for a January, both due to prolonged southerly winds\nthroughout the month. During the last three weeks in February, the winds\nshifted to northerly, air temperatures dropped, and the ice recovered its pre-\nvious minimum both by freezing in situ and by the return of Bering Sea ice\n85","from the Chukchi Sea. The Argos buoys initially drifted south-to-southwest-\nward. In February the buoys turned and drifted northward. This is consistent\nwith the idea that reversals in Anadyr Strait (periods of southward flow) are\nof shorter duration than in Sphanberg Strait, although this was certainly one\nof longest reversals ever observed for Anadyr Strait. The eastern array lost\ntwo Argos buoys on the southward transit past the island and one on the north-\nward transit from crushing or shear, and both arrays exhibited greater deforma-\ntion than the MIZEX-West array had while passing St. Matthew Island during\n1983. The buoys in the western array melted out at the ice edge between 18\nMarch and 2 April and in the eastern array between 17 May and 16 June.\nThe data from the over-winter current meter moorings, the arrays of drift-\ning ice buoys, and the regional meteorological stations should provide new\ninformation on high-latitude sea/ice/air interactions and contribute to our\nunderstanding of Arctic heat, salt, and ice budgets.\nVessel Icing\nAbility to forecast icing is one of the most important marine meteorolog-\nical problems in high-latitude waters because rapid accretion on superstruc-\nture creates an extreme hazard. Icing conditions require the presence of sub-\nfreezing air temperatures, strong winds, and sea surface temperatures not more\nthan 6° above freezing; thus, it is not always obvious which way a vessel\nshould head to mitigate a situation. Actual icing rate is a characteristic of\neach vessel, depending on its design and sea-keeping ability.\nDuring FY 1985 a categorical algorithm was completed that related vessel\nicing to meteorological parameters. An initial set of 195 icing incidents\nfrom Alaskan waters during 1980-1983 was reduced to a data set of 85 observa-\ntions verified by interviews with the observers. Meteorological information\nin these reports was compared for consistency with the Anchorage Weather Ser-\nvice Forecast Office meteorological analyses. Fifteen icing rates were\ngreater than 2.0 cm h=1, substantially higher than those in the Alaskan obser-\nvation base available for our previous icing rate nomogram.\nA major feature of the algorithm development is the use of a robust sta-\ntistical procedure to relate icing rates to meteorological parameters. The\nmethod is considered robust because the influence of inaccuracies in any indi-\nvidual observation in the data set is minimized by basing the algorithm upon\nicing and predictor categories. This contrasts with standard regression tech-\nniques in which extreme observations either have undue weight or are excluded\nfrom the data set as outlying values.\nThe new algorithm predicts icing rates greater than three times those of\nthe previous NOAA nomogram. The new results will be incorporated in National\nWeather Service guidance products issued from the Marine Products Branch of\nthe National Meteorological Center, and the Alaskan Region.\nHAZARDOUS WAVES\nOn October 12, 1984, during a flight of the U.S. Space Shuttle Challenger\nthe Shuttle Imaging Radar-B (SIR-B) system acquired imagery of the ocean sur-\n86","face near Hurricane Josephine, which had a peak maximum sustained wind speed\nof approximately 90 kn. Such wave data--large-scale, synoptic, directional,\nand near a hurricane--are rare. Imagery, taken over a period of about 2.5\nmin, covered an area 25 km wide by 600 km long and had a resolution of about\n33 m. Surface wave patterns were clearly evident. Sub-areas of the imagery\nwere subjected to two-dimensional fast Fourier transform analysis, from which\nestimates of the dominant wavenumber vectors could be derived. A primary wave\nsystem was evident that moved away from the storm track and was distinguished\nby a smooth and continuous variation in wavelength and direction along the\nentire 600 km length of the radar swath. The system underwent a 90° rotation\nin direction. and displayed a decrease in wavelength of more than 30% from\n>300 m to <200 m. Also evident were secondary systems that displayed consider-\nable variation in wavelength and direction.\nTSUNAMIS\nThe Agency for International Development (AID) awarded PMEL a contract\nfor a project titled THRUST (Tsunami Hazard Reduction Using System Technology)\nTHRUST's purpose is to demonstrate the effectiveness of a regional early warn-\ning system for an underdeveloped country. The pilot project will take place\nin Chile. The major efforts this year were the development of a Pacific basin\ntsunami data base and the development of instrumentation for the THRUST system.\nThe system uses existing seismic instrumentation connected to satellite commun-\nication to establish a warning system. With this system, Chile will have\nrapid data acquisition and analysis, and quick information dissemination.\nTime series analyses were performed on data collected at six coastal tide\nstations during a low-amplitude, Pacific-wide tsunami that occurred on 3 March\n1985 just offshore of Valparaiso, Chile. All records were characterized by\nsignificant energy in the 50-60 min period band. Higher frequency energy,\nthough dominant at the two southernmost stations, decayed rapidly away from\nthe source in a northerly direction. Initially, low-frequency energy also\ndecayed northward. but then increased monotonically after reaching a minimum\nat Caldera.\nBottom pressure recorders were deployed in the equatorial Pacific to\nrecord the characteristics of passing tsunamis in the open ocean. Several\nPMEL\nsmall tsunamis have been recorded, as well as signals from distant storm\nevents.\nPlans FY 1986\nSEA ICE RESEARCH\nThe second phase of the APEX experiment ice buoy deployments will be\nconducted in the northern Bering Sea to study sea ice drift in the\nvicinity of Bering Strait, to provide a scientific basis for extending\nthe sea ice forecasting model to this region.\n87","A two-dimensional, coupled ice/water model for the Bering Strait region\nwill be developed as the first phase of a complete Bering/Chukchi ice\nforecasting model.\nHAZARDOUS WAVES\nFurther studies of the Challenger SIR-B imagery will focus on the\ndynamics of hurricane wave generation and propagation, and the influence\nof fundamental hurricane parameters such as the radius to maximum winds,\nthe maximum sustained wind speed, and the hurricane forward velocity.\nTSUNAMIS\nAdditional numerical simulations are planned of long-wave propagation\nalong the entire west coast of South America for a variety of tsunami-\ngenerating mechanisms. More detailed studies of the response of the\nValparaiso harbor to nearby sources will be carried out on a relatively\nfine-scale grid.\nMARINE RESOURCES\nHydrothermal venting, which occurs along seafloor-spreading centers,\nrepresents a basic input of heat and materials into the oceans. The effect of\nhydrothermal venting on the marine environment is the focus of PMEL's marine\nresources program called VENTS (not an acronym). Research efforts have been\nspecifically designed to define and quantify the chemical, geological, and\nphysical oceanographic processes evolving from the venting of hydrothermal\nfluids. Current studies of hydrothermal venting have focused on the Gorda and\nJuan de Fuca Ridges.\nIn PMEL's second major area of research in marine resources, fisheries\noceanography program development and preliminary field experimentation contin-\nued in anticipation of future funding of the Fisheries-Oceanography Coopera-\ntive Investigations (FOCI) initiative. FOCI, which combines the expertise of\nPMEL and of NOAA's Northwest and Alaska Fishery Center, has the primary re-\nsearch objective of understanding the influence of variability of North\nPacific meteorology and physical oceanography on commercially important\nfisheries.\nAccomplishments FY 1985\nVENTS PROGRAM\nVENTS conducts research on seafloor-spreading processes to assess the\nconsequences of high-temperature hydrothermal venting at geologically active\nridges. Hydrothermal venting systems are thought to have a significant effect\non the oceanic thermal and mass budgets. They are a major source for mineral-\nization of seafloor sediments and a primary source for the formation of a\nvariety of metallic sulfides. Further, the close association between active\n88","venting and characteristic vent communities constitutes an important element\nin NOAA's ongoing research in marine living resources.\nOne of the principal goals of VENTS is to quantify the effects of hydro-\nthermal venting on the biogeochemistry and physics of the oceans. Materials\nand heat hydrothermally cycled between the Earth's crust and seawater along\nmid-ocean-ridge spreading centers, at hot spots, and in back-arch basins are\nknown to play an important role in the global distributions of many elements.\nLocalized deposits resulting from hydrothermal venting may provide significant\nreserves of economically important metals. VENTS investigators examine the\ncomposition and flux of venting materials and study the biogeochemical and\nphysical processes that occur as these materials are mixed and dispersed by\ninduced and ambient ocean motion.\nDuring FY 1985, three major field experiments were conducted in support\nof VENTS: three Surveyor cruises to the Gorda and Juan de Fuca Ridges, a\nResearcher cruise to the Mid-Atlantic Ridge, and an Atlantis II/Alvin submers-\nible cruise to the Galápagos Ridge.\nOn the Gorda Ridge, hydrothermal indicators showed a strong along-strike\nvariation consistent with the known variation of spreading rates. Stations on\nthe slowly spreading (~1.5 cm yr-1) southern and central portions of the ridge\nexhibited no enrichment in dissolved or particulate hydrothermally derived\nmaterial. At the two most northerly stations, where the spreading rate is\n-5.5 cm yr plumes of almost certain hydrothermal origin were identified on\nthe basis of increased particle concentration anomalous hydrographic proper-\nties, and increases in dissolved and particulate trace metals. The plumes\nwere found between 2700 and 3000 m and were as much as 600 m above the floor\nof the axial valley, suggesting that the vent sources are located somewhere on\nthe adjacent valley walls as has been observed for the similar topography of\nthe Mid-Atlantic Ridge. The Gorda Ridge is the only known section of hydro-\nthermally active ridgecrest that lies within the Exclusive Economic Zone (EEZ)\nof the United States.\nHydrothermal plumes from three tectonically dissimilar regions of the\nJuan de Fuca Ridge were sampled from Surveyor in June to provide the first\ninternally consistent data representative of several different plume types.\nA\nmetal-dominated, high-exit-temperature plume was found over the southern Juan\nPMEL\nde Fuca Ridge whereas a sulfur-dominated plume was found above the Endeavour\nRidge segment of the northern Juan de Fuca Ridge. On the central Juan de\nFuca, a low-exit-temperature-type plume was mapped within the caldera of an\naxial seamount.\nShort-term current observations at the southern Juan de Fuca site in 1984\nshowed predominantly northward flow for about 20 days. However, there was an\nindication of some westward flow during the first 5 days, which could have\ncarried the observed plumes to the west. A year-long mooring on the west rim\nof the ridge showed 2 months of northward flow, followed by 8 months of west-\nward flow, and then a return to northward flow for 3 months. Low-frequency\nspeeds were typically 1-2 cm S-1. Tidal oscillations of 4-10 cm s 1 are also\nevident in the data.\nVent particulates from the southern Juan de Fuca and Endeavour Ridge\nsites were studied for their chemical and mineralogical composition by X-ray\n89","diffraction and X-ray microanalysis procedures. Samples from the southern\nJuan de Fuca Ridge consisted mainly of sphalerite, pyrite pyrrohitite, barite,\nelemental sulfur, and two unidentified Fe- and Ca- silicate phases that have\nnot been observed in other hydrothermal systems. These phases are the result\nof mixing intermediate-temperature (200°-270°C) hydrothermal fluids enriched\nin Fe, Si, Zn, Ca, and S with seawater. The major phases emanating from the\nEndeavour Ridge vents included chalchopyrite, anhydrite, pyrite, sphalerite,\npyrrohitite, marcasite, barite, and elemental sulfur. These phases are charac-\nteristic of reactions involving the mixing of high-temperature (290°C) hydro-\nthermal fluids with ambient seawater.\nMicrobial geochemistry studies focused on the role of bacteria in the\nprecipitation and transportation of metals such as Mn and Fe within the plumes.\nTransmission electron microscopy with Xoray micro-elemental analysis was used\nto identify, count, and analyze individual microparticles. Other microbiolog=\nical parameters under study include bacterial number (direct epifluorescent\nmicroscopy) and two independent and complementary measures of biomass (ATP and\nlippopolysaccharide). Additionally, radiotracer experiments were performed at\nsea in order to examine rates of Mn#54 and Fe+59 precipitation under biologi-\ncally controlled conditions.\nEarly results indicate that the metal encrusted capsules of certain bac-\nteria are significant contributors to the plume particulate Mn loads. These\nencapsulated bacteria are very abundant (10-25% of total bacterial numbers)\nand represent the only microparticles, so far, that contain detectable Mn.\nThough Fe deposits are always associated with the capsules, the capsuled bac-\nteria's relative contribution to total plume particulate Fe is variable.\nSampling and shipboard analytical capabilities were further enhanced\nthrough the acquisition of a sea-going Zeeman modulated atomic absorption\nspectrophotometer and several high-resolution CTD systems. A four-chamber,\nremotely activated plume sampler was designed to accompany the horizontally\ntowable CTD system (SLEUTH) which included integrating nephelometers and high-\nresolution transmissometers. These tow-systems provide continuous and real-\ntime sensing and sampling of hydrothermal plumes and allow scientists to\nadjust operational strategies to use ship time most efficiently.\nHigh-resolution deeptow side-scan sonar images were obtained at Axial\nSeamount on the Juan de Fuca Ridge. Ground-truth data were obtained by numer-\nous camera tows and provide the first physiographic map sufficiently detailed\nfor submersible navigation.\nThe Atlantis II/Alvin cruise was specifically designed to survey the\nsurficial extent of the massive sulfide deposits associated with an extinct\nvent site on the Galapagos spreading center as well as to conduct state-of-the\nart magnetics and electrical experiments to define the subsurface extent of\nthe sulfide enrichment. This experiment marked the conclusion of a series of\nNOAA-sponsored diving programs at this site and provided information on the\nduration and volume of vent activity during the entire life cycle of vent\nsystems.\nA VAX 11/750 computer system was brought on line for the primary purpose\nof processing digital SEABEAM bathymetry to produce detailed maps within areas\nof VENTS interest. All previously existing NOAA software to accomplish bathy-\n90","metric data processing was reconfigured to operate on the PMEL system. The\nunique capability for largenscale plotting, in color, of bathymetric maps\nbecame operational approximately 6 months ahead of schedule, and initial map\nproducts were used in FY-1985 VENTS field expeditions.\nFISHERIES-OCEANOGRAPHY RESEARCH\nThe Fishery-Oceanography Experiment (FOX) was funded jointly by PMEL and\nthe Northwest and Alaska Fishery Center (NWAFC) to study the effects of the\nbiotic and abiotic environment on early life stages of pollock in Shelikof\nStrait, Alaska. Field operations for FOX were conducted between August 1984\nand August 1985. They provided initial research for FOCI, which will examine\ninterannual variations in the environment and relate them to fluctuations in\nrecruitment of commercially valuable fish and shellfish stocks. The paradigm\nthat guides this research is that year class strength is primarily determined\nby interactions with predators and prey during early life stages and that vari-\nability in these interactions is a function of fluctuations in the abiotic\nocean climate, which in turn are driven by atmospheric variability.\nFor the stock of pollock in Shelikof Strait, our primary hypothesis is\nthat larvae and juveniles remaining near the coast of the Alaska Peninsula are\nmore likely to survive than those that are transported off the shelf. Ex-\nchange of mass with adjacent slope waters of the Alaskan Stream affects water\nproperties and the composition of plankton communities. These factors can\nalso affect survival at early life stages. Thus, the key process in the\nphysical environment is transport, and the factors that influence its varia-\ntion must be understood.\nThe two major activities of the 1985 fishery-oceanography program were to\nconduct field operations and to synthesize existing data and knowledge regard-\ning the abiotic environment of the Gulf of Alaska. On six oceanographic\ncruises, operations included deployment and recovery of ten current and bottom\npressure moorings; collection of 563 water samples for nutrient analyses, 344\nsamples for estimation of chlorophyll concentration, 449 zooplankton samples,\nand 144 micro-zooplankton samples; acquisition of CTD data at 324 stations;\nand 40 atmospheric radiosonde observations. Nine flights were made with the\nNOAA P-3 research aircraft, to study the unique meteorological conditions in\nPMEL\nShelikof Strait and along the coast of Alaska. Ancillary meteorological data\nwere collected from the ship's weather logs and three land-based platforms\nsouthwest of the strait.\nThe 1985 pollock egg survey in April indicated that abundance was similar\nto that in previous years (1980-84). Spawning occurred at a similar time and\nin about the same location in lower Shelikof Strait. Results of the survey of\nlarvae in early May, however, were markedly different from those for previous\nyears. Few larvae were found, even after the search pattern was expanded to\ncover all areas where larvae might conceivably have drifted, an area four\ntimes larger than originally planned. Four possible causes for the unexpected\nabsence of larvae are under investigation: (1) unusually strong off-shelf\ntransport, (2) mass starvation due to low food abundance, (3) excessive preda-\ntion, and (4) poor condition of the eggs. Wind and current meter data will be\nused to address the question of transport. The other causes will be evaluated\nfrom biological samples collected during FOX.\n91","Preliminary examination of weather and CTD data indicated that anomalous\nconditions existed in early 1985. Throughout January and in early February a\nridge of high pressure existed over the Gulf of Alaska, resulting in a west-\nward displacement of the Aleutian Low. As a result, the primary storm track\nwas northward into the Bering Sea rather than into the Gulf of Alaska. In\nlate winter and early spring, a winter storm pattern rather than a typical\nspring pattern was established with anomalously persistent northerly winds in\nthe region. There was an unusually large number of storms that passed through\nthe western Gulf of Alaska. Although the ramifications of this perturbation\nare not yet fully known, CTD data indicate significant differences between\n1985 and 1981 (a year when the number of larvae collected was several orders\nof magnitude larger than in 1985). During 1985, surface waters were about\n1.5°C colder, the mixed-layer depth was approximately 25 m deeper, and bottom\nwaters were 0.3°C warmer and 0.4 g kg 1 more saline than in 1981. It appears\nthat this condition continued through May. The changes in surface tempera-\ntures and mixed-layer depth suggest the action of increased storm activity;\nthe changes in bottom water characteristics may be related to enhanced trans-\nport in the upper layer with compensating flow of slope waters into the\nShelikof sea valley.\nPlans FY 1986\nVENTS PROGRAM\nField work will continue within specific areas along the Gorda Ridge, to\nsurvey what appear to be hydrothermally active vent sites discovered\nduring the FY-1985 field season.\nTime-series sampling of vent-associated waters will continue at several\nknown active hydrothermal sites along the Juan de Fuca Ridge, in order to\nbegin quantification of the long-term variations in vent fluid output.\nThe detailed photogeologic, seismic, and high-resolution side-scan sonar\nmapping of the Axial Volcano vent fields will be completed in anticipa-\ntion of the arrival of Alvin in FY 1987.\nA series of Alvin dives will be requested to follow up the discovery of\nthe active mid-Atlantic vent fields and bring to a successful close the\nVENTS field work on the Mid-Atlantic Ridge so that full concentration of\nprogram resources can be allocated to the Gorda and Juan de Fuca Ridges.\nThe high-resolution data (e.g., bathymetric and side-scan sonar) process-\ning capability at Newport will be augmented with interactive high-\nresolution graphics capability.\nEfforts will begin, to plan and implement the capability for submersible-\nbased long-term monitoring of selected geological, biological, and\noceanographic variables at the seafloor within and close to the active\nvent systems.\n92","FISHERIES-OCEANOGRAPHY RESEARCH\nAnalyze field observations obtained during the 1985 FOX experiment.\nPrepare a coordinated FOCI planning document with NWAFC.\nConduct field operations in the vicinity of Shelikof Strait to study\nslope/sea valley water exchange processes.\nAssess new measurement techniques for field operation in the Bering Sea\n(e.g., bottom-mounted Doppler acoustic current profilers, satellite-\ntracked drifters, and CTD systems).\nPMEL\n93","","Eugene J. Aubert\nGREATLAKES ENVIRONMENTAL\nDirector\nRESEARCHLABORATORY\nAnn Arbor, Michigan\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nESG\nSTORM\nTOGA\nCRP WRP PROFS WMP\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nWPL\nARL\nAL\nSEL\nThe Great Lakes Environmental Research Laboratory (GLERL) conducts inte-\ngrated, interdisciplinary environmental research in support of resource manage-\nment and environmental services in coastal and estuarine waters, with special\nemphasis on the Great Lakes. The GLERL program includes both basic and\napplied studies and combines experimental, theoretical, and empirical ap-\nproaches. Field, analytical, and laboratory investigations are performed to\nimprove understanding and prediction of environmental processes and their\ninterdependencies with the atmosphere, land, and sediments in coastal and\nestuarine areas. GLERL places special emphasis on a systems approach in\nproblem-oriented research to develop environmental service tools. The prod-\nucts of GLERL research are used by government and private organizations to\nfacilitate planning and decision making in water resources management.\nGLERL\nalso provides end-user assistance to resource managers and others who wish to\napply the information, tools, and services it develops.\nGLERL\nResearch is carried out by five groups: Synthetic Organics and Particle\nDynamics, Ecosystem and Nutrient Dynamics, Lake Hydrology, Physical Limnology\nand Meteorology, and Environmental Systems Studies. Staff specialties include\naquatic chemistry, aquatic biology and toxicology, applied mathematics, meteor-\nology, geology, hydrology, physical oceanography, ecology, computer systems\napplications, instrument design and development, and experimental design and\nanalysis.\nGLERL's multidisciplinary program supports the Ocean and Great Lakes Pre-\ndiction Research Program of NOAA. Decision makers at all levels of government\nrequire access to predictions that improve impact assessment, resource manage-\nment, and safety and economy of operations in the coastal marine environment.\nWith most of the U.S. population residing near the coasts, the ability of the\nadjacent bodies of water to accomodate wastes, and the ability of people to us\nthose water bodies and the surrounding shorelines safely and effectively for\nhousing, transportation, and recreation, must be given increased attention.\n95","The Great Lakes are the largest reservoir of fresh surface water in the United\nStates, but are also sinks for domestic and industrial wastes. Major cities,\nincluding Buffalo, Cleveland, Chicago, Detroit, Milwaukee, Rochester, and\nToledo are located along the shoreline, and more than 30 million people in the\nUnited States take their drinking water from the lakes.\nOcean and Great Lakes Prediction Research at GLERL is designed to improve\nour understanding of the Great Lakes and to provide precise scientific informa-\ntion about the processes that occur within them. GLERL's program addresses\n(1) the need for new and improved simulation and prediction models of eco-\nsystem structure and function, and of the effects of stresses and proposed\nremedial options, and (2) the need to assess other options while taking system\nmetrics into account.\nBiogeochemical studies of the cycling and dynamics of nutrients and toxic\ncontaminants provide precise, sophisticated information relevant to the manage-\nment of wastes, water quality, and fisheries, and form a basis for models that\nsimulate and predict the transport and fate of these contaminants as a func-\ntion of human input to the lakes. Such models are needed to support decisions\nrelated to waste management and regulation, dredging, shoreline use, and\nsiting of facilities. More precise scientific information on lake water\nlevels, connecting channel flows, and ice distribution is critical to those\ninvolved with erosion control, shoreline development, transportation, recrea-\ntion, and power generation. Studies of the lakes' physics lead to better\nunderstanding and prediction of the circulation, the thermal structure, and\nthe transport and dispersion of chemical and biological constituents of the\necosystem; numerical forecast tools result in products applicable to water\nquantity management, pollution transport, and dispersion. Research on physi-\ncal phenomena such as surface waves, seiches, and surges provides a better\nunderstanding of these phenomena and results in improved numerical prediction\nmethods that are applicable to shipping activities, recreation, shoreline\nflooding, and erosion.\nGLERL's programs focus on two elements of the Ocean and Great Lakes Pre-\ndiction Research Program: Marine Ecosystems Assessment, and Marine Hazards and\nLake Hydrology. To ensure that its research products reach the usercommunity\nin a timely manner and are responsive to user-community needs, GLERL maintains\nan Information Services Group. In FY 1985, GLERL research products included\n69 scientific articles, reports, and books, 85 talks presented at scientific\nand public meetings by GLERL staff, and responses to approximately 1,100\nrequests for information, providing more than 1,350 items to service those\nrequests.\nMARINE ECOSYSTEMS ASSESSMENT\nThe Marine Ecosystems Assessment research program at GLERL is designed to\n(1) improve our understanding of, and predictions related to, natural marine\necosystems, physical phenomena and the impact of human-induced stresses on the\necosystem, and (2) help provide a sound scientific basis for management deci-\nsions pertinent to marine resources, marine pollution, and environmentally\nsensitive marine activities. GLERL projects in support of these program ele-\nments include investigations into the short- and long-term effects of human,\n96","agricultural, and industrial wastes on aquatic life and water quality, partic-\nularly in the nearshore zone (the area of maximum use and conflict) the struc-\nture and function of aquatic ecosystems and the effects of human activities on\nthose ecosystems; measurement, analyses, and prediction of physical phenomena\nsuch as currents, river flows, and airowaternsediment interactions; and sedi-\nmentary fluxes and processes, especially sediment-contaminant interactions.\nAccomplishments FY 1985\nSediment traps are an integral part of GLERL's field research, as they\nprovide data on bulk sediment mass flux, as well as samples for analysis of\nindividual component mass fluxes. Sediment traps of different size and design\nfrom GLERL and Canada's National Water Research Institute (NWRI) were deployed\nin tandem at multiple depths on a mooring in Lake Michigan to determine and\ncompare their relative collection efficiencies.\nWinter resuspension of bottom sediments provides recoupling of previously\nremoved contaminant-bearing particles with lake water, and can buffer the\nGreat Lakes system against significant short-term response to reductions in\nnew contaminant loading. Sediment traps were recently retrieved from winter\nmoorings in Lakes Michigan, Superior, and Huron. Traps from multiple depths\nat two sites in Lake Michigan revealed a year-to-year variability in the\nwinter downward mass flux of suspended material. The 1984-85 winter mass flux\nranged from 1.2 to 2.5 times the winter mass flux during 1983-84. All trap\nsamples are being analyzed to determine the downward fluxes of carbon, nutri-\nents, radionuclides, total mass, and organics.\nBottom currents and topographic controls focus sediment deposition in the\nGreat Lakes, resulting in areas characterized by high sedimentation rates.\nMeasurements in cores from such high sedimentation (Hi Sed) areas provide a\nbasis for testing comprehensive timendependent diagenetic models of contamine\nant deposition and history. 137 Cs and 210 Pb profile analyses and dating were\ncompleted for more than 20 cores from Hi Sed areas in the Great Lakes. The\nsignal associated with the large decrease in atmospheric lead flux since 1973,\nreflecting the introduction of \"noelead\" gasoline, shows clearly in the prom\nfile analyses. In collaboration with a University of Wisconsin-Milwaukee sci-\nGLERL\nentist, a comparison was made of sediment deposition focusing in Lake Michigan\nin 1982 and 1972, as shown by the 137 Cs record. Results show that the major-\nity of lake suspended load is rapidly transported and focused to the \"final\"\ndepositional basins within the lake, and within the last decade there have\nbeen small changes in the locations of the Hi Sed depositional basins.\nIn relation to the radionuclide measurements, a regional fallout source\nfunction for long#lived radionuclides (a contaminant surrogate) was con-\nstructed and documented.\nA coupled Lakes Model, which predicts the long-term response of the lakes\nto time-dependent contaminant loads, was developed. A sensitivity analysis of\nthe Lakes Model to sediment resuspension, sediment mixed-layer thickness, and\ncontaminant partitioning coefficient (between solid and dissolved phases) was\ncompleted and documented. Partitioning between dissolved and particulate\n97","(solid) phases was found to have the most significant effect on the half life\nof organic contaminants in the system.\nThe form in which organic contaminants such as polycyclic aromatic hydro-\ncarbons (PAH) are present in the ecosystem affects the availability of the\ncontaminants to the biota. Complementary field and laboratory experiments\nshowed that for particulate matter indigenous to the Great Lakes, there is a\nseasonal variation in sorptive capacity for radiolabeled organic compounds.\nInitial results from kinetic studies indicate that the adsorption process is\nmore rapid than the desorption process. The bioavailability of PAH added in\nthe dissolved form to water decreased when natural dissolved organic material\n(DOM) was also present in the water. A large fraction of the PAH operation\nally defined as \"dissolved\" was actually weakly bound to natural DOM and was\nnot available, for example, to the common benthic amphipod Pontoporeia hoyi.\nAdditional experiments revealed that the partitioning of organic contaminants\nto DOM is related to differences in the characteristics of the DOM, including\nmolecular weight but not compound solubility.\nIn related studies the bioavailability to P. hoyi of PAH in sediments\nexhibited considerable variability, the following parameters being most signif-\nicant: sediment composition, amount of material ingested, and characteristics\nof the organic compound. On the other hand, the bioavailability of PAH to\nMysis relicta (another small shrimp-like freshwater invertebrate) through con-\ntaminated food sources was found to be significant, indicating that food is\nthe single most important pathway for contaminants entering that organism.\nHowever, contaminant accumulation in the organism was variable and may depend\nupon the nature of the food source.\nThe availability of 20+ years of limnologic data from Lake Washington\nprovided a basis for developing and testing a series of general lake ecosystem\nmodels. Results of a heat-diffusion model for Lake Washington revealed that\nthe time required for vertical transport of near-surface phytoplankton by tur-\nbulent diffusion is highly dependent on nocturnal convection events and heat\ninput from the Sun. This affects diurnal phosphorus utilization and therefore\nthe phosphorus budget. The ecosystem models developed for Lake Washington are\nnow being applied to Lake Michigan, using data obtained from the comprehensive\nLake Michigan Ecosystem Experiment.\nData from the Lake Michigan Ecosystem Experiment are also being used for\nstudies of community and species-specific primary production and zooplankton\ngrazing rates. Analysis of a 10-year ecological data set from southern Lake\nMichigan revealed a gradual improvement in water quality over the last decade;\ntwo years showed particularly clear water and low chlorophyll concentration.\nThese are thought to be caused, respectively, by heavy ice cover and ecolog-\nical shifts associated with a decline in alewife abundance.\nStudies of bacterial dynamics are necessary to understand and quantify\nthe transfer of energy and nutrients through the food webs of the Great Lakes\necosystem. Completed analyses of the 1983-84 field data from the Lake\nMichigan Ecosystem Experiment indicate that bacterial growth rates range from\n0.05 to 0.24 h-' and appear to be balanced by grazing losses. Experiments in\nLake Superior demonstrated the importance of microorganisms in ecosystem\nenergy transfer. Cyanobacteria less than 1 um in size were responsible for\n98","approximately 24% of the total primary production and are consumed by small\n(5-20 um) heterotrophic protozoans.\nAn understanding of the mechanisms of zooplankton feeding is necessary to\npredict the effect of zooplankton on food web dynamics, ecological succession,\nand particle transport in the Great Lakes. The process of zooplankton feeding\nand other zooplankton/algal interactions occupies a central role in models of\neutrophication and toxic organic cycling. Progress in developing mechanistic\nmodels has been hindered by the inability to observe the feeding process di-\nrectly because of the small size of both the zooplankton and algae and the\nhigh frequency (50 Hz) of zooplankton appendage movement. Last year, a high-\nspeed microcinematography facility at the Skidaway Institute of Oceanography\nwas used by a GLERL scientist to make the first direct observations of these\nprocesses for a freshwater copepod. During FY 1985, a microcinematography\nlaboratory was established in a prefabricated temperaturemcontrolled environ-\nmental room at GLERL. A high-speed microcinematographic study showed that the\nwater flow field created by the copepod Diaptomus sicilis while feeding, and\nDiaptomus general feeding behavior, differ from those of marine copepods.\nDiaptomus behavior is apparently a specialization for capture of small part-\nicles, which are more abundant in freshwater than in marine waters. The\neffects of feeding history on zooplankton food selection adaptation were also\nstudied. Results showed that Diaptomus exposed to small-diameter algae for 4\ndays had a much greater selectivity (preference) for small cells in a mixture\nof small and large cells than did animals exposed to large cells for 4 days.\nLate summer \"whitings\" occurring on a lake-scale and produced by auto-\ngenic precipitation of calcium carbonate have been reported for Lake Michigan\nsince at least the mid-1960s. A GLERL study of calcium carbonate in Lake\nMichigan seston revealed that calcite constitutes 20-56% of the particle\nvolume during such whitings. Potential ecological effects, which are a func-\ntion of calcite particle size, include decreased light intensity, increased\nsinking rate of fecal pellets, and decreased zooplankton feeding rates. The\nprojected two- to three-fold increase in atmospheric CO 2 over the next century\nmay drastically decrease or eliminate this seasonal event, making it important\nfor study now.\nPhosphorus uptake by microorganisms was investigated to determine the\nmajor pathways of organic and inorganic phosphorus flux through the lower food\nGLERL\nchain. Kinetic studies on nutrient uptake in Lake Michigan showed that bacte-\nria utilize organic phosphorus whereas phytoplankton utilize inorganic phos-\nphorus. These findings provide an improved basis for modeling aquatic phos-\nphorus dynamics.\nModel simulations of the effects of silica limitation on phytoplankton\nspecies succession were performed to determine if limitation of this nutrient\ncauses the observed shift from diatoms to blue-green and green algae in Lake\nMichigan. Analysis of nutrient-uptake kinetics showed that silica limitation\naffects the ability of diatoms to utilize phosphorus, and thus triggers the\nshift to blue-green algae during summer.\nModeling of phosphorus cycling in lakes has been impeded because ortho-\nphosphate cannot be measured accurately. A new kinetic procedure to quantify\nlow-level orthophosphate concentrations in Lake Michigan was developed. The\nmethod is a bioassay procedure that uses natural microbial populations.\n99","The final set of microcosms for determining phosphorus release rates in\nLake Michigan sediments was completed. These data will complement sediment\ntrap data in providing information needed to develop phosphorus transport\nmodels for Lake Michigan.\nA method to determine ammonium excretion by zooplankton in suspensions of\ntheir food, using heat-killed algae, was developed and tested against the flow-\ncell method. The results validated the flow-cell method and provided informa-\ntion about the relationship between nitrogen excretion and feeding history.\nThe potential importance of P. hoyi to remineralizing nitrogen (i.e.,\nconverting organic nitrogen to inorganic ammonium) in recently deposited\ndetritus was estimated by comparing the areal excretion rate of P. hoyi in\nsouthern Lake Michigan to inputs of organic nitrogen in particles collected in\nsediment traps. This calculation suggested that P. hoyi excretion could\naccount for remineralization of up to 40% of the organic nitrogen settling\ninto the hypolimnion and implies the importance of benthic invertebrate\nexcretion.\nDenitrification (conversion of ammonium and nitrate to nitrogen gas)\nrates are needed to quantify the relative importance of invertebrates and\nmicrobes to the remineralizing of nutrients in detrital material in sediments.\nTechniques were developed to measure denitrification rates in lake sediments,\nand a field program was initiated to quantify this process in Lake Michigan\nsediment.\nThe lipid (fat) content of an organism is a measure of its stored energy;\nstudies of the lipid content of lower-food-chain organisms are necessary to\nfollow and understand energy transformations and flow up the food chain.\nMeasurements of the seasonal lipid content of four species of benthic inverte-\nbrates in Lake Michigan showed that animals feeding on suspended material or\nsurface detritus and microbes tend to have higher and more variable lipid con-\ntents than do those feeding on subsurface material. The invertebrates with\nrelatively high lipid content are desirable prey species for small fish.\nThe data base from a study of the long-term trends in benthos populations\nin Lake Michigan was checked, verified, and formatted for publication along\nwith data gathered from previous surveys. Statistical tests indicated that a\nsignificant general increase in the population of several benthic groups OC\ncurred between the mid-1960' and 1980-81. P. hoyi was shown to be the pre-\ndominant benthic macroinvertebrate, constituting about 65% of the benthic\nmacroinvertebrate biomass in southern Lake Michigan.\nStudies of gut contents of P. hoyi indicated that individual P. hoyi\noften have only partially filled guts, implying that feeding by this organism\nmay be periodic rather than continuous. Lipid extracts of P. hoyi and\nStylodrilus heringanus, obtained by microextraction techniques developed at\nGLERL, indicated that most of the lipids in P. hoyi, but not those in S.\nheringanus, are present as the energy=storing triglycerides. The ability of\nP. hoyi to store energy as lipids may help to explain its ability to thrive in\nlowanutrient systems such as the upper Great Lakes and to withstand long\nperiods without food. In a related study, the areal caloric contents of the\nmajor benthic organisms in southern Lake Michigan were calculated. The\n100","results revealed that P. hoyi constitutes about 70% of the total caloric con-\ntent of benthic invertebrates in southern Lake Michigan.\nA GLERL biologist participated in a series of submersible dives during\nthe first exploration of the Great Lakes (Lake Superior) with a research\nsubmersible.\nThe seasonal cycle of thermal stratification in Lake Erie was described,\nincluding thermocline formation and the intermittent progression of thermo-\ncline deepening associated with the passage of storms. The persistence of a\nnear-bottom thermocline was also demonstrated, and the physical basis for\noxygen depletion of bottom waters associated with the water quality issue of\nnutrient overenrichment was examined.\nThe seasonal cycle of Lake Erie circulation was determined. One circula-\ntion cell often dominates the flow in the central basin, in contrast to the\nprediction of two-cell circulation by several numerical models. Seiche cur-\nrents are important over the whole lake, but are strongest in the passages\nbetween the islands that separate the western and central basins.\nAnalysis of the records from current meter moorings in Green Bay showed\nthat during the stratified season, inflow of bottom water from Lake Michigan\nand outflow of near-surface (above the thermocline) water to Lake Michigan\ncontribute substantially to the flushing of Green Bay. A one-layer model\nwould significantly underestimate Green Bay flushing.\nWith the development and testing of user interface subroutines for Great\nLakes physical data bases and the publication of a user's manual, the GLERL\nData Acquisition System is now essentially operational and available for\nstorage and retrieval of research data sets in GLERL's VAX 11/780 computer.\nFurther testing of this system is under way using water level data, current\nmeter data, and climatological weather data.\nAnalyses of the records from a network of 13 current meter moorings de-\nployed in Lake Michigan from July 1982 to July 1983 indicate that rotational\nwaves are confined mainly to the southern basin. Comparisons between data\nanalyses and a one Player numerical prediction model showed some disagreement;\ne.g., a predicted strong oscillatory current across the midlake topographic\nridge was not observed. Analyses of the data for the mean flow field revealed\nGLERL\na very weak circulation during early summer and during the stratified season;\norganized large-scale circulation prevailed only during the fall and winter\nand was cyclonic.\nA vertically integrated model that incorporates Ekman layer sediment\ntransport was developed and is now being applied to Lake Michigan's southern\nbasin and to Lake St. Clair, the latter as part of the Upper Great Lakes\nConnecting Channels Study (UGLCCS) (see below).\nNumerical methods to compute finite difference currents and to estimate\nthe numerical accuracy of trajectory calculations were developed.\nThe new spill model PATHFINDER was formally released for use by the\nNational Weather Service, U.S. Coast Guard (for search and rescue operations),\n101","and the Canadian Weather Service. Spill model verification studies will con-\ntinue by comparing drifter tracks with PATHFINDER predictions.\nA comparison of Eulerian and Lagrangian current data from Lake Michigan\nshowed good agreement in both speed and direction.\nData from 1984 tests of new acoustic current meters (ACMs) deployed in\ntandem with older, reliable vector-averaged current meters (VACMs) close to\nthe bottom of Lake Michigan revealed defects in the ACMs, which were returned\nto the manufacturer for repairs. VACM data collected in the lower 7 to 10 m\nof the water column showed an Ekman veering of the velocity with height and\nsuggested that deployments in the lower 10 to 20 m would be rewarding during\nwinter, when the velocities are larger.\nAnalyses of the data from the 1983 and 1984 driftermslippage experiments\nusing Rhodamine-B dye were completed. Results verify that drifter trajec-\ntories can be explained by the vector sum of a fixed fraction of the wind\nadded to the surface current. These results are applicable to the light wind\nand small-amplitude wave conditions that existed during the experiments.\nGLERL scientists began work as part of UGLCCS, an international\n(U. HCanada) and interagency [U.S: Environmental Protection Agency (EPA),\nNOAA, U.S. Army Corps of Engineers (COE), Department of the Interior Fish and\nWildlife Service (FWS), and Michigan Department of Natural Resources; Canada:\nDepartment of the Environment (DOE)/Environmental Protection Service,\nDOE/NWRI, Inland Waters Directorate, Department of Fisheries and Oceans,\nOntario Ministry of the Environment] multi-year water quality research and\nmonitoring study of the St. Clair River, Lake St. Clair, the Detroit River,\nand the St. Mary's River. GLERL's primary task in this 3-year program is to\nmodel the behavior and fate of nutrients and trace contaminants in the upper\nGreat Lakes connecting channels. The U.S. lead agency is EPA, from which\nGLERL receives partial support by interagency agreement.\nAs part of UGLCCS, GLERL and NWRI (Canada) have developed collaborative\nplans for a shallow water wave experiment in Lake St. Clair. Towers, wave\nstaffs, and other instrumentation are being fabricated and assembled for de-\nployment this fall along a WNW-ESE transect. Data from this experiment will\nbe used to develop and test models of wave growth, propagation, and decay in\nshallow water. Sediment cores were collected by hand (scuba) from 60 sites in\nshallow Lake St. Clair and returned to GLERL for radionuclide processing. A\nsignificant cooperative research effort in support of the GLERL part of UGLCCS\nwas initiated with the University of Michigan and Argonne National Lab ( ANL ),\nusing funds from the NOAA/EPA interagency agreement. A bottomomounted tripod\nbelonging to ANL was equipped with sensitive instruments to measure transpare\nency, current, temperature, and pressure and was deployed in Lake St. Clair.\nThe objective is to develop data sets to describe sediment resuspension, which\ninclude measurements of near-bottom suspended material as well as current\nvelocity (from wave action or other causes).\nA total phosphorus mass balance model for Lake St. Clair is under develop-\nment to support UGLCCS. Tributary loads and rough budget calculations were\nperformed, and studies began, to assess the importance of internal phosphorus\nregeneration in Lake St. Clair. Major mechanisms being evaluated include\nphosphorus release from sediments and phosphorus excretion by mussels.\n102","Microcosm experiments, similar to those done on Lake Michigan sediments, are\nbeing conducted to assess the importance of sediment release.\nThree significant technology transfers of GLERL products in Marine\nEcosystems Assessment took place:\nMethod of Amino Acid Analysis of Natural Waters\nUser: Michigan State University (MSU)\nTrack Autoradiography Procedure\nUsers: University of Southern California and MSU\nMethods of Measuring Primary Production in Lakes and Rivers\nUser: Georgia EPA\nPlans FY 1986\nEquilibrium partition coefficients (the concentration associated with the\nparticle phase divided by the concentration in the dissolved phase) will be\nmeasured seasonally for a selection of radio-labeled synthetic organic com-\npounds in lake water samples. These data are needed for contaminant models.\nSediment trap work will continue at a station 35 km offshore in south-\neastern Lake Michigan. Data from this station were obtained for each of the\npast five years, in order to quantify the natural variations in particle (and\nassociated chemical) fluxes.\nLaboratory studies have indicated that hydrophobic synthetic organic com-\npounds form stable associations with naturally occurring organics, de-\ncreasing their bioavailability. Field/laboratory studies will be conducted to\ndetermine the magnitude of this process.\nThe rate of synthetic organic uptake, depuration, and metabolic transf\nformation will be measured for Hexagenia sp., a major component of the Lake\nSt. Clair benthos. These data will be used in the UGLCCS modeling program.\nGLERL\nWhether Lake St. Clair is a source, trap, or a temporal integrater of\nmaterials being transported from the upper lakes to Lake Erie will be studied\nthrough the collection and analysis (radiotracers, contaminant organics,\nselected metals, and nutrients) of an array of diverwcollected sediment cores.\nData analysis and non-steady-state modeling will continue on sediment\ncores from the Hi Sed regions of all the Great Lakes. Results will be used to\nreconstruct the contaminant history of the Lakes.\nIn-situ measurements of sediment resuspension will be made from remotely\ndeployed bottomemounted instrument arrays in Lake St. Clair. Data will be\nused in calibrating sediment transport models.\nThe long-term monitoring of benthic trends in Lake Michigan will continue.\nEmphasis will be on changes in benthic communities in response to shifts in\npredation pressure.\n103","The abundance and distribution of benthic macroinvertebrates determined\nduring periods of ice cover of Lake Michigan's Grand Traverse Bay will be com-\npared with abundance and distribution immediately prior to and following ice\ncover. Since few studies have examined macroinvertebrate distribution in\nGreat Lakes sediments during the winter months, results will provide greater\nunderstanding of overall changes occurring in benthic macroinvertebrate popula-\ntions throughout the year.\nBenthic production in Lakes Huron, Michigan, and Superior will be\nestimated by measuring oxygen consumption of biota in intact sediment cores.\nResults will be compared with pelagic production estimates as part of an\neffort to document energy cycling through both benthic and pelagic components.\nPhosphorus release rates from sediments in Lake Michigan and Lake St.\nClair will be assessed in relation to other input sources. Also, the role of\nbenthic invertebrates in the release process will be evaluated.\nA study will be initiated to determine changes in the physiological and\nnutritional state of the amphipod P. hoyi in response to seasonal changes in\nfood availability.\nThe use of benthos by fish as a food source will be examined in predator\nexclusion experiments in deepawater areas of Lake Huron or Lake Superior.\nThe importance of metabolic excretion by freshwater mussels as a source\nof nutrients (phosphate and ammonium) will be evaluated in Lake St. Clair\nby\nseasonally measuring excretion rates and estimating abundance of these domin\nnant invertebrates in the lake.\nThe organic carbon and lipid content of sediment trap material will be\ndetermined seasonally to trace energy flow patterns from phytoplankton to the\nbenthos in Lake Michigan.\nThe intermittent feeding strategy of P. hoyi will be examined to evaluate\nthe importance of discontinuous feeding in estimates of the sediment recycling\nrates of P. hoyi. Throughput estimates will be included in future models of\ncontaminant bioaccumulation by P. hoyi.\nSediment trap and core samples from Lake Huron will be analyzed for\nzooplankton remains. Changes in relative abundance and morphology of pelagic\ncladocerans will be used as a basis for reconstruction of food webs.\nPredation rates by stock salmon and trout will be estimated for alewife\nas the primary prey. The resulting empirical estimates of predation rates\nwill be employed in development of a Lake Michigan food web model.\nA combination of high-speed microcinematography and traditional feeding\nexperiments with algae isolated from the Great Lakes will be used to evaluate\nthe importance of algal size and shape in regulating zooplankton feeding.\nData on the contribution of calcite to the total particle-size spectrum\nof Lake Michigan seston will be summarized for 1978-85. Experiments assessing\n104","the impact on the plankton of this autogenically precipitating calcite will\ncontinue.\nA project to assess the rates of primary production in the Upper Great\nLakes will be initiated. Previous rate measurements have been limited to\nshort-term 14C experiments. This project will compare several different\nmethods for measuring the primary production.\nMeasurements of the effects of diel stratification on primary production\nwithin the epilimnion of Lake Michigan will be analyzed.\nThe relative influences of nutrient regulation and food web control on\nwater clarity will be explored by use of a suite of models designed to simu-\nlate long-term ecosystem behavior of Lake Michigan.\nField measurements of the vertical and horizontal, short (diel) and long,\n(seasonal) temporal distributions of bacteria production will be analyzed.\nEstimates of grazing loss rates of the bacterial population and preliminary\ndata on pathways of autotrophically forced carbon will also be summarized and\nanalyzed.\nEstimates of grazing impact by the zooplankton assemblages on the phyto-\nplankton community, determined during the 1983 and 1984 field seasons of the\nLake Michigan Ecosystem Experiment, will be summarized.\nPopulation dynamics (growth, grazing loss, and sinking) of key phyto-\nplankton species of the epilimnetic assemblage, determined during the Lake\nMichigan Ecosystem Experiment in 1983-84, will be analyzed.\nA comparative study of bacteria production and grazing losses is tenta-\ntively planned for the 1986 field season in Lakes Michigan, Superior, and\nHuron.\nhypothesis that bacteria in Lake Michigan are often grazer controlled,\nA\nrather than substrate limited, will be tested by examining kinetic results\nfrom substrate (amino acids) addition experiments.\nThe ammonium excretion rates of two species of estuarine copepods will be\nGLERL\nmeasured. Influences of food type (detritus vs. algae) and season (winter vs.\nsummer) on excretion rates will be examined.\nExperiments on the kinetics of phosphate and silicon uptake by phyto-\nplankton will be evaluated to determine how silicon limitation affects\nphosphate uptake by diatoms.\nExperiments on speciesmspecific growth rates, phytoplankton biomass, and\nthe kinetics of nutrient uptake will be analyzed to test the hypothesis that\nmicroscale nutrient plumes from zooplankton provide a significant phosphorus\nsource for algae. Preliminary results, based on experimental measurements and\nstimulated phosphorus uptake, suggest that plumes provide a significant\nnutrient source.\nExperiments on the kinetics of phosphorus uptake by Lake Michigan micro-\norganisms will be assessed to determine the primary forms of phosphorus prefer-\n105","red by phytoplankton and bacteria and how these two types of organisms compete\nin natural environments. Preliminary results indicate that both microbial\ngroups can coexist because they use different phosphorus sources.\nThe potentials for using immunochemical techniques to determine how micro-\nbial populations are affected by organic contaminants will be explored.\nA threerdimensional numerical circulation model developed at the Geo-\nphysical Fluid Dynamics Laboratory will be tested for applicability to the\nGreat Lakes.\nNumerical simulations of the development of vertical thermal structure in\nLakes Erie and Michigan will be carried out and compared with observations\nfrom thermistor chains.\nRotary spectra and cross spectra of current meter vector time series from\nLake Michigan will be compared with conceptual models of rotational waves in\nclosed basins.\nModels for predicting current patterns and sediment transport in Lake St.\nClair will be coupled and applied to UGLCCS data, and an experiment to measure\nshallow water effects on the growth and dissipation of the wave spectrum in\nrelation to sediment resuspension will be carried out in Lake St. Clair in\ncollaboration with NWRI (Canada).\nThe PATHFINDER spill model will be tested against GLERL's extensive\ncollection of drifter buoy tracks.\nSynoptic observations of currents in Lake St. Clair will be analyzed to\ndetermine the spatial variability of the circulation.\nMeasurements of bottom boundary-layer velocity profiles in southern Lake\nMichigan will be completed and examined for evidence of an Ekman layer.\nTheoretical calculations suggest that sedimentation patterns and sediment rem\nsuspension in deep lakes may be strongly controlled by transport in a bottom\nEkman layer.\nModels for Lake St. Clair will be developed, including an ecological\nmodel, a generic contaminant model, contaminant mass-balance and management\nmodels, and an ecosystems management model.\nStochastic optimization models will be developed for Great Lakes policy\nissues.\nMARINE HAZARDS AND LAKE HYDROLOGY RESEARCH\nMarine Hazards and Lake Hydrology research focuses on (1) improving pre-\ndiction of environmental phenomena associated with the National Weather\nService (NWS) marine warning and forecasting services and the U.S. Army Corps\nof Engineers regulation of Great Lakes water flow, and (2) providing better\ntools and methods for short- and long-term assessments of water resources of\nlarge lakes. GLERL research in these areas includes field and analytical in-\n106","vestigations to develop simulation and prediction models of over-water wind\nand wind-waves, water surface oscillations, storm surges, and flooding; lake\nice formation, growth, movement, and break-up; and hydrologic lake levels,\nwater supplies and balance, and flows in the connecting channels. GLERL staff\nwork closely with colleagues at the forecasting and warning service agencies\nto assure that GLERL products meet the needs of the operational forecasters.\nProducts released to the user community continue to be improved by GLERL re-\nsearchers, either by fine tuning or by the addition of new tools and\ncapabilities.\nAccomplishments FY 1985\nA water supply and lake level forecast model for Lake Champlain was\ndeveloped from the GLERL Large Basin Runoff Model, and operational software\nwas transferred to the NWS River Forecast Center (RFC), Hartford, Conn., for\nuse on its minicomputer. Model studies indicate that net groundwater flux to\nthe lake is significant. The package supplied to NWS generates distributed\nparameter deterministic or probabilistic water supply and lake level outlooks\non a near-real-time basis.\nA data acquisition and reduction system was integrated with a numerical\noutlook/forecast system for Lake Superior water supply and was transferred to\nthe U.S. Army Corps of Engineers (COE), Detroit District, for its use. A\nstudy of total basin supplies, comparing results from the GLERL model with\nthose from a water balance approach, suggests that further model improvements\nof equal amounts could be obtained by improving runoff estimates or by improv-\ning evaporation and precipitation estimates. Procedures for rapid determina-\ntion of areal averaged snow water equivalent from gamma radiation snow surveys\nwere developed in cooperation with the NWS North Central RFC and the COE.\nThese procedures were incorporated with the software package; they are used\nfor the winter and spring water supply forecasts, and were included in the\npackage installed for the COE, Detroit District.\nContinuous electromagnetic and acoustic current meter measurements are\nbeing made in the St. Clair and Detroit Rivers to develop a data base in sup-\nport of improved river flow modeling for winter ice conditions. A case study\nGLERL\nof the record ice jam of April 1984 in the St. Clair River was completed and\ndemonstrated that existing river flow models are inadequate for winter ice\nconditions.\nThe water levels in the Great Lakes reached record highs during spring\n1985, causing shoreline flooding and hazardous conditions for riparian owners.\nThis resulted in many information requests to GLERL from the news media and\nothers on the cause of this phenomenon and the outlook. An analysis indicated\nthat the primary cause was high precipitation in December 1984 and much higher\nthan normal precipitation during winter and early spring 1985, combined with a\nsudden thaw in early February. GLERL participated in special briefings organ-\nized by the International Joint Commission for the Great Lakes public, the\nU. S. Congress, and State legislators.\nSpectral reflectance was measured for different types of snow and ice on\nSaginaw Bay during March 1985, using a programmable band radiometer mounted on\n107","a helicopter. These measurements characterize the visible and near-infrared\nreflectance (and thus transmission/absorption) under clear sky conditions.\nThe data will be analyzed and summarized for specific snow and ice types.\nAnalysis of data for Lake Erie ice motion from four satellite-tracked\nbuoys deployed in the ice during winter 1983-84 revealed much greater motion\nthan was expected. The data showed that Lake Erie ice motion is usually small\n(0 to 5 cm sHi), but on occasion ice movements at speeds of 20m46 cm Sth were\nobserved.\nMarine weather forecasters at the NWS Great Lakes Weather Service Fore-\ncast Offices (WSFOs) continued to use the GLERL Interactive Wave Prediction\nModel with favorable comments. At the request of the Cleveland WSFO, an air-\nsea temperature difference parameter was added to the forecast program; the\nusefulness of this additional parameter is being evaluated.\nAn evaluation of the GLERL Numerical Wave Prediction Model showed that it\nwill not be feasible to include shallow water effects by modifying the exist-\ning model, because the wave momentum equations in that model do not provide an\nadequate theoretical framework for that purpose. Collaboration was initiated\nwith a scientist at Woods Hole Oceanographic Institution to apply his shallow\nwater wave model to the GLERL shallow water data from Lake Erie. If prelimine\nary tests are encouraging, this model may be applied to Lake St. Clair.\nThe GLERL Wave Rider Information Processing System (WRIPS) wave buoy,\nwhich sends data via satellite, was successfully deployed during September,\nOctober, and November 1984 in western Lake Erie. It was moored near a\nNational Data Buoy Center (NDBC) NOMAD buoy to determine the comparability of\nwave measurements from the two types of buoys, WRIPS being a small (approxi-\nmately 1 m diameter) sphere and NOMAD having a large (6-8 m) boat-shaped hull.\nThe results from more than 1,000 paired measurements indicated that the NOMAD\nbuoy significantly under-reports waveheights of less than 0.5 m; otherwise,\nreported waveheights compared extremely well (correlation coefficient 0.99,\nrms error 7 cm).\nWith 1981 NDBC data from the Great Lakes, a generalized wave spectrum\nrepresentation was developed as a function of significant waveheight and aver-\nage wave period. The result is free from any empirically derived coefficients\nand exponents, and may be used for coastal and marine engineering\napplications.\nFive significant technology transfers took place:\nPATHFINDER Trajectory (spill) Model\nUsers: NWS-National Meteorology Center and WSFOs in Chicago, Ann\nArbor, Cleveland, and Buffalo\nUSCG and Canadian Weather Service\nLake Champlain Water Supply Model\nUser: NWS-RFC in Hartford\nGLERL Interactive Wave Prediction Model\nUsers: NWS-WSFOs in Clevelana, Ann Arbor, Buffalo, and Chicago\n108","Lake Superior Water Supply Model\nUser: COE (Detroit District)\nProcedure to Estimate Snow Water Equivalent from Gamma Radiation\nMeasurements\nUser: COE (Detroit District)\nPlans FY 1986\nA procedure will be developed to derive lake*wide reflectance values, and\ntechniques will be developed for ice type identification/classification from\nsatellite imagery.\nUnder a pilot program, a catalog of pertinent meteorological parameters\nand associated ice cycle types based on the variation of annual ice cycle\ncharacteristics for a major subbasin of one Great Lake will be developed to\nassess the usefulness of this technique in improving NWS ice forecasts.\nThe GLERL Great Lakes Basin Supply Forecast package will be implemented\nfor the entire Great Lakes system, and integrated with the Hydrologic Response\nModel. It will include improved lake evaporation forecasts and estimates of\nnet groundwater flux to the lakes.\nCapabilities will be developed for the system-wide assessment of the im-\npacts of major new diversions, increased consumptive uses, and climatic\nchanges on Great Lakes levels.\nThe flow variability and characteristics of the St. Clair and Detroit\nRivers will be determined, and an unsteady flow model of the total St. Clair\nRiver will be tested against data collected during FY 1985.\nGLERL will continue to provide support for the Interactive Wave\nPrediction Model.\nWind, wave, and temperature data recorded by NDBC NOMAD buoys in the\nGreat Lakes will be analyzed and used to develop climatological information on\nGLERL\nGreat Lakes waves.\nTheoretical predictions of the shape of the wave spectrum in shallow\nwater will be compared with data from the LEX-81 Coastal Boundary Layer\nExperiment.\nINTERNATIONAL AND INTERAGENCY ACTIVITIES\nGLERL staff participated as members (unless noted otherwise) of the fol-\nlowing International Joint Commission boards, committees, and task forces:\nInternational Great Lakes Technical Information Network Board\nSystems Evaluation Committee\nHydrology Committee\n109","International Great Lakes Levels and Flows Advisory Board (U.S.\nCo-Chairman)\nGreat Lakes Water Quality Board, Surveillance Work Group\nUpper Connecting Channels Task Force\nLake Michigan Task Force\nLake Erie Task Force\nTask Force on In-Place Sediment Contaminants, Workshop on\nMonitoring in Areas of Concern\nGreat Lakes Science Advisory Board\nGreat Lakes Levels Task Force (Chairman)\nGreat Lakes Research Strategy and Toxic Contaminants\nCommittee\nHealth and Aquatic Communities Workgroup (Advisor)\nTask Force on Great Lakes Modeling\nGLERL staff participated as members (unless noted otherwise) of other\ninteragency and international activities:\nUpper Great Lakes Connecting Channel Study (UGLCCS)\nManagement Committee\nActivities Integration Committee\nModeling Task Force (Chairman)\nCoordinating Committee for Great Lakes Hydraulic and Hydrologic Data\nRiverflow Subcommittee\nU.S.-Canada Ice Information Working Group (U.S. Co-Chairman)\nJournal of Great Lakes Research (Associate Editors)\nInternational Association for Hydrologic Research\nSection on Water Resources Systems (U.S. Representative)\nGLERL staff participated in an interagency Great Lakes planning activity\nwith NOAA/NMPPO and Great Lakes representatives of EPA, FWS-Great Lakes\nFisheries Laboratory, and COE to develop an \"Action Plan for Federal Research\nand Monitoring Related to Great Lakes Water Quality and Water Quantity.\"\nActivities involving participation with other NOAA units included the\nNOAA\nMarine Environmental Quality Task Force (OAR Technical Representative),\nthe Synthetic Organics Research Subcommittee (Chairman), the Habitat Modifica-\ntion Research Subcommittee (Member), the Nutrient Overenrichment Research Sub-\ncommittee (Member), and the NOAA Technical Subcommittee, New Bedford Superfund\nAction (Member). .\nGLERL scientists participated on the Executive Board of IAGLR as\nPresident and Secretary. IAGLR is the primary Great Lakes research profes-\nsional society and is involved with coordinating programs and disseminating\nresults.\n110","One GLERL scientist was a member of the National Research Council Confern\nence on Review of the Great Lakes Water Quality Agreement, and another presen-\nted a 2-day short course on Toxic Substances in the Great Lakes in conjunction\nwith Michigan Sea Grant at MSU.\nGLERL\n111","","GEOPHYSICAL FLUID DYNAMICS LABORATORY\nJerry D. Mahlman\nPrinceton, New Jersey\nDirector\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nAOML\nWPL\nARL\nAL\nSEL\nPMEL\nGLERL\nGFDL\nNSSL\nThe Geophysical Fluid Dynamics Laboratory (GFDL) is engaged in comprehen-\nsive long-lead-time research fundamental to NOAA's mission. The goal is to\nexpand the scientific understanding of the physical processes that govern the\nbehavior of the atmosphere and the oceans as complex fluid systems. These\nfluids can then be modeled mathematically and their phenomenology studied by\ncomputer simulation methods. In particular, GFDL research concerns the follow-\ning:\nPredictability of weather, large and small scale.\nStructure, variability, predictability, stability, and sensitivity of\nclimate, global and regional.\nStructure, variability, and dynamics of the ocean over its many\nspace and time scales.\nGFDL\nInteraction of the atmosphere and oceans; how the atmosphere and\noceans influence and are influenced by various trace constituents.\nEarth's atmospheric general circulation within the context of the\nfamily of planetary atmospheric types.\nThe scientific work of the Laboratory encompasses a variety of disci-\nplines: meteorology, oceanography, hydrology, classical physics, fluid dynam-\nics, chemistry, applied mathematics, and numerical analysis. Research is\nfacilitated by the Geophysical Fluid Dynamics Program, which is conducted col-\nlaboratively with Princeton University. Regular Princeton faculty, visiting\nscientists, and graduate students participate in theoretical studies, both\nanalytical and numerical, and in observational experiments, in the laboratory\nand in the field. The program is supported, in part, by NOAA funds. Visiting\n113","scientists may also be involved in GFDL research through institutional or\ninternational agreements, or through temporary Civil Service appointments.\nWEATHER SERVICE\nDuring the past two decades synoptic-scale weather forecasts have\nimproved considerably because of the development of numerical models that\ninclude more of the physical processes of the atmosphere, have high spatial\nresolution, and parameterize turbulent processes more accurately. Successful\nforecasts for periods up to a few days are now possible, and the limits of\natmospheric predictability have been extended to several weeks; however,\nquantitative precipitation forecasts remain elusive. For smaller spatial\nscales, there has been considerable progress in determining the mechanisms\nthat generate severe storms, in explaining how mesoscale phenomena interact\nwith the large-scale flow, and in simulating the genesis, growth, and decay of\nhurricanes.\nThis success in the extension of atmospheric predictability encourages us\nto pose more challenging questions. Can the weather be predicted on time\nscales of months? Are mesoscale weather systems and regional-scale\nprecipitation patterns predictable, and if so, is the accuracy dependent on\nthe prediction of the ambient synoptic flow? Research to develop mathematical\nmodels for improved weather prediction will also contribute to the\nunderstanding of such fundamental meteorological phenomena as fronts,\nhurricanes, severe storms, and tropospheric blocking.\nAccomplishments FY 1985\nAn extended series of 30-day forecasts using numerical models was\ncompleted for evaluating the feasibility of long-range prediction. The score\nstatistics for eight January cases show an encouraging degree of predictive\nskill for the time-averaged flow in the 20-30 day range. To attain usable\nskill levels, however, it has been necessary to subtract the model's known\nclimatic bias from the forecasts. This study marks the first quantitative\ndemonstration of predictive skill by numerical models in the monthly forecast\nrange.\nA new National Meteorological Center (NMC) spectral medium-range\nforecasting model was developed by including the GFDL subgrid-scale physics\npackage. In quasi-operational runs launched during January 1985, the useful\nforecast range was extended from -4.5 days to ~6 days. This represents a\nbreakthrough in forecast accuracy, as compared with the existing operational\nmodel. The new model has become the NMC operational model.\nAn analytical theory of the distribution of eddy fluxes along storm\ntracks was developed. The theory is based on baroclinic instability of\nzonally varying flows, and reproduces many of the features in the\nobservations.\n114","It was shown that the response of a baroclinic atmosphere to a pulsating\nlocalized forcing consists of a baroclinic wavetrain that amplifies with\ndistance downstream of the source, in addition to the more familiar\nequivalentbarotropic Rossby wavetrains. The amplification rate is appreciable\neven at quite low frequencies. This spatial instability has implications for\nthe nature of low-frequency atmospheric variability.\nThe effects of mountainous islands on the behavior of tropical cyclones\nwere investigated. Three regions of high tropical cyclone frequency were\nselected: Caribbean Sea region, Taiwan, and Luzon, Philippines. Results show\nthat the storm's track and speed can be significantly affected by island\nmountains. The intensity change upstream of islands can be caused by the\nadvection of relatively dry air from the land. These and other results\nsuggest that inclusion of detailed topography and accurate treatment of\nboundary layer processes are important for the prediction of tropical\ncyclones.\nA forecast study of the genesis of Hurricane David (1979) is in progress.\nThe analysis shows that latent heat release is a necessary process even at the\nstorm genesis stage. The distribution of computed rainfall intensity compares\nfavorably with the cloud satellite imagery. Also, the movement of the model\nstorm for 72 h is in fairly good agreement with the observed track. These\npreliminary results provide encouragement for further exploration of the\nforecasting skill of the hurricane model.\nA study of the evolution of mesoscale disturbances on a mean baroclinic\nstate demonstrated the importance of localized surface heating in producing\nthe rapid development of short baroclinic waves. These waves have a depth on\nthe order of that of the boundary layer and horizontal scales of a few hundred\nkilometers. In the presence of moisture, release of latent heat will cause\nthe waves to develop explosively into an intense meso-cyclone.\nThe Presidents' Day snowstorm (18-20 February 1979) was successfully\n\"predicted\" using a limited-area model nested in a global spectral model.\nStarting from coarse initial conditions, a mesoscale disturbance developed\nwith the aid of strong surface sensible and latent heating. This disturbance\nrapidly intensified through latent heat release. Varying the initial and\nboundary conditions had only minor effects on the model solutions. However, a\nhigher model resolution was required in order to produce accurate forecasts of\nGFDL\nthe storm's structure, intensity, and position.\nThe stability analysis of a linear representation of a convectively\nunstable cloud region and its stably stratified subcloud layer indicates some\nof the parameters that determine the structure of low-level updrafts\nassociated with convective systems. A simple relationship was found between\nthe vertical convergence field and characteristics of the stable lower layer,\nwhich allows one to predict whether a single (vertical) or dual (upshear\nsloping) updraft will occur in the subcloud layer.\nFour-hour numerical simulations were carried out for a north-south squall\nline observed on 22 May 1976 in west-central Oklahoma. In this calculation a\nline of precipitation extended in a nearly unbroken form across the 32-km\nnorth-south domain of the model. The propagation speed of the line, the\nsurface cooling behind the gust front, and the point values of precipitation\n115","were in reasonable agreement with the observed values. In all simulations a\nsignificant down-gradient vertical momentum flux was found in regions with\nstrong shear in the zonal wind component. This preliminary result suggests\nthat parameterizations of moist convection, in general circulation models,\nshould include the effect of vertical momentum transfer.\nPlans FY 1986\nA variety of approaches to the wave amplification and cyclogenesis prob-\nlem will be tested, using analytical and numerical techniques.\nNumerical models will be under continual development to improve fore-\ncasting of the large scale, the mesoscale, hurricanes, and squall lines, with\nemphasis on improved parameterizations.\nDiagnostic analysis will be employed to improve understanding of these\nshorter range processes.\nCLIMATE\nThe purpose of climate-related research at GFDL is twofold: to describe\nexplain, and simulate climate variability on time scales from seasons to\nmillennia; and to evaluate the climatic impact of human activities such as the\nrelease of CO2 and other gases in the atmosphere. The phenomena that are\nstudied include large-scale wave disturbances, and their role in the general\ncirculation of the atmosphere; the seasonal cycle, which must be defined\nbefore departures from the seasonal cycle (interannual variability) can be\nunderstood; interannual variability associated with phenomena such as the El\nNiño/Southern Oscillation; very-long-term variability associated with the ice\nages; and the meteorologies of various planets, the study of which enhances\nour perspective on terrestrial meteorology and climate. To achieve these\ngoals, both observational and theoretical studies are necessary. Available\nobservations are analyzed to determine the physical processes by which the\ncirculations of the oceans and atmospheres are maintained. Mathematical\nmodels are constructed to study and simulate the ocean, the atmosphere, the\ncoupled ocean-atmosphere-cryosphere system, and various planetary atmospheres.\nAccomplishments FY 1985\nThe geographical distribution of soil moisture change in response to an\nincrease of atmospheric CO 2 2 was investigated by use of an atmospheric general\ncirculation model (GCM) coupled with a simple model of the mixed-layer ocean.\nThe results of this study indicate that, during summer, soil moisture is ex-\npected to be reduced over extensive regions of the North American and Eurasian\ncontinents in middle and high latitudes.\nThe climate of the last glacial maximum was simulated using two versions\nof a coupled atmosphere/mixed-layer ocean model with fixed and predicted cloud\n116","cover. In both versions, the reduced glacial CO2 concentration as inferred\nfrom ice core measurements was incorporated. A comparison of these experi-\nments with a variety of paleoclimatic data indicates reasonably good agreement\nin simulating the ice age cooling over both oceans and continents, suggesting\nthat these models may be used with increased confidence.\nThe atmosphere/mixed-layer ocean model was used to study the individual\ncontributions of expanded continental ice, reduced atmospheric CO2, and vegeta-\ntion-induced changes in land albedo to the maintenance of the cold climate of\nthe last glacial maximum. The expanded continental ice sheets were found to\nmake the largest contribution to the ice age cooling on a global basis, and\nthe reduced CO made an important additional contribution, especially in the\nSouthern Hemisphere.\nLinear simulations of the interannual variability produced by a GCM sug-\ngested that anomalous transient eddy fluxes are of greater importance than\nanomalous heating or orographic forcing in generating the anomalous extra-\ntropical stationary waves in El Niño years. These results reveal that the\ntransient disturbances portray a much more dominant role in atmospheric inter-\nannual variability than had heretofore been speculated.\nSpace-time spectral analysis of a spectral general circulation model\n(GCM) indicated that the tropical 40-day oscillations are qualitatively well\nsimulated, although the simulated amplitude is somewhat smaller than that\nbased on FGGE IIIb data. Further statistical analyses indicate that this trop-\nical phenomenon is linked to circulation features in the wintertime extra-\ntropics, as well as to the summer monsoon over South Asia.\nExperiments using a GCM with a zonally uniform surface indicated that\nwave-wave energy transfer is an important source of energy for transient ultra-\nlong waves in their growing stage, but plays a less important role in their\nmature stage.\nA global coupled ocean-atmosphere model with realistic topography and\nannual mean insolation was time integrated to an equilibrium solution. The\nsimulation of the coupled system by this model was found to be substantially\nsuperior to a previous simulation by a model with relatively lower resolution\nand higher subgrid-scale viscosity.\nGFDL\nThe new experimental 1° latitude version of the SKYHI troposphere-strato-\nsphere-mesosphere GCM achieved some important advances in simulation capabil-\nity in all regions of the atmosphere. These advances have allowed planning\nfor future applications in climate and in atmospheric chemistry. The most\nnotable improvements include stratosphere winter polar cold bias, tropospheric\njet stream location, tropical zonal winds, surface pressure, eddy kinetic\nenergy and planetary wave amplitudes, cyclone dynamics, tropical tropopause\ntemperatures, the mesoscale energy spectrum, and interaction between gravity-\nwave and planetary scales.\nThe first large-scale modeling attempt to evaluate directly the effect of\ngravity waves on planetary scale flows was completed. Using a 3° latitude\nversion of the SKYHI model, the analysis shows that gravity waves moving with\nphase speeds similar to the large-scale flow are strongly absorbed in the\nlower stratosphere. The remaining waves propagate to the upper stratosphere\n117","and lower mesosphere where they are absorbed mainly by turbulent dissipation.\nThis absorption acts to produce strong decelerations of both easterly and\nwesterly flows, in addition to providing a strong damping on the planetary\nwaves Preliminary testing with the 1° latitude SKYHI model shows yet larger\neffects, suggesting that these effects are even stronger in the actual atmos-\nphere.\nA coupled ocean-atmosphere model indicated a new feedback mechanism in\nthe response of the climate system to an increase of greenhouse gases. For\nlarge perturbations from equilibrium, a climate warming produces a partial\ncollapse of the ocean's thermohaline circulation. This allows the ocean to\nsequester more heat than would be possible for a normal circulation, augmen-\nting the delaying effect of the ocean on climate response to a CO induced\nwarming.\nAn equation capable of describing all scales of geostrophic motion and\nthe interactions between such motions in high and low latitudes was obtained.\nThis formulation has proved useful for defining and describing oceanic and\nJovian eddies and currents on planetary, intermediate, and synoptic scales.\nSolitary coherent vortices resembling Jupiter's great Red Spot were simu-\nlated for periods in excess of a century, and some of the factors controlling\ntheir genesis were isolated. These factors include the inhomogeneity of the\ninitial perturbation, the width and criticality of the shear zone, and the\nhistory of the interactions.\nOn the basis of the observed semidiurnal tidal radiances, the presence of\na strong middle-latitude jet at about 75 km in the Venus atmosphere was de-\nduced from theoretical considerations for the first time. This is very signif-\nicant because it is impossible to observe the mean wind structure of Venus\ndirectly with existing instruments.\nGlobal computations of the observed divergence of water vapor show that\nthe strongest source of water vapor is located over the eastern Arabian Sea\nduring the summer months. The evaporation over this region (with maximum\nvalues of up to 100 cm/month) must be a very important source of water vapor\nfor the Indian monsoon, probably exceeding the supply of Southern Hemisphere\nwater vapor carried toward India by the Somali jet system.\nPlans FY 1986\nDetailed analyses of important budgets for an Earth warmed by a green-\nhouse gas and an Earth during the ice age will be under way.\nModel development will continue on a number of climatically significant\ntopics. These include a coupled atmosphere-ocean system, the stratosphere,\nhigher computational resolution, radiative transfer, subscale closure, and\nsources of remaining climatic biases in the various models.\nMany diagnostic and theoretical analyses will be undertaken on transient\nand standing flows and on their interaction. Diagnostic analysis will con-\ntinue with emphasis on global dynamical climatology, as well as an increased\n118","emphasis on regional problems such as those of the Southern Hemisphere, polar\nregions, southeast Asia, and the central Pacific.\nThe GFDL work on dynamical aspects of ocean climate will continue.\nATMOSPHERIC QUALITY\nThe main goal of atmospheric quality research at GFDL is to understand\nthe formation, transport, and chemistry of atmospheric trace constituents on\nregional and global scales. Such understanding requires judicious combina-\ntions of theoretical models and specialized observations. The understanding\ngained will be applied toward evaluating the sensitivity of the atmospheric\nchemical system to human activities.\nAccomplishments FY 1985\nA series of model experiments that explore the global impact of the North\nAmerican combustion sources of reactive nitrogen (NOX) was completed. This\nproblem is of special concern because of its possible impact on the chemistry\nof\nozone in the \"unpolluted\" troposphere, in addition to its well recognized\nrole in the \"acid rain\" problem. Preliminary conclusions from this work\nsuggest that about 50% of the combustion source returns directly to the source\nregion as dry deposition, 25% returns through rainout, and about 25% is ex-\nported to more remote regions.\nFor the first time, a two-dimensional (2-D) tracer transport model succes-\nsfully reproduced zonally averaged results from its \"parent\" 3-D transport\nmodel. The transport coefficients and meridional circulations were derived\nfrom the 3HD model in a completely self-consistent manner. These data sets\nwere then used to assemble a 2-D model capable of running completely indepen-\ndent of the 3-D model. This process has provided fundamental new insights\ninto the transport mechanisms acting in the 3-D model. A number of 2-D model\ncomparisons with the 3-D model yield generally excellent results. This method-\nology is already being widely used throughout the chemical modeling community.\nGFDL\nThe vertical mixing of passive tracers initially confined to the boundary\nlayer was examined. Calculations with a moist convection model were carried\nout for a fully insoluble tracer and an infinitely soluble tracer. Present\nresults indicate that significant amounts of the insoluble tracer can be\nadvected into the upper troposphere by convection, whereas rainout prevents\nall but a small fraction of the soluble tracer from reaching the upper atmos-\nphere. Also, there is an indication that much more of the insoluble tracer is\nadvected above the 6 km level by line convection than by isolated cells.\n119","Plans FY 1986\nWork will continue on the regional/global transport, chemistry, and re-\nmoval of chemically and climatically important trace gases. A self-determined\nozone chemistry will be inserted into the SKYHI GCM.\nMoist chemical removal parameterization processes will be developed for\nuse in convective and large-scale models.\nMARINE QUALITY\nResearch at GFDL related to the quality of the marine environment has as\nits objectives the simulation of oceanic conditions in coastal zones and in\nestuaries, the modeling of the dispersion of geochemical tracers (e.g., tri-\ntium, radon) in the world oceans, and the modeling of the oceanic carbon cycle\nand trace metal geochemistry. For regional coastal studies, two- and three-\ndimensional models of estuaries such as the Hudson-Raritan and Delaware Estu-\naries are being developed. The response of coastal zones to transient atmos-\npheric storms and the nature of upwelling processes (which are of great impor-\ntance to fisheries) are being studied by means of a variety of models. Basin\nand global ocean circulation models are being developed for the study of the\ncarbon cycle and trace metal cycling.\nAccomplishments FY 1985\nThe important role of persistent salinity anomalies in generating asym-\nmetric interhemispheric ocean flows in the presence of symmetric forcing about\nthe Equator was demonstrated in a sector ocean general circulation model.\nThis result is part of an ongoing study to understand what factors control the\ndeep ocean circulation, how this might be affected by climate changes, and how\nocean circulation changes will affect the carbon cycle.\nA seasonally driven model of the Atlantic Ocean developed for tracer\nstudies showed a dramatic change in oceanic heat transport associated with the\ncycle of the North Equatorial Countercurrent. The model is being used to\nstudy the role of seasonality in thermocline and deep ocean ventilation.\nStudies of oceanic nutrient measurements demonstrated the importance of\ndiapyenal mixing processes in the Equatorial region and beneath the\nMediterranean Sea salt tongue. The observations are being analyzed in order\nto develop a data base for carbon cycle models.\nAn observational and numerical modeling study of the Delaware Estuary\nstarted, in collaboration with National Ocean Service scientists. It was\nfound that most but not all of the sea level variability due to winds can be\ncalculated, even though the alongshore extent of the model shelf is limited.\n120","Plans FY 1986\nAn effort will be initiated to incorporate biological effects in a\ncoupled carbon-cycle/ocean GCM.\nA wide range of analyses of ocean tracer data relative to ocean dynamical\nstructure will continue.\nOCEAN SERVICES\nVarious models that can be used for the prediction of oceanic conditions\nare being developed at GFDL. The simpler models are capable of predicting\nrelatively few parameters. For example, one-dimensional models of the turbu-\nlent surface layer of the ocean predict the sea surface temperature and heat\ncontent of the upper ocean. More complex three-dimensional models are being\ndeveloped to study phenomena such as the time-dependent development of Gulf\nStream meanders and rings, the generation of the Somali Current after onset of\nthe southwest monsoons, the response of coastal zones to atmospheric storms,\nand the development of sea surface temperature anomalies such as those ob-\nserved in the tropical Pacific Ocean during El Niño-Southern Oscillation pheno-\nmena.\nAccomplishments FY 1985\nA simple coupled ocean-atmosphere model indicates that El Niño conditions\n-shigh sea surface temperatures over the entire tropical Pacific Ocean, and\nweak trade winds--cannot persist indefinitely because the coupled system is\nunstable in this state. Perturbations will amplify and will restore horizon-\ntal sea surface temperature gradients, and intense tradewinds.\nA model of an idealized subtropical gyre circulation with steady external\nboundary conditions exhibits large scale, internally generated pulsations in\nthe gyre structure on the time scale of years. These pulsations are accompan-\nied by complex changes in the intensity and spatial distribution of convection\nand ventilation. Unexplained multimyear time dependence observed in ocean and\nGFDL\nclimate systems may be related to this model-simulated phenomenon.\nPlans FY 1986\nDetailed analysis of the behavior of ocean models will be under way with\nspecial emphasis on the new higher resolution models.\nWork will continue on ocean model development with emphasis on ice dynam-\nics, turbulent closure, and isopycnal coordinates.\nDetailed comparisons of estuary model behavior against observations will\nbe carried out.\n121","","Edwin Kessler\nNATIONAL SEVERE STORMS LABORATORY\nDirector\nNorman, Oklahoma\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nAL\nSEL\nNSSL\nWPL\nARL\nAOML\nPMEL\nGLERL\nGFDL\nThe National Severe Storms Laboratory (NSSL) develops improved means for\nweather observing and forecasting through studies of storm processes, numeri-\ncal and conceptual modeling of storm phenomena, and applications of new tech-\nnologies in remote sensing. New technological developments, new scientific\ndiscoveries, and new requirements are reflected in changing approaches to\ngoals of accurate precipitation forecasts and storm warnings well in advance\nof events. Recent studies have drawn heavily on observations by Doppler radar\nand lightning-mapping systems, and we have developed more effective methods\nfor utilizing Doppler radar and lightning data for forecasts and warnings of\nsevere storms.\nThe last several years will be seen as a watershed for research and devel-\nopment activities at NSSL. The work at NSSL, probably the most substantial\nprecursor of the major national initiative NEXRAD continues to support that\nprogram in critical ways. Other work at NSSL is providing a base in under-\nstanding to support deployment and use of national networks for lightning sens-\ning. During two decades NSSL has examined individual storm cases to garner\nNSSL\nsignificant bits of knowledge about physical processes in the storms. These\ncase studies continue, but we are now seeing significant maturation of both\nour knowledge and our tools. We now understand the processes by which initial\nspinup occurs in tornadic storms, we know how fields of wind and water sub-\nstance are interrelated, and we have good methods for interpreting three-\ndimensional detail observed by modern sensors and for communicating essential\ninformation rapidly to forecasters. Means are within our grasp to extract\nsubstantial new meteorological information from radar data through utilization\nof diversely polarized transmissions and advanced capabilities in data process-\ning. The Laboratory now has access to a state-of-the-art computational capa-\nbility, and fine numerical models for both analysis and forecasting. There is\na plan of action to bring edge-of-the-art capabilities for data synthesis to\nthe Laboratory during the coming year, and our tools are starting to address\nthe important problem represented by forecasting precipitation in the 0-12\n123","hour range. For example, during 1985, an important mesoscale numerical model\nwas brought to operational status at NSSL and applied to a classical cyclo-\ngenetic situation with gratifying results.\nThe Laboratory has a 50-station capability for digital recording of sur-\nface meteorological parameters, and maintains instrumentation on the tallest\ntower in the United States that is equipped for recording boundary layer param-\neters. Two 10-cm Doppler radars on a 41-km baseline provide unique capabili4\nties for recording atmospheric circulations both in precipitating weather\nsystems and in the optically clear boundary layer. A comprehensive range of\ninstrumentation for measuring parameters of both in-cloud and Loud-to-ground\nlightning has been brought to a high peak of refinement so that distributions\nof wind, water substance, and lightning can be recorded contemporaneously, and\ntheir interaction examined. A program of storm observing is conducted annu-\nally during the spring season, and typically involves about 20 different\norganizations.\nThrough numerous relationships with other government agencies and univer-\nsities, NSSL constitutes a resource for severe-storm data examined by re-\nsearchers around the country and overseas. NSSL also participates in worthy\nprojects outside Oklahoma. During FY 1985, NSSL staff participated in experi-\nments involving lightning strikes to aircraft near Wallops Island, Va., as-\nsisted in interpreting Doppler radar returns from orographic thunderstorms\nduring experiments in New Mexico, consulted in a multi-agency program on avia-\ntion safety at Memphis, Tenn., and had a major role in the multi-agency Pre-\nliminary Regional Experiment for Stormscale Operational and Research Meteorol-\nogy (PRE-STORM) during spring 1985. A major effort in the Laboratory is\ndirected toward establishing an effective national weather radar network for\nthe late 1980s and beyond, in support of the NEXRAD Joint System Program\nOffice, Silver Spring, Md.\nIn all these activities, the Laboratory cooperates with a host of other\ncapably staffed organizations around our country.\nMETEOROLOGICAL RESEARCH\nThe Meteorological Research Group seeks to improve thunderstorm forecast\nand warning capabilities by developing conceptual, numerical, and laboratory\nmodels of major thunderstorm phenomena and of the prestorm atmosphere.\nAnalysis and interpretation of storm flow fields expand our understanding of\nexternal and internal forcing, thermodynamics, cloud physics, electrification,\nand cloud dynamics, which contribute to intense thunderstorms and their attend-\nant phenomena. Subsets of the group objective are addressed by two projects:\nModeling and Dynamics, and Storm Evolution and Analysis.\n124","Accomplishments FY 1985\nTORNADIC STORMS\nTheoretical studies of storm rotation, when combined with Doppler radar\nand storm intercept information, enhance understanding of tornadic thunder-\nstorms. It was established that veering of the storm-relative environmental\nwinds with height (i.e., storm-relative streamwise vorticity in the environH\nment) causes updrafts (downdrafts) in supercell storms to rotate cyclonically\n(anticyclonically) on average. Also obtained from linear theory was a formula\nfor the correlation coefficient between vertical vorticity and vertical veloc-\nity in terms of storm motion, environmental winds, and the growth rate and\nhorizontal scale of convection.\nA model of Beltrami flow, in which vorticity is everywhere parallel to\nvelocity, was initialized to provide insights into the pressure field around a\nrotating updraft. As an exact solution of the Euler equations of motion, the\nBeltrami model serves as a test case for conceptual models that \"define\" main\nfeatures of dynamic pressure fields around updrafts. It also explains why\nthe\nmesolow at the Earth's surface is often observed to be several kilometers away\nfrom the circulation center in mesocyclones, and may help to explain the\ncharacteristic size and rotation rate of mesocyclones. Several results from\nlinear theory are also applicable when nonlinear effects are included.\nObservational data also play a major role in our understanding of the\ngeneration and intensification of vertical vorticity within severe thunder-\nstorms. Studies of several major tornadic storms during the past decade sup-\nport recent numerical simulations showing that production of vertical vortic-\nity begins at the very roots of an updraft as horizontal vorticity in low-\naltitude inflow regions is tilted toward the vertical. Then, as the flow\npasses through the updraft, the tilted vorticity and preexisting vertical\nvorticity are amplified by convergence to create the tornado parental circula-\ntion (mesocyclone). The low-altitude mesocyclone intensification that heralds\ntornadogenesis seems to result from interaction between spreading rainy\ndowndraft air and inflow air from the storm's right flank. Vertical vorticity\nis amplified by surges of convergence in the region of interactions. Rear\ndowndrafts, which develop at approximately the time of tornadogenesis, do not\ntransport significant vorticity; rather, their divergent character reduces\nvertical vorticity. Rear downdraft formation reverses the horizontal gradient\nof the vertical wind across the low-level mesocyclone and increases vorticity\nNSSL\ngeneration by twisting within the mesocyclone; but the generation rate is less\nthan half the amplification rate by convergence. Thus, tornadoes are most\nlikely to be triggered by the vorticity amplification that follows from outh\nflow-inflow interaction. During dissipation, updrafts and rainy downdrafts\nweaken, and rear downdraft air fills the mesocyclone. Vertical vorticity\nrapidly dissipates as air diverges near the ground, and the association\nbetween the mesocyclone and updrafts ends.\nThe retrieval of pressure and buoyancy information from the basic three-\ndimensional wind field is improving our understanding of dynamic forcing\nwithin severe thunderstorms. For example, the structure and evolution of the\nDel City, Okla., tornadic storm of 20 May 1977 were clarified through an in-\nvestigation into coevolving structure of velocity, pressure, and buoyancy.\nThe pressure field near the storm updraft includes higher pressure on the up-\n125","shear side and lower pressure on the downshear side. This orientation of prese\nsure centers rotates with the shear vector with height. The buoyancy distribu-\ntion in general shows warm updrafts and cool downdrafts, and a potential rela-\ntion between low-level vertical vorticity production and horizontal buoyancy\ngradients.\nOn rare occasions, a tornadic storm that produces an unusually large and\nintense tornado is positioned close to an NSSL Doppler radar. In such situa-\ntions, exceptional details about the radar reflectivity and Doppler velocity\nsignatures in the vicinity of the tornado can be obtained. The storm that\nproduced the violent (F4) Binger, Okla., tornado on 22 May 1981 was such a\nstorm. During a portion of the tornado's lifetime, high pulse repetition\nfrequency (PRF) measurements were made by NSSL's Norman Doppler radar; this\nspecial radar channel permits unambiguous velocities up to +91 m s-1 to be\nmeasured within the radar sampling volume. Analyses of the skirts of the\nDoppler velocity spectra revealed wind speeds of 90 m s-1 within the tornado.\nUsing the normal PRF (+35 m s-1) with the NSSL Doppler radars along with\nthe pulse pair processer does not permit examination of the Doppler velocity\nspectrum; instead, only the mean velocity in the sampling volume is available.\nHowever, a large and/or intense tornado produces a unique tornadic vortex\nsignature (TVS) among the mean Doppler velocity values as the radar scans past\nthe tornado. The TVS associated with the Binger tornado had unprecedented\nvertical extent--extending from the ground to within about 1 km of storm top.\nColocated with the TVS was a significant reflectivity minimum that became a\nweak echo hole at middle altitudes. The diameter of the minimum was ~750 m\nnear cloud base and gradually increased to -2 km at 9 km elevation. Calcula-\ntions for microphysical retrieval (see Microphysical Processes below) led to\nthe speculation that low reflectivities in a narrow tubehlike region were due\nto strong tangential velocities that prevented graupel from entering the\ntornado. This hypothesis is being tested with a finely resolving numerical\nmodel.\nDirect observation of tornadoes is another means by which understanding\nof tornadic storms is achieved. A portable instrument, TOTO (TOtable Tornado\nObservatory), was first developed in the Wave Propagation Laboratory to make\ndirect measurements of meteorological variables in tornadoes. Measurements of\nwind speed and direction, temperature, and pressure were made with this device\nnear tornadoes and beneath a rotating wall cloud. Data from damage surveys\nand Doppler radar are used in conjunction with TOTO measurements to obtain\nestimates of wind speeds in and near tornadoes. On 29 April 1985 an NSSL\nintercept team successfully deployed TOTO in the path of a tornado for the\nfirst time. Subsequent damage surveys revealed that the tornado was of minor\nintensity (FO classification) and that TOTO was located near the edge of the\ndamage path. Wind speeds of 30 m S-1 and a pressure drop of 1 mb in 1 S were\nrecorded with the tornado, and a pressure fall of 5 mb in 2 min with the meso-\ncyclone. However, wind tunnel tests and recent calibrations suggest some un\ncertainty in measurements of significant variations over such short periods.\nOne channel of NSSL's Norman Doppler radar is able to measure large un-\nambiguous velocities (+91 m superscript(1), making possible nonaliased velocity spectra\nfor sample volumes that include tornadoes. From spectral skirts, the maximum\nsampled velocity components were inferred as tornado wind speeds. A moderate\ntornado (F2 damage) in 1977 produced winds of 65 m s- 1 and the violent Binger\n126","tornado (F4 damage) in 1981 was associated with winds of 90 m S 1 Special\nanalysis methods are required to deduce accurately the velocities of tornado\ntargets whose distance renders them small compared with the radar beam.\nTHUNDERSTORM EVOLUTION AND STRUCTURE\nRadar observations, both conventional and Doppler, are continuing to pro-\nvide important information concerning the evolution and structure of convec-\ntive systems. The mechanisms whereby intense convection was maintained on the\nleading edge of a large squall line occurring on 19 May 1977 were examined.\nObservations revealed that at certain locations along the line new convection\nformed in short shower lines that were perpendicular to the principal squall\nline. Showers within the short lines, initiated by convergence not connected\nwith outflow boundaries, sustained convection in the most intense portion of\nthe squall line.\nThe characteristic lifetimes of particular thunderstorm features are\nimportant to operational meteorologists and to those engaged in aviation activ-\nities. A data set obtained on 19 June 1980 shows reflectivity core growth\nrates of 4 to 5 dBZ min and updraft growth rates of 3 to 7 m s 1 . Typical\ncells persisted 40 to 60 min. A related experiment, with important implica-\ntions for scanning strategies with operational radars in NEXRAD, investigated\nthe influence of data resolution on automated storm analysis and tracking\nalgorithms. Results indicate that interlacing of consecutive volume scans\n(i.e., odd-numbered tilt elevations from one data collection are mingled with\neven-numbered tilt elevations from the next collection) produces a gain in the\ndetectability and predictability of severe weather phenomena, because the\ncollection interval for each scan is reduced significantly.\nOther investigations of the structure and evolution of severe thunder-\nstorms continued. A storm on 19 June 1980 slowly evolved from a multicellular\nstate into a supercell storm, owing to the formation of a large region of\n\"background updraft\" in which individual cells were represented by updraft\nperturbations. As the storm intensified, individual perturbations (updraft\nand reflectivity) became more difficult to identify. In the cell's reference\nframe, environmental vorticity was not significantly streamwise and, hence,\nindividual updraft perturbations did not acquire strong rotation. However,\nthe larger scale region of background updraft moved to the right of the indi-\nvidual cells, and in this reference frame there was an appreciable streamwise\nNSSL\ncomponent of vorticity. Thus, the supercell structure and the presence of\nmesocyclones in the 19 June storm were attributed to the development and\nmotion of the background updraft region.\nScale interactions are prominently exposed in data sets collected on 26\nApril 1984. During the afternoon, isolated supercell storms formed and prom\nduced weak tornadoes; these were followed by formation of a solid squall line\nduring the night. Violent tornadoes occurred when breaks developed within the\nline. It seems likely that an approaching shortwave trough aloft altered the\nmesoscale environment, creating greater instability and a vertical wind shear\nprofile more favorable for tornadoes.\nA study of mesocyclone evolution, downbursts, and the differential motion\nof mesocyclones occurring in the Lahoma and Orienta storms of 2 May 1979 was\n127","completed. As in many other cases, mesovortex formation and intensification\nseem tied to the tilting of horizontal vorticity and the subsequent amplifica-\ntion of tilted vorticity by convergence. Periodic regeneration of meso-\ncyclones corresponded with updraft pulsations within background regions, while\nnew mesocyclones developed as new updrafts formed along gust fronts. Of two\ndownbursts, one seemed to be triggered by heavy water loading (radar reflectiv-\nities >55 dBZ) ; the second downburst involved weak reflectivity (<45 dBZ) but\nwas probably enhanced by the entrainment of potentially cold environmental air\nat higher levels. Principal mesocyclones within the two coexisting storms\ntended to approach and rotate cyclonically around each other. Observed rota-\ntion rates of 60-100° n-1 are in approximate agreement with computed value\nfrom a simple model for two interacting potential vortices.\nMICROPHYSICAL PROCESSES IN STORMS\nDocumentation of numerical models for identifying microphysical processes\nin storms was completed. The work proceeds from description of the motion\nfield by Doppler radar in three space dimensions and in time. Microphysical\nretrieval is applicable to studies of thunderstorm dynamics, microphysics, and\nelectrification. Future efforts to initialize a dynamic cloud model with real\ndata and to evaluate weather modification experiments will rely heavily on\nsuch a method.\nA study of the sensitivity of microphysical output to the model represen-\ntation of microphysical processes is being documented. Accuracy of the model\noutput is most strongly dependent upon the formulations of warm cloud and hail\nprocesses and on the detail represented in the hail size distribution.\nThe microphysical retrieval model was applied to several types of deep\nmoist convection. Relationships among the airflow, electrification, and cloud\nand precipitation development in an isolated New Mexico mountain thunderstorm\nare being studied with single Doppler radar and sailplane data and a one-\ndimensional cloud model. Non-inductive charge transfer accompanying collision\nand separation of ice crystals and riming graupel is calculated by the model.\nTotal space charge, accumulated by the nonginductive ice-ice mechanism plaus-\nibly explains the observed lightning flash rate in this storm.\nDiagnosis of the newly developed dynamic and microphysical retrieval\nmodels can be rigorously verified and extended through abundant in situ air-\ncraft measurements made in New Mexico during the summer of 1984. Preliminary\nanalyses of storm morphology began, using highly resolving data from four\nDoppler radars, three aircraft, and a number of electric field and charge\nmeasurement instruments.\nThe thermal and microphysical structure of an African squall line was\nanalyzed using dual Doppler derived airflow and a two-dimensional version of\nNSSL's microphysical retrieval model. This study, in collaboration with\nFrench scientists at the Centre de Recherches en Physique de 1'Environnement\nTerrestre et Planetaire, provides expanded knowledge of squall line structure\nand permits a comparison of the performance of contrasting diagnostic methods.\n128","MESOSCALE MODELING\nSome forecasters have noted that weak frontal boundaries on the elevated\nterrain of the Texas Panhandle and western Kansas are favored sites for growth\nof disturbances. Growth seems to be synchronized with afternoon heating of\nhigh terrain; a typical disturbance resembles a thermal depression located on\nthe front. The net result is a backing of winds in the moist air eastward\nfrom the low center, and convergence is focused northeast of the disturbance.\nThis northeastward location is thus a favorable area for severe thunderstorm\ndevelopment.\nIn collaboration with the Cooperative Institute for Mesoscale Meteorolog-\nical Studies (CIMMS), a mesoscale model was formulated to address this and\nother problems. In the first comprehensive study, the model was initialized\nwith a weak front and moderate southerly flow. The bottom (sloping) terrain\nwas heated with a variable rate, decreasing eastward. The solution, 4 h into\nthe simulation, indicates development of a vortex, backing winds in the east,\nand convergent tendencies northeast of the low. An intriguing feature of this\ndevelopment is the tendency of the vertical wind shear in this area to exhibit\nlarge directional shears below 700 mb, characteristic of tornado proximity\nsoundings. The 850-mb fields at 8 h include increased vorticity values and\nfalling geopotential tendencies toward the south-southwest of the low\nposition.\nFORECASTS AND WARNINGS\nMuch of NSSL's research related to improved forecasts and warnings in-\nvolves preparation for the implementation of the next-generation Doppler\nweather radar system (NEXRAD). The search for single Doppler signatures for\ncertain weather phenomena continued. Currently, wind and reflectivity fields\nfrom a simulated hurricane model are being used to construct Doppler radar\nsignatures for these storms. We need to learn how changes in hurricane intense\nity are manifested in the radar observations.\nA joint project (DOPLIGHT) with the National Weather Service (NWS) Fore-\ncast Office at Oklahoma City completed its second year. Single Doppler veloc-\nity data with cloud-to-ground strike locations are transmitted in real-time to\nthe forecast office. An NWS forecaster coordinates display selection from the\nNSSL radar site. The real-time Doppler velocity signatures are incorporated\nNSSL\ninto the forecast office's weather warning decisions.\nThe attenuation of radar signals at short wavelengths has import for the\ndetection of severe weather phenomena. A comparison of reflectivity patterns\nat 5 and 10 cm wavelength for the 2 May 1979 data set illustrates the problems\nthat can occur. When the Orienta and Lahoma storms became radially aligned\nwith respect to a 5-cm radar, signal attenuation exceeded 30 dB. The attenua-\ntion distorted the reflectivity structure of the Lahoma storm as observed by a\n5-cm radar, and the expected association of mesocyclone and reflectivity\nmaxima was not evident; i.e., the mesocyclone appeared in the weak reflective\nity gradient on the left flank of the storm instead of the right flank. A\nforecaster would not have concluded this to be a hazardous storm.\n129","NSSL has been aiding the National Weather Service in evaluating new\nDoppler radars at Montgomery, Ala., and Marseilles, Ill. The Montgomery 5-cm\nradar seems effective for ranges <130 km. The radar was found to be limited\nby a small velocity measurement interval and problems in velocity interpreta-\ntion, but a net improvement was nevertheless realized in local warning\ncapability.\nDATA ACQUISITION AND PROCESSING\nWe constantly search for better data acquisition methods and improved\ntechniques for analyzing data. The utility of surface observations in\nmultiple-Doppler objective analysis schemes is related to distance. Storms\nscanned by radars are typically 50 km or more distant. In this situation the\nobservations are no lower than 0.25 km AGL with scanning at 0° elevation.\nThis leaves the researcher with the choice of establishing the lowest level of\nthe wind field analysis at the height of the lowest scan or using downward\nextrapolation to obtain an estimate at ground level. Downward extrapolation\nmay suffer in accuracy since tall-tower data show that winds over large re-\ngions in the lowest half kilometer of a thunderstorm turn substantially clock-\nwise with height. Since vertical velocity determination requires accurate\nboundary conditions, a method of analysis was developed for drawing on both\nDoppler radar and surface data to produce a more representative surface wind\nfield.\nA recent study showed that errors in wind field analyses can have large,\nfar-reaching consequences, but also that these effects can be minimized by\ncareful selection of analysis techniques.\nAirborne Doppler radar can collect data on target storms that are quite\nwidely dispersed. However, the relatively long time required to sample an\nindividual storm in detail, particularly with a single aircraft, and the ampli-\nfication of statistical uncertainty in radial velocity estimates when\nCartesian wind components are derived, suggest that errors in wind fields\nderived from airborne Dopple radar measurements would exceed those from a\nground-based radar network better located to observe the same storm. Error\ndistributions for two analysis methods (termed Overdetermined and Direct\nmethods) were applied to data collected on a sea-breeze-induced storm in\nwestern Florida on 28 July 1982. Application of the direct solution not in-\nvolving the continuity equation, and the overdetermined dual Doppler method,\nwhich requires use of the continuity equation, produced similar fields.\nHowever, since the magnitudes of all errors are unknown and the response of\neach method to errors is different, further study is required.\nAn extremely important component of the 1985 PRE-STORM Program was acquis-\nition of rawinsonde data with 1.5 to 3 h time resolution from 12 supplemental\nsites and 15 National Weather Service sites. A routine was developed at NSSL\nto bring data from the supplemental sites to the PRE-STORM control center for\nprocessing in near-real time. The processed data were then transmitted\nthrough the national system by the NWS System for Automation of Field Opera-\ntions and Services (AFOS). Users of AFOS thus had unprecedented access to\nupper-air data with fine temporal and spatial resolution.\n130","Along a related line, objective analysis algorithms are being developed\nto read and analyze mesoscale rawinsonde data. The analysis package will be\nused to produce fields suitable for use in NSSL's version of the Warner-Anthes\nmesoscale numerical model.\nPlans FY 1986\nThere will be a substantial effort to integrate observations with\ntheoretical investigations and mesoscale numerical modeling. Among\nspecific topics to be examined are cyclogenesis on mesocyclone scales\nand larger multi-dimensional cloud modeling, and model initialization\nand verification studies. These studies will be pursued in cooperation\nwith CIMMS.\nAn initialization package will be developed, suitable for interfacing\nthe objective analysis package with NSSL's mesoscale model.\nProcessing of rawinsonde data from all 27 PRE-STORM sites will be\ncompleted.\nA number of studies will begin, using data collected during the 1985\nPRE-STORM program:\nA case study of scale interaction on 12 May 1985.\nMesoscale modeling experiments utilizing multi-release rawinsonde data\nas initial conditions for two excellent situations (10-11 May and 10-11\nJune 1985) .\nExtensive studies of cell-storm and storm-environment interaction for\nunderstanding mesoscale convective system morphology and evolution.\nGeneration of a statistical data base for algorithm development to aid\ndesign of sensing networks.\nAnalysis of the following storm cases will continue:\nThunderstorm Research International Project (TRIP) 1984 case.\nNSSL\n22 May 1981 Binger storm, for microphysics and dynamics; 19 June 1980\nfor reflectivity and electrical data.\nDocumentation of the following studies will be completed:\nThe sensitivity of microphysically retrieved variables to details of\nthe microphysical formulation.\nSevere storms on 8 June 1974, 9 May 1977, and 6 June 1979.\nTraining manual for interpretation of single-Doppler color displays.\nCompilation of mesocyclone statistics.\n131","Among the case studies to be initiated (other than PRE-STORM cases) are\nthe following:\nMicrophysical retrieval/electrification on 19 June 1980.\nDynamic retrieval on 19 May 1977.\nDOPPLER RADAR AND STORM ELECTRICITY RESEARCH\nNSSL has major facilities to observe electrical and kinematical processes\ncontemporaneously with precipitation phenomena. The objectives of Doppler\nRadar and Storm Electricity Research (DRASER) include (1) determining relation-\nships between processes of lightning, thermodynamics, and precipitation in\nthunderstorms in order to develop improved indicators of thunderstorm severity\nand hazards; (2) developing and refining remote-sensing techniques for locat-\ning, tracking, and predicting thunderstorms and their attendant hazards; (3)\ndefining lightning and kinematic characteristics of storms for inputs into\nengineering criteria for hazards to aircraft and ground facilities, and into\nmodels used in environmental studies; (4) providing ground truth and support-\nive data for development of new instrumentation and refinement of\nobservational techniques.\nThese objectives are addressed through both theoretical and observational\nstudies. The Doppler Radar Group focuses its efforts on interpretation of\nprestorm and stormy weather phenomena, using data from Doppler radar as well\nas a multitude of other sensors. The Storm Electricity Group concentrates its\nanalyses on data simultaneously obtained with Doppler radar and our many storm\nelectricity sensors.\nAccomplishments FY 1985\nDOPPLER RADAR\nPrestorm Environment and Storm Initiation\nWe explored means for diagnosing changes in temperature profiles from\nsingle Doppler wind data. The geostrophic wind, and hence the thermal wind,\nis estimated by solving the equations of motion for the Doppler-defined fields\nof actual wind in various layers, with an assumption or two about vorticity.\nHorizontal temperature advection is then estimated from the thermal wind.\nTemperature change due to subsidence or rising motion is computed from averH\naged vertical Doppler velocity and initial temperature profile. A boundary\nlayer model was incorporated to account for diabatic heating and vertical\nmixing. Tests performed on actual data were used to assess the accuracy of\nthe method. The results with radar data from clear air are interesting and\nwarrant continued investigation. Horizontal temperature advection appears to\nbe the most uncertain element in the model.\n132","Comparison of divergence measured with two Doppler radars and divergence\nestimated by volume-velocity processing (VVP) from a single Doppler radar\nshowed that agreement is much better when the radar data are filtered. This\nis because small-scale nonlinearities that bias the VVP divergence are removed.\nAnalysis of the 17 May 1981 data revealed areas of convergent flow near and\nahead of the dry line. The variance of radial velocities from a single radar\nis not well related to the intensity of convergence and convective clusters\n(see NSSL Annual Report, 1984).\nA Uniform Wind Algorithm was used to derive the wind field in the vicin-\nity of a front, from single Doppler radar data. The derived wind was shown to\nbe consistent with rawinsonde wind data. Furthermore, the measured slope of\nthe front is consistent with the average divergence, deformation, and vertical\nair motion derived from Doppler VAD (velocity-azimuth display) analyses.\nData from a solar eclipse and other clear days revealed an effect of in-\nsolation and ground wetness on radar reflectivity near the ground. The re-\nsults are consistent with expected relations, thus warranting more quantita-\ntive comparisons.\nLidar Investigation of Storm Environments\nFeatures of special interest in windfields derived from Doppler lidar\ndata were waves and vortices at the leading edge of a gust front marked by an\narcus cloud formation and clearly delineated wind shifts in cloudless regions.\nAlso seen by the Doppler lidar were clear air flows just below the base\nand sides of an isolated cumulus congestus circumnavigated by a NASA aircraft.\nAnalyses of winds above cloud base suggested that the cloud was entraining\nenvironmental air, therefore causing a net convergence of environmental air\ninto the cloud above its base.\nSolitary Wave Research\nThe steady-state solitary wave solution of the Benjamin-Davis-Ono (BDO)\nequation in a two-layer deep fluid was compared with Doppler radar and tower\nobservations of a boundary layer solitary wave. The results indicated that\nthe BDO theory provides an adequate explanation for this observed largeHampli-\nNSSL\ntude solitary wave. The BDO theory was extended to the case in which the\nupper layer has a weak stable stratification. The extended theory showed that\nthe solitary wave amplitude should decrease with time, owing to upward radia-\ntion of wave energy, a loss not present when the upper troposphere is\nneutrally stratified. The theory of Maslowe and Redekopp was applied to esti-\nmate the solitary wave attenuation; theoretical results suggest an attenuation\nrate about twice that observed. We also initiated a joint research project\nwith the Australian National University (ANU) to make cooperative observations\nwith ANU's microbarograph array and NSSL's Doppler radars and tall-tower in-\nstruments. Simultaneous data were collected on at least two well-defined wave\npackets that propagated through the network during the 1985 PRE-STORM period.\n133","Wind Profilers (50/405 MHz)\nIn cooperation with ERL's Wave Propagation Laboratory and the University\nof Oklahoma, a 50-MHz wind-profiling radar was installed on a gently sloping\nhillside about 30 km SSW of NSSL. The radar began preliminary wind observa-\ntions in mid-May and has operated automatically since. The wind fields ob-\nserved with radar are being compared with wind data from rawinsondes launched\nby the Weather Service Forecast Office in Oklahoma City. WPL and NSSL are\nalso cooperating to test wind-profiling capabilities of a 405-MHz radar. (See\nFacilities Development section, below.)\nDoppler radar wind profiling within storms was studied. A limited data\nset acquired over 2 days showed comparable differences between each of the\nthree pairs defined by single radar, two radars, and rawinsonde.\nA real-time VAD program was set up to support the DOPLOON (Doppler-\nballoon) project (intended to automate balloon tracking for determination of\nwinds by Doppler radar). Refinements of the computer program were made for\nimproved acquisition and tracking of a target balloon. From the limited num-\nber of experiments we concluded that DOPLOON winds compare well with\nrawinsonde observations.\nClear-Air Reflectivity\nA few data sets of clear-air echoes were collected after winter cold\npassages. Measured values of the structure constant were 10 14 to\nfront\n2/\n10- 15 m , which were, also the values calculated from theory, using rawin-\n3\nsonde data and assumed eddy dissipation rates as inputs. However, similar\ncalculations (i.e., assuming turbulent breakdown of shear layers) for 27 May\n1983 underestimate the Cn 2 values by one to two orders of magnitude. On the\nother hand, the theory based on temperature fluxes in a mixed layer gave re-\nsults in good agreement with observations. But vertical profiles of reflectiv-\nity on that day can also be accounted for with typical distributions of in-\nsects in the atmosphere.\nDowndrafts and Gust Fronts\nThunderstorm downdrafts (downbursts) in Oklahoma can be highly asymmet-\nric, with shear along the maximum shear axis more than five times the shear\nalong the minimum shear axis. Furthermore, downbursts in Oklahoma are signifi-\ncantly different from those observed around Denver, Colo., during the Joint\nAirport Weather Studies (JAWS). For instance, the majority observed during\nJAWS were \"dry\" with little or no rain that reached the surface; they were\ndriven by evaporative cooling below cloud base, which occurred when precipita-\ntion fell into a deep, dry, nearly adiabatic boundary layer. Lower cloud\nbases, and a moister and slightly more stable boundary layer reduce the in-\ncidence of downbursts in the Oklahoma area. Instead, observed Oklahoma down-\nbursts were associated with intense convective storms, and the initiation\nmechanisms probably include low-level melting and evaporation of precipita-\ntion, precipitation loading at low levels, and evaporational cooling at middle\nlevels due to entrainment of dry air.\n134","Comparison of surface-measured horizontal shear and that measured by\nDoppler radar was completed. For 41 comparisons of gust front shear, shear\nmeasured by Doppler radar (at heights 50-600 m) averaged 1.6 times that\nmeasured at the surface. Conclusions were that the Doppler radar is able to\nestimate shears that may occur below the radar beam, and in fact may over-\nestimate those shears.\nPolarization Studies\nNSSL's engineering group installed a fast polarization switch on the NSSL\nDoppler radar at Cimarron, and first data collection began in the spring of\n1985. Theoretical investigation of polarization parameters produced the\nfollowing conclusions: (1) Acquisition time for differential reflectivity\n(ZDR) can be significantly reduced by simultaneously sampling the vertical and\nhorizontal electric fields. (2) Such a scheme does not compromise spectral\nmoment estimation and allows scan rates of 3 rpm if correlation between simul-\ntaneously received horizontally and vertically polarized echoes is better than\n0.995. A theoretical investigation of all the factors that contribute to the\ndecorrelation established that simultaneous sampling does indeed reduce acquis-\nition time in rain media. A scheme for Z DR measurement was suggested which\nuses +45° and -45° polarized transmissions alternately with simultaneous\nreception of horizontal and vertical signals to compensate for bias error due\nto propagation. Further, a method of nearly eliminating bias error due to\nreceiver mismatch was suggested.\nWe described a new method based on differential phase ODR the dif-\nference in phase shift accompanying propagation of vertically and horizontally\npolarized waves) to estimate rainfall rate. We showed that differential phase\nis relatively insensitive to drop size distribution variations and thus can\nyield more accurate estimates than methods based on ZDR. Standard errors in\nODR cause large inaccuracies at low rain rate (<30 mm h thus limiting its\nusefulness to estimating higher, potentially more severe rain rates. It was\nalso shown that ODR can be used as a third remote measurable to determine a\nthreenparameter drop size distribution.\nEnhanced Observing Capabilities\nWe found additional hardware (more memory, parallel interfaces) for the\nNSSL\nAP120B array processor to facilitate real-time spectral processing. A\nFPS\nprogram was written for the Perkin-Elmer data processor to use the array proc-\nessor for computing Doppler spectra. We developed a program to facilitate\nprocessing of raw Doppler tapes. This program lists housekeeping, skips\nrecords, and searches for time, elevation angle, azimuth angle or step number,\netc., so that the data can be inventoried and processed quickly.\nA statistical classification approach to editing clear-air radar data was\nstudied. Echo-power- and noise-biased spectral width estimates were selected\nfor use as classification variables. The power and width space was divided\ninto four regions for clutter, meteorological data, outliers, and noise.\nBoundaries for the regions were drawn by a mixture of theoretical and observa-\ntional considerations. An application of the classification to PRE-STORM data\nfor 22 April 1981 showed good performance.\n135","A method for whitening sidelobes of linear array antennas was developed.\nThe method requires switching of a small number of elements (2 to 4) and uses\nan unequal spacing between them.\nAlgorithms for Next-Generation Weather Radar (NEXRAD)\nWe completed the development and analysis of three NEXRAD algorithms.\nThe first algorithm is a sectorized uniform wind algorithm using single\nDoppler data. It requires evaluation of azimuthal derivatives of radial veloc-\nity to estimate the transverse wind components. For a uniform wind, the rela-\ntionship is exact. Application of this technique to Doppler data to estimate\nwind fields in the vicinity of frontal boundaries and in uniform wind situa-\ntions showed good results. With the help of this algorithm, it will be pos-\nsible to locate frontal boundaries with resolution much superior to that\nafforded by surface stations. These boundaries often trigger severe storm\nformation.\nThe NEXRAD Tornado Vortex Signature (TVS) algorithm is similar to the\nNEXRAD Mesocyclone algorithm. Its purpose is to search for regions of very\nhigh cyclonic shear associated with TVSs. In testing on eight tornadic\nthunderstorm cases the algorithm detected 84% of the actual number of TVS\nfeatures, and there were no false alarms other than those caused by dealiasing\nproblems. It was observed that all violent tornadoes produce a TVS signature;\nthus our algorithm should enhance the tornado warning process.\nTesting of the divergence algorithm continued; comparison of observed\ndivergence and fluxes showed general quantitative agreement with those generH\nated by a simple updraft model, having the observed diameter and an estimated\nupdraft speed. An increase in estimated divergence precedes a reflectivity\nbuildup by 5-10 minutes.\nA fourth NEXRAD algorithm being developed is meant to detect and trace\ngust fronts.\nSTORM ELECTRICITY\nLighting Strikes to Aircraft\nResults of the analysis of data obtained during low-altitude storm\npenetrations by the NASA F106-B research airplane included the following:\nThe probability of direct strikes to the airplane increases both during\nthe decaying stage of storm cells and with decreasing natural lightning\nflashing rates.\nAt low altitude within the storm cell the airplane can either trigger a\nstrike to itself or intercept an existing flash; strikes at high\naltitude are nearly always triggered.\nThe directions of channel development inferred from lightning radar\necho propagation agree with those determined from actual television\n136","(TV) recordings of the same flashes that show their propagation, a\nphysically reasonable expectation now confirmed.\nPositive Cloud-to-Ground Lightning and Synoptic-Scale Conditions\nWe analyzed synoptic conditions for 13 May 1983 when an unusual number of\npositive cloud-to-ground (+CG) flashes occurred. Synoptic-scale analyses were\nperformed in cooperation with NASA/ Marshall Space Flight Center. The occur#\nrence of +CG flashes does not appear to have been uniquely related to sea\nlevel pressure tendencies, moisture convergence, or vertical temperature pro-\nfiles, but may have been linked to vertical shear in the horizontal wind.\nFacility Upgrades and New Instrument Development\nModification to our very-high-frequency (VHF) lightning-mapping system\nwas completed, to allow mapping of the entire hemisphere continuously with\ndata collected at rates of 16,000 lightning impulses per second. This modifie\ncation was tested and calibrated and then used to acquire data during the\nspring program.\nFor the PRE-STORM program, coverage of our network for locating lightning\nground strikes was expanded to Kansas and southern Nebraska, and to contiguous\nparts of Colorado, Arkansas, Missouri, and Colorado.\nThe storm electricity mobile laboratory and the vehicles used in NSSL's\nstorm intercept program were deployed in highly successful coordination, which\nwill be continued.\nWe designed and fabricated a new instrument to measure the velocity of\nreturn strokes propagating between the ground and the cloud. Optical sensing\nelements, placed behind a 35 mm camera lens system, are coupled to high-speed\ncircuits to record the optical waveform in eight narrow horizontal slits along\nthe channel. We hope that our instrument will eventually replace the very\nexpensive, cumbersome, and low-data-rate cameras now used to estimate return\nstroke velocity. Uses of the data will include determination of currents and\nother physical features of return stroke channels. We hope to resolve the\nquestion raised several years ago as to whether lightning currents and veloci-\nties in Great Plains severe thunderstorms are different from those observed in\nNSSL\nFlorida tropical storms.\nContinuing Currents in Intracloud Lightning Flashes\nAnalysis of data from our vertically pointing Doppler radar and the VHF\nlightningHmapping system for about 70 intracloud flashes showed horizontal\nprogression of the lightning through our observational areas, lightning echoes\ngenerally having intensities stronger than precipitation echoes seen at radar\nwavelength of 10 cm. The lightning echo in an intracloud flash is apparently\na result of a current surge that produces ionization detectable by radar. The\nlife cycle of these lightning echoes clearly shows thermal decay after the\ninitial ionization. Theoretically, decay of slow echoes could be related to\nlarge size of ionized channels or to continuous current. However, observa\"\n137","tional indications are that thermal decay is slowed by continuous current in\nthe intracloud channel. Continuous current in intracloud lightning has been\ninferred by others, but it was not known to be as frequent as our preliminary\nanalysis indicates. There are practical implications for this finding in the\narea of aviation hazards.\nLightning channels were observed to accelerate vertically immediately\nafter their formation. It seems probable that this acceleration is a combined\neffect of Earth's magnetic field and buoyancy acting on the hot plasma channel\nthrough which a current flows.\nUsing lightning as a tracer, we inferred vertical air velocities from\n#2.0 to 17.5 m S A1 The observations thus far suggest that lightning is\nusually within updraft regions.\nLightning and Storm Studies\nIn cooperation with NASA/Marshall Space Flight Center, we are analyzing\ncloud-to-ground activity during periods of several mesoscale convective\nsystems (MCSs).\nWe are seeking to evaluate the ratio of intracloud to cloud-to-ground\nlightning, to relate this to storm development and to apply it to use of cer-\ntain sensors in NWS operations.\nWe are in the final stage of preparation of an improved national climatol-\nogy of lightning strikes.\nA completed analysis verified that +CG flashes tend to have continuing\ncurrent in the return stroke channels.\nPlans FY 1986\nDOPPLER RADAR\nTo develop improved operational capabilities for forecasting the loca-\ntions and intensities of storms, we shall continue in-depth examinations\nof the PRE-STORM radar data with other data sources and theory.\nTo predict downdrafts and gust fronts, study of their origin and\nevolution will continue.\nStudies of advanced techniques to reduce velocity and range ambiguities\nin Doppler radar will be conducted.\nAspect dependency of Doppler spectrum width will be studied.\nThe wind-profiling capability of weather radars will be examined both\ntheoretically and experimentally. The accuracy of the 50HMz wind profiler\nwill be evaluated. Wind profiles derived from simple Doppler radar observa-\ntions within storm velocities will be examined. We shall continue to pursue\n138","the capabilities of Doppler radar to track reflecting balloons from which wind\nprofiles could be derived.\nNEXRAD algorithms for detection and tracking of hazardous weather will be\nimproved.\nWe will analyze our first polarization data obtained in the spring of\n1985 in order to determine the quality of rain rate estimates and the\ncapability to identify hydrometeors remotely in storms.\nA joint NSSL/Australian National University analysis of solitary wave\ndata will be conducted.\nSTORM ELECTRICITY\nPerform a side-by-side comparison of the two commercially available\ncloud-to-ground strike-locating systems (dependent upon installation of\nthe second system by its distributor) under funding from NWS.\nContinue our involvement with the National Interagency Coordinating Group\n(NICG) both in terms of coordinated research and as vice-chair of the\n1986 International Conference of Ground and Static Electricity.\nParticipate in the development of a National Plan for Lightning Data.\nParticipate in the planning and data analysis of a multi-agency program\nutilizing a least two instrumented airplanes to measure lightning strikes\nto aircraft.\nExpand the data base of the characteristics of positive cloud-to-ground\nflashes and their relationships with storm and environmental parameters.\nContinue to address the need for and uses of a satellite-based lightning\nmapping system.\nReplace the NSSL mobile laboratory, which is no longer reliable, and in-\ncrease the parameters that we record by adding meteorological sensors.\nAnalyze lighting channel plasma properties from dual radar observations\nNSSL\nof lightning, and continue development of software to analyze ground\nstrike data and VHF lightning-mapping data.\nAcquire additional measurements of return stroke velocities.\nComplete evaluation of +CG detection capability of the NSSL lightning\nstrike-locating system and study CG lightning evolution in mesoscale\nconvective systems.\n139","COMPUTER AND ENGINEERING SUPPORT\nAND DEVELOPMENT\nThis group develops techniques and equipment, maintains the NSSL observa-\ntional facilities, and supports the observational programs associated with the\nmeteorological research. The NSSL base facilities consist of two 10-cm meteor-\nological Doppler radars, a WSR-57 (surveillance radar), a tall (444 m) tower,\na 52-station surface network, an air traffic control facility, and equipment\nfor measuring electrical phenomena in the atmosphere. The group also provides\nengineering consulting to the NEXRAD/JSPO and engineering support to the\nInterim Operational Test Facility of NWS.\nAccomplishments FY 1985\nCOMPUTING AND DATA PROCESSING\nThe NSSL VAX 11/780 was installed and became operational. It consists of\n12 megabytes (Mb) of memory, 1778 Mb of disk storage, three magnetic tapes,\nand a RAMTEK color graphics workstation. The system is used for interactive\nediting of Doppler radar data and for editing and archiving of other NSSL-\ncollected data, and serves as a remote job entry link to the CDC 855/205 in\nGaithersburg, Md.\nA MICOM telecommunication system was installed. It provides communica-\ntion to the CDC 855/205 by means of two dedicated 9600-baud phone lines as\nwell as a multiplexor and electronic switch for interconnection of all NSSL\nterminals to the VAX, CDC/205, and to the NSSL PerkinHElmer computer connected\nwith the Norman Doppler radar.\nNSSL supplied data sets to these users:\nLassen Research\n(R. Lee)\nManton, Calif.\nMIT Lincoln Laboratories\n(J. Evans)\nLexington, Mass.\nNASA Goddard Space Flight Center\n(G. Heymsfield, R. Blackmer,\nGreenbelt, Maryland\nI. Hakkarinen)\nNational Weather Service\n(D. Devore)\nWeather Service Forecast Office\nOklahoma City, Okla.\nNational Weather Service\n(W. McGovern)\nTechniques Development Laboratory\nSilver Spring, Maryland\nPurdue University\n(D. Klingle)\nWest Lafayette, Indiana\nTexas Tech University\n(K. Mehta)\nLubbock, Texas\n140","(H. Bluestein, G. Byrd)\nUniversity of Oklahoma\nNorman, Okla.\nFACILITIES ENGINEERING\nThe Sperry Corporation established a ground-based facility for its air-\nborne Doppler radar developed for the commercial carrier market. Data from\nthe system were compared with data from the NSSL Norman Doppler to evaluate\nsystem performance. This was the third airborne Doppler radar system\nevaluated at NSSL.\nTransfer of quasi-real-time data from the Doppler radar at Norman to the\nWeather Service Forecast Office at Will Rogers Airport was done routinely\nduring the PRE-STORM program. These data proved useful to the duty forecaster\nand provided an opportunity for gradual technology transfer and examination of\nminimal Doppler radar products by the operations office.\nSome NSSL facilities, particularly the Norman Doppler radar, were main-\ntained operational from January into September in support of multiple pro-\ngrams: Winter Storm, during January through March, PRE-STORM from April\nthrough June, and Special Research during July and August. This schedule\nrepresented a substantial extension of the Laboratory's normal observational\nseason.\nSystems engineering for an antenna dual polarization capability on the\nNSSL Doppler radar at Cimarron (CIM) was completed, and routine operations\nbegan with the PRE-STORM program. Data were acquired for meteorological re-\nsearch, engineering evaluation, propagation studies, and real-signal\nstatistics.\nThe in-house research program to examine the feasibility of upper-air\nwind measurement by balloon tracking with a NEXRAD-type radar continued.\nExperiments to determine balloon cross section and radar system performance\nwere successful, and we are designing electronic circuits to facilitate auto-\nmatic balloon tracking.\nThe National Acid Deposition Assessment Program site operation continues\nsince its institution in 1983. Sample collection is both wet deposition (rain-\nfall) and dry deposition (dust) at a local farm. Sample pre-analysis consis-\nNSSL\nting of a pH and conductivity measurement is done at NSSL. Detailed composi-\ntion analysis is done at the Illinois State Water Survey.\nFACILITIES DEVELOPMENT\nLong-needed improvements in the CIM radar real-time display and data\nrecording were begun with the design and fabrication of a radar signal pre-\nprocessor and second-generation color display. Fabrication of the preproces-\nsor and display terminal was completed, and system software is being written.\nAn expanded data acquisition and recording terminal for the NSSL tall-\ntower facility was designed, built, and commissioned. Program demands in\n141","recent years have exceeded the capability of the original system placed in\nservice in the late sixties.\nWork began on the establishment of a 405-MHz Profiler at the NSSL. This\nis a joint program with WPL whereby NSSL is to build a steerable parabolic\nantenna system and WPL is to provide the transmit/receive terminal. A para-\nbolic reflector and positioner have been acquired from surplus and modified to\nsuit our needs. Current goals are to determine the suitability of the 75-cm\nwavelength for central Oklahoma applications and the electrical performance of\nthe parabolic antenna system.\nSystem engineering for a microwave data link between the NSSL Cimarron\nand Norman radars is complete. Hardware is scheduled for delivery in late\n1985. Initially the system will be an L-band simplex link consisting of a\ntransmitter at Cimarron, a repeater on the KTVY tower, and receiver at Norman.\nIt will carry the full data from Cimarron and interface to a remote display\nterminal and to the Perkin-Elmer 3242 computer terminal at Norman. Among\nother things, it will provide NSSL with the data needed to synthesize the\nobservations from two Doppler radars in real time.\nPlans FY 1986\nCOMPUTING AND DATA PROCESSING\nUpgrades to the VAX 11/780 will include the installation of a seven-track\ntape and/or an electrostatic plotter and laser printer. Graphics software now\noperational on the CDC 750 will be converted for use on the CDC 205 and the\nNSSL VAX. New graphics software will be designed to use unique features of\nthe RAMTEK color graphics system. Additional support will be given to scien-\ntists in the optimization of computer programs for use on the CDC 205.\nFACILITIES ENGINEERING\nThe microwave engineering phase of dual polarization development is\ncomplete. During FY 1986 we will complete a study of signal statistics\nand preliminary evaluation of meteorological utility. Initial data examina-\ntion indicates that the technique has good potential for meteorological re-\nsearch and we should proceed with the development of processing techniques and\nhardware needed to realize this potential.\nIt is planned to design and fabricate a microwave transmitter and re-\nceiver to service a vertical antenna at the Norman radar site. Data will\nbe recorded on a wideband analog recorder and processed through the\nNorman terminal. This will provide a vertical radar capability\nwithout conflict with the Norman radar.\nNSSL has need of a high-quality wide-bandwidth data distribution system\nin and around the central Laboratory. It is planned to establish a data\ndistribution network using fiber optics technology.\n142","The microwave portion of the Cimarron/Norman data link will be\nestablished in early FY 1986. The Cimarron radar interface is incorporated\ninto the radar preprocessor and display terminal for this system and will be\ncommissioned with this terminal in FY 1986. Development of remote data\nprocessing for analysis and display at Norman will continue.\nIt is planned to complete a 405-MHz antenna terminal and to begin\nexperimentation. A preliminary evaluation of the system should be\navailable by the end of FY 1986.\nNSSL\n143","","C. Gordon Little\nWAVE PROPAGATION LABORATORY\nDirector\nBoulder, Colorado\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nSEL\nWPL\nARL\nAL\nAOML\nGLERL\nGFDL\nNSSL\nPMEL\nNOAA's core mission of atmospheric and oceanic forecasts and warnings\nrequires that it observe the present states of the atmosphere and ocean in\norder to be able to predict their future states. Since both media are\nthree-dimensional, the observations must also be three-dimensional; moreover,\nthe data sets must adequately resolve spatial or temporal structures at least\nas small as those to be forecast.\nIn general, the denser the observational data set in space and time, the\nmore complete and accurate the services can be. Experience has shown that in\nsitu measurement methods, which require a sensor at each measurement location,\nare too expensive to be practical for anything but the largest scale phenomena.\nIn 1967, the Wave Propagation Laboratory (WPL) was set up to explore the\npossibility that remote sensors might provide the severalhorders-of magnitude\nimprovement in space/time density of observations required to predict or warn\nof smaller scale phenomena.\nIn summary, then, the WPL mission is to improve the Nation's geophysical\nWPL\nresearch and services, through the development, demonstration, and\ndissemination of cost-effective remote measurement systems. To achieve this\ngoal, WPL must successfully perform the following functions:\nDetailed theoretical and experimental studies of the interactions of\nacoustic and electromagnetic waves with the atmosphere or ocean, with\nparticular reference to the use of such interactions for remote-sensing\npurposes.\nDevelopment and experimental evaluation of new geophysical remote-sensing\nconcepts and systems.\n145","Application of the unique advantages of newly developed remote-sensing\ntechniques to atmospheric and oceanic research.\nImprovement of the Nation's atmospheric and oceanic research, and\nforecasting and warning services, through transfer of remote-sensing\ntechnology to others.\nBecause observational capability underlies essentially all geophysical\nresearch and services, WPL's research has broad impact. The following\npresentations give a brief rationale for the research programs, and summarize\nthe FY-1985 programs and FY-1986 plans. Where appropriate, the research tasks\nwithin each program are grouped according to meteorological scale.\nWEATHER OBSERVATION AND PREDICTION\nWPL's contributions to weather observation and prediction support NOAA's\nlargest and most important single service, namely, weather forecasts and\nwarnings. Such services are required on many space and time scales. WPL's\nremotesensing R&D program includes contributions on all scales from the\nmicrometeorological to the global.\nMICROMETEOROLOGICAL R&D\nResearch on micrometeorological processes in the atmospheric boundary\nlayer is important because these processes include the turbulent fluxes of\nheat, moisture, and momentum that change the dynamic and thermodynamic\nproperties of air masses. Remote sensors contribute uniquely to the research\nby providing the resolution and continuity in both space and time that are\nrequired to observe, monitor, understand, and predict these important boundary\nlayer processes. WPL has long led in the development and application of such\nsensors.\nAccomplishments FY 1985\nSENSOR DEVELOPMENT\nA technique for extracting second moments of the wind from measurements\nmade with multibeam monostatic sodars was developed and tested. The technique\nis based on theoretical evaluation of the effects of the spatial and temporal\nseparations on measurements obtained from the sodars.\nNew hardware and software for operating a four-axis Doppler sodar system\nin a simulated VAD mode were developed and tested. An experiment was\nconducted to determine if, as predicted by theory, this approach yields\ndependable values of stress in the lowest 500 m of the atmosphere.\n146","New software was developed to process and analyze Doppler lidar data from\nthe Brush Creek experiment of the Department of Energy's Atmospheric Studies\nin Complex Terrain (ASCOT) program. The software utilized spatial averaging\nand terrain gating techniques to generate contour plots of the radial flow\nfield.\nThe fifth and final phase of the Flatville, Ill., millimeter wave\npropagation experiment, sponsored by the Army Research Office, was completed.\nAmplitude, phase difference, and angular fluctuation data were taken at a\nrange of frequencies from 140 GHz to 230 GHz in clear air, rain, fog, and\nsnow, over the horizontal, 1.3 km path. The measurements are in the process\nof being compared with the data from our extensive meteorological\ninstrumentation consisting of high-speed humidity, temperature, and wind\nfluctuation sensors; one- and two-dimensional aerosol probes; and an array of\npath-averaging sensors that measure wind, rain, and refractive turbulence.\nPreliminary millimeter wave data indicate agreement with theoretical\npredictions based on the weak-scattering theory.\nThe recently completed Flatville data set contains the first combined\nmeasurements of infrared, millimeter, and visible wavelength scintillations.\nThese measurements will give us sensitivity to turbulent water vapor,\ntemperature, and wind speed fluctuations, and ultimately the ability to\nmeasure the path-averaged fluxes of these quantities.\nThe theoretical basis has been developed for a syntheticoaperture spatial\nfiltering device that will provide high-resolution vertical profiles of\nturbulence quantities (refractivity and microscale) from a single,\naircraft-mounted light source.\nA method was developed to compute errors for frequency estimators that\nuse spectral peaks; the technique has broad application to Doppler radars,\nlidars, and acoustic sounders.\nRESEARCH\nThe infrared Doppler radar was used to obtain real-time displays of\ndrainage flow in a straight, narrow, mountain valley. Wind flow contour\nanalysis was completed for three cases, including the transition from\nnightHtime down-valley to daytime up-valley conditions.\nWPL\nConvective plume fields were mapped using the Doppler lidar; spectral\nanalysis shows a mean plume size of 1 km.\nThe convergence triangle of WPL's optical crosswind sensors at its\nBoulder Atmospheric Observatory (BAO) was used in the MesoHGamma '85\nexperiment, and showed ground-level signatures characteristic of microbursts\nand strong updrafts.\nTurbulent velocities in the daytime boundary layer, measured by\n3-cm-wavelength Doppler radar using the velocity azimuth display (VAD)\ntechnique, were analyzed, and momentum flux profiles derived from variances of\nthe radial velocity.\n147","Cloud droplet size distributions in lenticular clouds were obtained by\ninverting the backscattered radiation, using three lidar wavelengths (from\nruby, doubled-ruby, and CO2 lasers) and the Backus-Gilbert technique.\nA study was completed for the Environmental Protection Agency, demonstra-\nting the accuracy to which the mean and turbulent structure of the convective\nboundary layer can be estimated by using simple and readily available measure-\nments.\nPlans FY 1986\nSENSOR DEVELOPMENT\nWPL will continue analysis of the Flatville data set to relate millimeter\nwave and optical scintillation data to simultaneous meteorological data. We\nwill perform a preliminary test of a path-averaged flux measurement technique\nusing these data. We will continue to refine our ability to make path=aver=\naged measurements of turbulent microscale, and hence momentum flux, on longer\natmospheric paths.\nIn connection with our high-resolution, vertical profiling of turbulence\nparameters using an aircraft-to-ground propagation path, we will conduct the\nfirst experimental tests of the concept on horizontal paths during FY 1986.\nThis work could have a significant impact on predicting outages of clear air\nradar echoes at different radar wavelengths.\nThe new Doppler minisodar will be tested using BAO data to determine limi-\ntations in accuracy and resolution. This sensor is designed for easy deploy-\nment in future field experiments, and is primarily intended for use in complex-\nterrain environments, and in wind-energy studies.\nPotential for use of the VAD technique for Doppler sodar measurements of\nstress will be explored through field experiments and intercomparisons with\nturbulence sensors on the BAO tower.\nA portable instrument package for measuring atmospheric conditions ber\nneath microbursts and in critical regions of downslope wind storms will be\ndeveloped to aid in the study of those events during Meso-Gamma '86.\nRESEARCH\nA major study of microbursts will be undertaken at the BAO during Meso-\nGamma '86, using the infrared Doppler lidar and microwave radars in addition\nto standard BAO instrumentation (meteorological tower, optical convergence\ntriangle, microbarograph array).\nAnalysis of Phoenix II (summer 1984) data will continue to determine mo-\nmentum flux in the boundary layer. Research into the use of temperature dif-\nferentials derived from wind fields in combination with radiometrically de-\nrived temperature profiles will continue.\n148","A field experiment will be conducted at BAO to compare the structure of\nCn2 in the lower atmosphere with simultaneous measurements of echo intensity\nprofiles from vertically pointing FM-CW radar and sodar. Findings from the\nexperiment are expected to improve our understanding of the effects of layered\nstructures on echo parameters measured by volume-averaging remote sensors.\nThe effect of inhomogeneous echo layers on Doppler wind estimation using vari-\nable pulse length sodars will be examined in tests at the BAO.\nStudies will be completed, summarizing gravity wave statistics collected\nduring FY 1984 and FY 1985.\nR&D ON MESO-BETA AND GAMMA SCALES\nA single ground-based scanning radar or lidar system can remotely monitor\natmospheric processes on the mesongamma (2 to 20 km) and perhaps the meso-beta\n(20 to 200 km) scales. Such data sets are required for an extraordinarily\nwide range of atmospheric research problems, as well as for short-term local\nweather nowcasts and forecasts. WPL progress in this area assigned to the\nWeather Observing and Prediction program is divided into two main categories,\nmesoscale sensor development and mesoscale research. Specific applications of\nWPL's mesoscale remote sensors to air pollution studies are discussed in the\nsection on Air Quality.\nAccomplishments FY 1985\nMESOSCALE SENSOR DEVELOPMENT\nA new CO2 laser, designed to provide a 100-fold increase in average radi-\nated power, was received from the manufacturer. After testing and modifica-\ntion in the laboratory, the new laser was installed in the Doppler lidar van,\nand the first atmospheric echoes were obtained using the most powerful coher-\nent infrared pulses ever used for atmospheric research.\nA 3=cm-wavelength Doppler radar was implemented with dual circular polar-\nization; this new feature will permit X-band depolarization measurements on\ndispersed chaff to provide a well-distinguished signature for study of entrain-\nWPL\nment.\nDesign of a 90-GHz radiometer to incorporate with an existing dual-\nchannel (20/30 GHz) radiometer was completed; this additional channel is ex-\npected to improve significantly the capability of remotely sensing both water\nvapor and liquid.\nRESEARCH ON MESO-BETA AND -GAMMA SCALES\nAn analysis of observations from the BAO tower, acoustic echosounder,\nPROFS mesonet, satellite imagery, and research aircraft was completed, demon-\n149","strating the formation of 1Hkm-scale hydraulic heads at surface fronts, and\ntheir relationship to the triggering of intense mesoconvective weather\nsystems.\nData taken during the NOAA-sponsored Arctic Cyclone Experiment (ACE,\n1984) were analyzed, and provided the first description of Arctic mesoscale\nfrontal structure and polar lows.\nThe Texas Dryline Frontal Zone Experiment was conducted during May 1985.\nDoppler lidar, dual-channel radiometer, rawinsonde, and research aircraft\nmeasurements were used to describe the structure and evolution of dry lines,\ncold fronts, boundary layer jets, upper-tropospheric jet streams, and boundary\nlayer turbulence. Of special note was the demonstration of the unique capabil-\nity of the Doppler lidar to measure the wind field of shallow fronts, and dry-\nline discontinuities prior to the onset of severe thunderstorm activity. The\ndualHehannel radiometer clearly measured water vapor discontinuities at the\ndryline.\nAnalyses of conventional rawinsonde soundings and total columnar ozone\ndata from an ozone-mapping polar-orbiting satellite (TOMS on Nimbus-7) showed\nthe relationship between the southward migration of a polar vortex and its\nassociated tropopause fold from northern Greenland to the Great Lakes, and the\nrecord-setting cold temperatures associated with the arctic outbreak of\nJanuary 1985.\nTwo highly successful long-term field programs in mountainous winter-\ncloud environments were performed at Steamboat Springs, Colo., and Beaver,\nUtah. A dual-channel radiometer and an 8.6-mm-wavelength dual-polarized Dopr\npler radar were used to observe supercooled liquid and ice particles in primar-\nily orographic cloud situations; several agencies (e.g., Desert Research Insti-\ntute, Colorado State University, University of Utah, Environmental Sciences\nGroup of ERL) are also analyzing the data.\nData obtained using the NAVSTAR satellites and two receivers of the\nGlobal Positioning System located on a 22-km baseline near Boulder, Colo.,\nshowed that steerable dual-channel radiometers, located at the baseline termi-\nnals, provided corrections for apparent path length changes introduced by vari-\nations in tropospheric water vapor. The corrections improved the rms preci-\nsion of the 22-km baseline measurements from 4.7 cm to 1.3 cm.\nVariability of pressure heights and layer thicknesses were measured by\nthe six-channel Profiler radiometer at the Denver WSFO; the time series and\nspectra of these pressure heights and thickness variations correlate well with\nindependent measurement of gravity waves.\nA statistical study of the ability to predict icing of aircraft used\npilot reports for an area surrounding Denver, Colo. Analysis of independent\npredictors such as surface temperature or cloud cover showed that cloud liquid\nwater, measured by dual-channel radiometry, has by far the strongest correla-\ntion with icing, especially during winter months.\nA Front Range boundary layer mesoscale model was developed, capable of\nsimulating two basic features of the flow in the Denver area: the \"Denver\ncyclone\" for southerly winds and the \"Longmont anticyclone\" for northerly\n150","winds. The Palmer ridge south of Denver was shown to be the main\ntopographical feature, aside from the Front Range, responsible for the\nformation of the Denver cyclone. The Cheyenne ridge plays a similar role in\nthe formation of the anticyclone. The associated convergence lines, which are\npreferred regions for thunderstorm development, are also predicted by the\nmodel.\nA mesongammariscale experiment (Meso-Gamma '85) was conducted at the BAO\nduring June and July of 1985 to study events on that scale occurring along the\nColorado Front Range. Of particular interest were terrain-induced\nmesocyclones and anticyclones and associated convergence lines. Data\ncollected with the BAO sensors, aircraft, rawinsondes, FM-CW radar, profilers,\nand the PROFS Mesonet, documented several mesocyclones that spawned severe\nweather (rain, hail, lightning, high winds, and tornadoes). These data will\nbe used to evaluate the performance of WPL's Front Range boundary layer\nmesoscale model. In addition, eight microbursts and two gust front passages\nwere carefully monitored at the 300-m BAO meteorological tower. The\nmicroburst and gust data are providing unique and essential information for\nthe design of wind shear prediction and detection systems to be used at\nairports.\nSimultaneous measurements at the BAO and along the Rocky Mountains have\nrevealed a double-structured boundary layer at the BAO. The double structure\nresults from an upper-level mountain boundary layer advecting over and capping\nthe underlying plains boundary layer. This observation, made during the\nMesoGamma '85 experiment, has important implications for studies of the\ndaytime boundary layer along the Front Range.\nAll wave events occurring during one month in the spring and one in the\nwinter were documented to develop a climatology of gravity/shear waves in the\nFront Range region. Studies are under way, in collaboration with Georgia\nInstitute of Technology, to examine the pressureovelocity correlations in such\nevents.\nPreliminary modeling of flow in the Santa Barbara, Calif., area was\ncompleted for the South Central Coast Cooperative Aerometric Monitoring\nProgram (SCCCMP) experiment. The model shows strong topographical channeling\nof the flow by offshore islands and coastal mountains. These model results\ncompare favorably with the limited wind observations now available.\nAnalyses of the Doppler lidar data from the Brush Creek experiment\nWPL\ndemonstrated the ability of the lidar to measure volume flux divergence\naccurately over 300-m intervals within a channeled nocturnal drainage flow.\nDoppler minisodar flux estimates confirmed lidar-measured volume flux\ndivergences arising from tributary flows.\nAn experiment to measure aircraft response to orographically perturbed\nflows along the Colorado Front Range was completed. The aircraft response\ndata will be compared with ground-based in situ and remote sensor data. This\nexperiment was conducted in support of the FAA aircraft vertical separation\nprogram.\n151","Plans FY 1986\nMESOSCALE SENSOR DEVELOPMENT\nThe new Doppler lidar will be tested alongside the BAO meteorological\ntower to determine the accuracy of its wind measurements. New data systems,\nincluding computers and color displays, will be installed on the 8.6FmmH and\n3-cm-wavelength pulse-Doppler radars.\nThe three dual-channel humidity Profilers of the Colorado Plains Triangle\nNetwork will be calibrated by individual side#by*side tests with the mobile\ndual-channel instrument, which will serve as a reference standard.\nWPL's radar wind Profilers were designed primarily for use at the synop-\ntic and meso-alpha scales. A study will be made to determine if the 405-MHz\nProfiler can be modified to produce wind profiles with better temporal resolu-\ntion (N5 min) and 150-m height resolution to a maximum height of 6-8 km MSL\nfor meso-betaHscale applications.\nRESEARCH ON MESO-BETA AND -GAMMA SCALES\nChinook wind profiles will be measured with the Doppler lidar in observa-\ntions coordinated with the PROFS winter exercise.\nThe analysis of dryline fronts observed at Midland, Tex., will be com-\npleted.\nAnalysis of data from observations taken at Beaver, Utah, and Steamboat\nSprings, Colo., will continue, to obtain an improved understanding of winter\norographic clouds, with emphasis on the behavior of supercooled liquid.\nObservations of summer clouds, using several remote sensors such as\nradars, radiometers, and lidar (Project Echoes), will be taken using the BAO\nas the central site.\nAnalysis will start on data collected during Meso-Gamma '85. Various\naspects of mesoscale cyclones, anticyclones, convergence lines, microbursts,\nand gust fronts will be studied.\nImprovements in the mesoscale model developed for the Santa Barbara area\nwill be made on the basis of wind observations obtained from the SCCCMP experj-\nment.\nA second meso-gamma-scale field experiment, designated Meso-Gamma '86, is\nplanned for the summer of 1986. In addition to the sensors used in the 1985\nexperiment, it will deploy Doppler radars and Doppler lidar to explore the\nthree-dimensional structure of convergence lines and microbursts. The primary\nobjective of the experiment is to explore and demonstrate the potential of\nWPL's complement of remote sensors for studying atmospheric motions on the\nmesoHgamma scale.\n152","In a separate experiment following Meso-Gamma '86 the structure of drain-\nage winds at the BAO will be observed using Doppler lidar, sodars, and the\ntower instrumentation.\nR&D ON SYNOPTIC AND MESO-ALPHA SCALES\nAlthough individual ground-based remote sensors are limited by Earth cur-\nvature to meso-beta scale applications, arrays of such sensors can be used to\nstudy atmospheric processes up to continental scale. WPL's planned contribu-\ntion to this scale is the Profiler, a combined radar-radiometer system for the\ncontinuous measurement of profiles of wind, temperature, and humidity. A suit-\nable array of such systems could continuously provide the threerdimensional\nfields of these parameters on the meso-alpha (200 to 2,000 km) and synoptic\n(2,000 to 10,000 km) scales for numerical weather prediction (NWP). Such a\nsystem would have major impact on NWP since the observation data could be (1)\ntime-averaged to remove aliasing of high-frequency components, (2) entered\nmore frequently into the NWP algorithms, and (3) inserted in the form of time\nderivatives as well as time averages. It is also believed that the wind field\ndata (which are critical to mesoscale NWP) would be considerably more accurate\nand representative than those available from radiosondes.\nAccomplishments FY 1985\nA 405-MHz radar wind Profiler was completed and tested. It was installed\nat Platteville, Colo., to avoid interfering with radiosonde research by NCAR\nin Boulder. Data are available in the Profiler data base starting with\nJanuary 1985. The radar operated with pulse widths of 1, 3, and 9 us and two\nantenna pointing directions during 1985. Outage times, due to lack of suffi-\ncient echo strength, have been computed for each height, pulse length, and\nmonth.\nThe Colorado Profiler Network was restructured to provide wind profiles,\ntotal water vapor, and liquid water along a zenith path, and surface data at\nfour stations on the high plains of eastern Colorado (Fleming, Flagler,\nPlatteville, and Stapleton Airport). This network supplied real-time data for\nPRE-STORM (Preliminary Regional Experiment for Stormscale Operational and Re-\nsearch Meteorology) and for PROFS. It continued to supply data for use by\nWPL\noperational and research meteorologists at NWS and the FAA. Improvements were\nmade to protect the radars from lightning and to allow remote restart after\nlong-term power outage.\nThe Colorado wind Profiler network was shown to provide temporally and\nvertically consistent vorticity and divergence profiles. The procedure was\nadopted by PROFS for real-time application during the PROFS Warm Season Experi-\nment.\nA statistical evaluation of the 50-, 405-, and 915-MHz radar wind Pro-\nfilers was performed to characterize the height coverage and data outage of\nvarious-wavelength wind Profilers. Height coverage for a given radar depends\non the characteristics of the particular air mass that is overhead; longer\n153","wavelength radars generally perform better at upper tropospheric and lower\nstratospheric altitudes than shorter wavelength radars with comparable sensi-\ntivity.\nWPL wind Profiler technology was transferred to NSSL/Oklahoma University\nwith the installation of a VHF radar near Norman, Okla. This radar was con-\nstructed using spare parts from the Colorado network.\nWPL assisted Penn State University (PSU) in setting up its first VHF wind\nProfiler radar near College Station, Penn. The PSU radar uses the WPL-\ndesigned radar controller/data preprocessor and WPL's data processing and soft-\nware.\nThe WPL Profiler Technology Transfer Group (PTTG) was formed to design\nand implement a network of wind Profilers across much of the midwestern United\nStates. The network will include 30 wind Profilers (both 50-MHz and 405-MHz\nversions) and a Hub for data collection and distribution.\nDocuments essential for Profiler network planning and procurement were\nwritten: (1) the network's functional requirements, (2) the Hub design, and (3)\ndefinition of the work to be done by the contractor selected to build,\ninstall, and maintain the network of Profilers. The National Data Buoy Center\nwas chosen to handle the procurement. In March, a technical symposium on the\nstructure and uses of Profilers was held in Boulder; representatives from 24\ninterested companies attended. The standard data exchange format of the\nOffice of the Federal Coordinator for Meteorological Services and Supporting\nResearch was adopted for network data transmission; PTTG suggested some addi-\ntions to that format for Profiler data and these were accepted. Working\nclosely with the National Weather Service, PTTG began writing a plan for the\nassessment of the network in general and wind Profilers in particular as poten-\ntial operational tools. Work began on a WPL 405-MHz Profiler prototype that\nwill be integrated into a minitnetwork to begin operating in FY 1986. In\nAugust the network radar procurement plan was approved by the NOAA Administra-\ntor, and requests for proposals to build the 405-MHz wind Profilers were sent\nout to industry by the National Data Buoy Center.\nPlans FY 1986\nResearch will be conducted on the theory and application of the colinear-\ncoaxial antenna for UHF and VHF wind Profilers. This type of antenna is used\nat VHF and could perhaps provide a lower cost UHF antenna than the Yagi\nantenna array that is now used.\nThe performance of various-wavelength wind Profilers at upper tropo-\nspheric and lower stratospheric altitudes will be compared with meteorological\nconditions to determine whether the height coverage of wind Profilers can be\npredicted from conventional meteorological parameters.\nWind measurements from a wind Profiler with five antenna-pointing posi-\ntions will be studied to determine whether radar wind measurements using two\nand three beam-pointing directions have systematic differences that depend on\n154","the beam positions used. Comparisons will be made to investigate differences\nbetween hourly-averaged winds and winds measured every 5 minutes.\nResearch will be conducted on improving the data processing algorithms\nused to operate wind Profilers. The data archived for analysis will be ex-\npanded so that different processing techniques can be tested.\nCase studies, based on observations made with the Colorado High Plains\nnetwork of wind Profilers, will be conducted.\nNumerical simulation of wind and radiometric temperaturemprofiling net-\nworks will be conducted to provide guidance for the design of future regional\nand national upper-air observing networks. This is a cooperative effort of\nWPL, CIRES, and NCAR.\nThe study of Arctic synoptic and mesoscale weather systems will continue,\nusing NOAA-7 and -8 satellites, and NOAA P-3 aircraft observations.\nWPL scientists will also participate in the Arctic Gas and Aerosol Sampl-\ning Program (AGASP II, 1986), and in the Genesis of Atlantic Lows Experiment\n(GALE).\nThe assessment plan for the 30-station network of wind Profilers will be\ncompleted.\nA mini-network of already existing wind Profilers in Colorado will con-\ntinue operation, sending data into the Hub in Boulder. The data will be sent\nfrom the Hub to assessment teams, to local research scientists, and to PROFS.\nA link to AFOS (Automation of Field Operations and Services) will be com-\npleted, and data from the wind Profiler mini-network will go out on that NWS\nsystem.\nThe WPL 405-MHz wind Profiler will be completed and integrated with the\nmini-network.\nA contract will be awarded for the commercially built 405-MHz wind Pro-\nfilers.\nRequirements and other significant documents for procurement of 50-MHz\nwind Profilers will be completed; requests for proposals will be sent out by\nWPL\nthe National Data Buoy Center.\nSite for the 30 wind Profilers will be selected. Staff from the Central\nRegion of NWS will begin the process of leasing and preparing the sites.\nA wind Profiler site communication system will be designed that uses both\nsatellites and telephone lines.\n155","AIR QUALITY\nNOAA's weather service mission includes the provision of meteorological\ninformation and understanding relevant to air quality. WPL contributes to\nthis program through the application of its remote sensors to the measurement\nof the three-dimensional fields of wind, turbulence, and aerosol in experie\nments relating to air pollution.\nAccomplishments FY 1985\nA network of 13 WPL-developed optical crosswind sensors was used in the\nASCOT '84 field experiment in western Colorado. These sensors quantitatively\nassessed the contributions of tributary canyon and canyon sidewall slope flow\nto canyon air drainage, and have shown the diurnal pattern of mountain-valley\nwinds.\nSoftware was developed for real-time processing of stratospheric turbid-\nity profiles measured using the ruby lidar. Stratospheric lidar echo intens-\nity profiles were measured weekly, throughout the year.\nThe processing of lidar plume data taken during the EPA Hogback Ridge and\nTracy Power Plant field experiments was essentially completed. Lidar observa-\ntions of meandering plumes during the BAO Convective Dispersion Observed by\nRemote Sensor (CONDORS) experiment were processed, and passed to ARL for use\nin air pollution model testing. Analysis of data collected during the 1984\nEPA Tracy Experiment in Nevada demonstrated the ability of sodars to measure\nthe vertical extent of mixing layers, with confirmation from simultaneous\nlidar plume mappings.\nThe field phase of the DOE ASCOT Brush Creek drainage experiment was bril-\nliantly successful, primarily because of the presence of the infrared Doppler\nlidar; analysis of the data continues.\nPapers on ASCOT experiments conducted between 1979 and 1982 documented\nthe use of acoustic remote sensors in complex terrain studies, and the impor-\ntance of (1) internal waves to the production of intermittent katabatic flows,\n(2) inertial rotation of sea breeze to valley circulation, (3) sideHwall heat-\ning to inversion descents in basins, and (4) interfacial mixing to transport\nand diffusion problems.\nPlans FY 1986\nAnalysis of drainage flow in a narrow mountain valley will be completed,\nusing multi-sensor data from the 1984 Brush Creek experiment.\nThe multi-year EPA-supported studies of transport and diffusion in com-\nplex terrain will be completed with summaries of the results of the program.\n156","CLIMATE\nAccomplishments FY 1985\nWPL simulated the propagation of acoustic waves across the Florida\nStraits for the SubTropical Atlantic Climate Studies (STACS) program. Results\nshowed that in modeling the performance of acoustic sensors of heat flux in\nthat area, which covers most of the northward heat flux in the North Atlantic,\ncontinuous models of the geometry of the bottom reflections are crucial.\nMARINE OBSERVATION AND PREDICTION\nAccomplishments FY 1985\nWPL completed the documentation of its threerdimensional, Hamilton-based,\nray tracing program for the ocean. The program, called HARPO, is available\nfor propagation modeling, which is essential in the analysis and interpreta-\ntion of tomographic experiments.\nWPL developed an objective method for inverting vertical-slice tomography\ndata and extended the method to asymmetrical sound-speed profiles and transmit-\nters and receivers off the sound-channel axis. This new result will enhance\nthe value of existing and future tomographic data sets.\nWPL demonstrated experimentally the feasibility of measuring path-\naveraged transverse currents in turbulent channels, using observations of both\nphase and amplitude scintillations as flow estimators. A patent was applied\nfor.\nPlans FY 1986\nWPL will deliver to the Scripps Institution of Oceanography's tomography\ngroup a documented version of the 3rd propagation code HARPO for use with the\ngroup's objective mapping methods for tomography modeling. WPL and Scripps\nWPL\nwill jointly perform research to reconcile discrepancies between measured\nsound speed fields and measured pulse arrival sequences in past tomography\nexperiments, and set up propagation models with real 3rd data fields to model\nplanned tomography experiments.\nWPL will investigate the possibility of obtaining ocean wave-directional\nspectra using a bottom-mounted, acoustic, CODAR-analog device.\nWPL will extend the theoretical basis of the scintillation technique to\ninclude measurement of currents and internal wave spectra in the presence of\nan internal wave field and on long acoustic paths in the deep ocean.\n157","","Lester Machta\nAIR RESOURCES LABORATORY\nDirector\nSilver Spring, Maryland\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nSEL\nWPL\nARL\nAL\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nThe Air Resources Laboratory (ARL) includes a headquarters group in\nSilver Spring, Md. ; the Field Research Division in Idaho Falls, Idaho; the\nAtmospheric Turbulence and Diffusion Division (ATDD) in Oak Ridge, Tenn.; the\nMeteorology Division in Research Triangle Park, N.C.; the Sun-Climate Staff,\nthe Air Quality Division, and the Geophysical Monitoring for Climatic Change\nDivision (GMCC) in Boulder, Colo; and GMCC observatories at Mauna Loa\n(Hawaii), Barrow (Alaska), the South Pole, and American Samoa.\nARL research is geared to needs of users, who are frequently other\nFederal agencies with related missions. Funding and guidance derive from this\nassociation through interagency agreements. In some cases, the ARL unit under\ncontract to another agency acts as its meteorological arm to provide meteoro-\nlogical guidance. Most ARL research deals with the use of meteorology to\nunderstand and predict human influence on the environment, especially with\nregard to the atmospheric transport and diffusion of toxic effluents. General\nareas of study include turbulence and diffusion in the atmosphere, atmospheric\ntrajectories from microscales to global scales, meteorology of air pollution,\nCO2 and climate, acid rain, and monitoring of atmospheric constituents for\nARL\nclimatic change. Following general descriptions of the work of the ARL\ngroups, ARL research activities are described here under two main headings,\nAir Quality and Climate. Many of these activities involve cooperation among\nthe Divisions.\nHEADQUARTERS GROUP\nThe research group in Silver Spring develops models that simulate local,\nregional, and global transport and diffusion of pollutants injected into the\natmosphere. Mesoscale and regional-scale versions of these models are being\nused extensively to evaluate the environmental effects of various types of\nenergy production. Air-sampling programs and other field experiments are con-\n159","ducted to provide data for model verification. Major funding for this work is\nprovided by the Department of Energy (DOE) Office of Health and Environmental\nResearch. Research on total-ozone and ozone-profile data and on the sources,\ntransport, and deposition of acid precipitation is also being carried out.\nClimate studies include research on the sources and sinks of CO2 in the atmos-\nphere, on global temperature and humidity changes, and on sunshine duration\nand cloudiness over the contiguous United States.\nFIELD RESEARCH DIVISION\nMost of the research of ARL's Field Research Division in Idaho is spon-\nsored by the Nuclear Regulatory Commission (NRC), DOE, and the Environmental\nProtection Agency (EPA). It is directed toward current and anticipated envi-\nronmental problems associated with the release to the atmosphere of toxic and\nundesirable effluents by our industrialized society. These problems include\nthe quantification of downwind atmospheric dispersion contributed by the\nmeander of plumes under light wind and inversion conditions, the effect of the\nland-sea interface, the effect of surface roughness and complex mountainous\nterrain, the measurement of the vertical as well as the horizontal profile of\nplume concentration, and the measurement of air trajectories. Tracer gas tech-\nniques and radar-tracked, constant-level balloon trajectories as well as stand-\nard meteorological profiles of wind and temperature are used in full-scale\nfield experiments to address these problems and provide the necessary data to\nverify transport and diffusion models\nATMOSPHERIC TURBULENCE AND DIFFUSION DIVISION\nThe Atmospheric Turbulence and Diffusion Division in Oak Ridge, Tenn., is\ngenerally concerned with air quality. ATDD conducts research on the physics\nof the lower atmosphere, with emphasis on the processes contributing to atmos-\npheric transport, dispersion, and deposition, and on the development of models\nusing the results of this research. Research is directed toward practical\nissues important to both NOAA and DOE's Oak Ridge Operations Office; the\nlargest single source of support is the DOE Pollutant Characterization and\nSafety Research Division. Additional sources of support include NOAA, EPA,\nthe Department of Defense (DOD), and NRC. The research program is divided\ninto four main areas: plume transport and diffusion in the planetary boundary\nlayer, complex topography, atmosphere-canopy interactions, and dry deposition.\nA fifth component makes use of wind-tunnel modeling to address questions of\nnear-field dispersion and deposition arising in the four main areas of re-\nsearch. Studies are conducted in close collaboration with Oak Ridge National\nLaboratory and with atmospheric science units at other national laboratories,\nuniversities, and Federal agencies.\nMETEOROLOGY DIVISION\nMeteorology Division support and services to EPA include theoretical and\nexperimental studies of the physical processes affecting transport, diffusion,\ntransformation, and deposition of air pollutants; development, evaluation,\nmodification, and dissemination of air quality simulation models for inert and\nreactive pollutants; effects of air pollutants on weather and climate; and\n160","studies to define the relationships between air quality and meteorological\nquantities.\nThe Meteorology Division also provides operational support to various EPA\ngroups. This includes technical advice; applications of air quality simula-\ntion models; evaluation of the meteorological portions of state implementation\nplans, environmental impact statements, and requests for variances; expert\ntestimony at public hearings and judicial proceedings; emergency field serv-\nices; preparation of technical staff reports and documents.\nSUN-CLIMATE STAFF\nThe Sun-Climate Staff conducts fundamental research on the cause and\nmechanisms of climatic change, on time scales of months to decades, including\nsolar variability as a possible cause. The application is directed toward,\nbut not limited to, climatic change in the United States. The approach is to\ndevelop understanding of climatic processes through analytical studies using\nclimatic, oceanographic, solar radiation, ozone, and other data, principally\nthose representative of the current century. Research on the temporal varia-\ntions of solar ultraviolet (UV) radiation, their stratospheric effects, and\npossible coupling to the troposphere and climate is conducted using measure-\nments from the SBUV/2 instruments aboard NOAA satellites and other sources,\nand using theoretical models of the stratosphere and stratosphere-troposphere\ncoupling.\nA ground-based system to measure the secular characteristics of solar\nspectral changes in UV, visible, and near infrared wavelengths has been under\ndevelopment since 1980. The effects of atmospheric attenuation on these\nsurface-based measurements are also being studied.\nAIR QUALITY DIVISION\nAir Quality Division research is directed, within the mesoscale in the\nlower troposphere, to (1) improving the understanding of the mechanisms of\nformation, residence times, and sinks of natural and anthropogenic cloud and\nice nuclei; (2) elucidating the effects of those nuclei, other aerosols, and\ntrace gases on the formation, colloidal stability, optical properties, and\nchemical composition of clouds; (3) determining the effects of pollutants on\nthe radiation budget, visibility, and atmospheric electrical phenomena. In\n1986 this work will be done in the GMCC Division.\nARL\nGEOPHYSICAL MONITORING FOR CLIMATIC CHANGE DIVISION\nThe mission of the GMCC Division is to measure, over a long period of\ntime, atmospheric greenhouse gases and the long-range transport of aerosols in\nthe atmosphere. The measurements, at NOAA's four GMCC baseline observatories\nand other locations, are used to determine whether these gases and aerosols\nare changing with time and to identify natural and anthropogenic sources and\nsinks as well as temporal and hemispheric gradients and global budgets. Green-\nhouse gases and aerosols interact with solar and terrestrial radiation and\nthus trends and gradients of these substances can alter the Earth's climate.\n161","AIR QUALITY\nATMOSPHERIC TRANSPORT\nAccomplishments FY 1985\nData obtained in the Cross-Appalachian Tracer Experiment (CAPTEX) have\nbeen made available on magnetic tapes for the use of air pollution modelers\nand other atmospheric scientists. CAPTEX was a .S.-Canadianeffort led by\nARL, to study long-range transport and dispersion. A perfluorocarbon tracer\ngas was released at Dayton, Ohio, and Sudbury, Ontario, and concentrations\nwere measured in thousands of air samples collected at 80 sites in the United\nStates and Canada, some as far as 1100 km from the source. CAPTEX data are\nbeing used by ARL and other researchers to test and improve the transport and\ndispersion modules of air pollution and acid deposition models.\nDuring January-April 1985, the Air Quality Division participated in the\nWestern Atlantic Ocean Experiment (WATOX). The objective of the project was\nto estimate the eastward flux of air pollutants emitted in the United States.\nIn addition to the ARL aerosol- and gas-analyzing equipment carried aboard the\nKing Air C-90 aircraft, instruments were provided by scientists from several\nuniversities and research institutions. Gaseous pollutants analyzed were SO 2\nNO, NO, 03, dimethyl sulfide (DMS) and C1-C4 hydrocarbons. Measured aerosol\nvariables included SO NO 3 , trace metallic elements, and size distribu-\n-\ntions. In addition, meteorological quantities and flight data were recorded.\nFlights were conducted over the Atlantic Ocean approximately 100 km east\nof Newport News, Va., during February and March 1985, and in the vicinity of\nthe Bermuda Islands during April 1985. The measurements indicated that the\nflux of SO eastward across the coastline between 33° and 38°N was on the\norder of 1 Tg (S) yr This value is consistent with previous estimates\nbased on climatological data. DMS was detected only within the planetary\nboundary layer; the observed concentrations were 278 ppt near the U.S. coast\nand 5620 ppt in the vicinity of Bermuda. The DMS concentrations decreased\nsignificantly as altitude increased, but there was no observable diurnal\nvariation.\nAtmospheric measurements of natural sulfur compounds were performed over\nthe northern Gulf of Mexico during the late summer months of 1984. Air and\naerosol samples were collected with an instrumented aircraft at elevations of\n30-3500 m, during both day and night. Most air samples were representative of\nthe clean maritime atmosphere, although some were from continental contamina-\nted air during periods of offshore flow at the coastline. In all samples\ncarbonyl sulfide concentrations were within the range of 400-500 pptv, but DMS\nconcentrations showed significant variability. During \"clean\" atmospheric\nconditions the mean concentration was 2730 pptv, whereas under polluted condi-\ntions it was 73 pptv. In all cases where DMS concentrations were measured at\nmore than one altitude during the same flight at the same location, a strong\nvertical gradient was detected within the boundary layer. Dimethyl sulfide\n162","was not detected above the boundary layer. This suggests that atmospheric DMS\nconcentrations are surface derived, have a lifetime commensurate with the\nboundary layer mixing time, and are very sensitive to the presence of trace\natmospheric pollutants. Aerosol sulfate concentrations in the clean marine\natmosphere boundary layer, together with the DMS data, in a simple model indi-\ncated that upper and lower limit estimates of the sulfur flux northward from\nthe Gulf of Mexico are 0.25 and 0.04 Tg (S) yr During March and April\n1985, air samples were also collected over the Atlantic Ocean approximately\n100 km offshore from the Delmarva coast and in the vicinity of Bermuda. As in\nthe Gulf samples, a strong gradient was evident within the boundary layer.\nA computer model for the marine atmospheric chemistry under both clean\nand polluted conditions was developed and validated using WATOX data from both\nsampling sites. The model calculations indicate that the trace gaseous con-\ntent of the air masses sampled in Bermuda can be predicted on the basis of the\nanalysis of samples collected near the East Coast, thus supporting the assump-\ntion of direct, long-distance transport of air pollutants over the ocean.\nAerosol size distribution data from the 1983 Whiteface Mountain experi-\nment were re-examined to evaluate the aerosol-scavenging process during cloud\nformation, and the release of aerosols upon cloud evaporation. Clouds ob-\nserved at the summit were found to have absorbed particulate matter predomi-\nnantly through nucleation scavenging. Approximately 10% of the initial\naerosol population was not activated as condensation nuclei, and remained in\nthe cloud interstitial space. Following evaporation of the cloud, the result-\ning particle concentration was double the pre-cloud concentration, and the\naerosol mass was greater by a factor of 4 or 5. This was interpreted to mean\nthat new aerosol mass was being created by oxidation of the sulfur and nitro-\ngen oxides to sulfate and nitrate within the cloud drops.\nThe King Air research aircraft was used in a study near Oklahoma City,\nOkla., during June 1985. This study, the Processing of Emissions by Clouds\nand Precipitation (PRECP) was conducted cooperatively with Battelle Pacific\nNorthwest Laboratories, the University of Maryland, and the University of\nDenver, and had as its goals (1) explicating mechanisms by which acid precur-\nsor gases and aerosols are processed by convective cloud systems, (2) determin-\ning the extent to which boundary layer aerosols were vented to the free tropo-\nsphere, and (3) determining whether new aerosols were being created. Prelimi-\nnary analyses suggest that nitrates and sulfates in boundary layer concentra-\ntions were being transported to altitudes as high as 10 km.\nA field research project in the Grand Canyon was carried out by the Air\nARL\nQuality Division in cooperation with the National Park Service and the Coopera-\ntive Institute for Research in the Atmosphere. During two field periods in\nautumn 1984 and three in spring, an instrumented Cessna T207 research aircraft\nand ground observations were used to measure vertical and horizontal wind pro-\nfiles in the canyon and to measure radiation from the canyon floor and walls.\nThe purpose was to describe the dynamics of air flow in the canyon, and thus\nto enable Park Service personnel to burn understory vegetation without impair-\ning visibility in this Class I area. Preliminary evaluation of the accumu-\nlated data indicates that thermal radiation is the driving force for air ex-\nchange between the Grand Canyon and the free troposphere.\n163","During July 1985, cloud and aerosol composition-versus-altitude measure-\nments were conducted with the King Air in the vicinity of Whiteface Mountain,\nN.Y. Cloud water samples collected at four levels in a deep stratus deck in-\ndicated a greater loading of dissolved substances per unit volume of atmos-\nphere in the lower part of the cloud layer, but the pH and loading of dis-\nsolved substances per unit mass of cloud water were fairly uniform through the\ncloud.\nPlans FY 1986\nA CAPTEX model evaluation workshop will be held in November 1985. It\nwill provide an opportunity for researchers to present and evaluate model\nresults, suggest means of improving model performance, and discuss the lessons\nto be learned from CAPTEX for planning future large-scale atmospheric trans-\nport and dispersion experiments.\nThe importance of using more frequent meteorological data in long-range\ntransport calculations will be evaluated by comparing output of an NWS bound-\nary layer forecast model with 6-hourly rawinsonde observations taken during\nCAPTEX.\nThe second, third, and fourth phases of the WATOX project are scheduled\nfor FY 1986. The second phase will include a series of King Air air-sampling\nflights 100 km offshore in the vicinity of Boston, Mass., during January-March\n1986. Research flights in January will be performed concurrently with a NOAA\nP-3 aircraft. The King Air will be used for vertical profiles of gas and\naerosol parameters, and the P-3 will conduct measurements over long distances\nat constant altitude. The detailed vertical and horizontal profiles obtained\nwill provide a high quality data base for flux estimations. During February\nand March the King Air will measure horizontal and vertical profiles during\nperiods of offshore airflow. The fourth phase, scheduled for May 1986, will\ninclude a similar series of horizontal and vertical profiles measured in the\nvicinity of Bermuda during episodes of airflow from all four geographical quad-\nrants. In addition to the WATOX objectives, measurements of naturally derived\nsulfur-containing substances will continue, to evaluate further their contribu-\ntion to precipitation acidification.\nPlans are being formulated for a possible continuation of the PRECP\neffort in northeast Colorado during summer 1986, in cooperation with Battelle\nPacific Northwest Laboratories and NASA.\nThe Grand Canyon project will be terminated in March 1986.\nTwo alternatives are being considered for a field study to estimate the\nrate of oxidation of sulfur dioxide to sulfate in clouds. These are the\nmeasurement of sulfur dioxide, sulfurous acid, and sulfate in clouds at\nvarious distances downwind (1) from a point SO2 source such as a coal+fired\npowerplant where the smoke plume discharges into a stratus cloud, or (2) from\nthe release of sulfur dioxide into a cloud from a helicopter, along with SF\nas a plume tracer. The analyses would be on cloud water and air within the\ncloud as sampled with the King Air.\n164","ATMOSPHERIC TRACERS\nAccomplishments FY 1985\nThe Field Research Division participated in a flight test program of the\nhelicopter vortex wake/downwash flowfield; it supplied the meteorological pro-\nfile instrumentation and turbulence instrumentation in support of the tests.\nThe first phase of the tests was run during July 1985, for the T-34B/Vortex\nwake probing. The measurement techniques were similar to those used in the\nFederal Aviation Administration (FAA) superjet wake vortices study. FAA spon-\nsored this research as part of its S-76 helicopter test program.\nA preliminary study was conducted at Whiteface Mountain in upper New York\nState to measure the oxidation rate of SO2 in clouds by introducing SO2 concen-\ntrations into clouds. SF6 was also introduced to identify the appropriate air\nmass. This research was carried out in cooperation with the Atmospheric\nScience Research Center of the State University of New York at Albany.\nExtensive measurements of low-altitude winds, temperatures, and balloon\ntrajectories were performed during the DOE tests for transient fuel damage at\nthe Power Burst Facility and Loss-of-Fluid Test nuclear reactors. Post-test\nmodel calculations of trajectories, diffusion, and exposure from postulated\nairborne radionuclides were prepared and critiqued with DOE scientists.\nNuclear powerplants are required to have Atmospheric Transport and Diffu-\nsion (ATD) models capable of making dose assessments in the event of an emer-\ngency. Under an NRC contract, the Field Research Division developed methods\nof evaluating ATD models. Data cases have been assembled that test a model's\nperformance under a variety of situations. Reference models were selected to\ncompare model results from these test data sets. Evaluations were performed\non ATD models used at two operating nuclear powerplants.\nEPA-sponsored developmental research continued on an advanced operational\nsystem for tracking multiple Lagrangian markers (tetroons) on a regional scale.\nAn experimental prototype has been developed of a miniaturized tetroon trans-\nmitting and receiving system employing Loran-C and Omega systems and capable\nof providing continuous real-time data on longitude/latitude, ambient pressure\n(altitude), and temperature. Field testing was accomplished during FY 1985 tn\nranges of 1000 miles.\nARL\nGaseous tracer and sampling support was provided during the South Central\nCoast Cooperative Aerometric Monitoring Program field study covering the area\nfrom the Los Angeles Basin to Santa Barbara.\nThermal, remotely sensed data were analyzed to show how urban land areas\nwithin the Salt Lake City area interact with the lower atmosphere to determine\nthe urban climate of the area. Field Research Division meteorological instru-\nments provided ground level meteorological conditions and solar radiation\ndata, and analyzed the data. NASA sponsored this research project.\n165","The Field Research Division contributed to and supported a test by the\nUniversity of Michigan, Department of Environmental and Industrial Health\nCyclotron/Positron Emission Tomography Facility, by measuring dispersion of\nemissions from a cyclotron vault and laboratory hot cell and hoods by releas-\ning tracers and having air samplers positioned around the facility. Analysis\nwill be done in conjunction with the University of Michigan.\nGas chromatography laboratory hardware and software were modified to per-\nmit processing of more than 2000 tracer samples per day, along with calibra-\ntions and quality assurance checks. Initial tracer analyses were performed\nand supplied to EPA within 48 h of data collection. Feedback of results\nallowed in-the-field review and modifications of field measurement programs.\nThis project was sponsored by EPA.\nPlans FY 1986\nA report to NRC will describe the methods and data cases used to evaluate\natmospheric transport and diffusion models. Reference models will be com-\npared. Nuclear powerplant atmospheric transport and diffusion models will be\nevaluated upon request. by the NRC.\nThe South Central Coast Cooperative Aerometric Monitoring Program will\ncontinue with a minimum of five tests.\nA prototype gas chromatograph will be developed and tested as part of the\nautomated gas chromatography laboratory. This prototype will analyze the\nnext-generation types of gaseous tracers suitable for regional and larger\nscale studies.\nARL will carry out, in cooperation with the U.S. Army, a project on the\ndispersion of military smoke over rolling terrain and flat terrain. It will\nconsist of meteorological instruments and sample and tracer releases.\nContinued long-range tracking and a new digital design transponder will\nbe tested during FY 1986.\nThe FAA helicopter study will continue through FY 1986.\nPrototype samplers will be adapted from existing units for extended-\nperiod sampling of next-generation gaseous tracers. Alternate designs will be\nassessed.\nPLUME DISPERSION\nAccomplishments FY 1985\nARL's year-long Metropolitan Tracer Experiment (METREX) in the\nWashington, D.C., area was completed in January 1985. The experiment was\ndesigned to provide data to evaluate dispersion models in an urban setting and\nto develop and compare dispersion climatologies over adjacent urban and rural\nareas. Perfluorocarbon tracers were released at two sites every 36 hours.\n166","Average monthly tracer concentrations were measured at about 90 sites, and\ncontinuous 8-h samples were collected at three sites.\nA model to simulate the airflow over an urban heat island was developed.\nVarious simulations showed that the low-level heating of the rural air as\nit\npassed over the city enhanced the vertical mixing. Preliminary tests of other\npollutant dispersion models over an urban area indicate that simple models are\nnot satisfactory, except for long-term average concentrations.\nAn improved model of the dispersion and deposition of trace gas and pri-\nmary and secondary aerosols emitted in an urban area was completed under EPA\nspon-sorship. The model was tested using field data obtained in an intensive\nexperimental program conducted by EPA in Philadelphia.\nWork on the theoretical aspects of model evaluation has led to a number\nof related activities. In particular, an assessment is being made of errors\nassociated with the assumption of straight-line Gaussian dispersion at dis-\ntances up to 500 miles, under sponsorship of NRC.\nAn evaluation of near-field Gaussian plume dispersion models developed\nfor assessing the effects of accidental releases of reactive heavy gases was\ncompleted for DOE. This work is of special interest to the operation of\nuranium-processing facilities, which use large quantities of uranium\nhexafluoride.\nThe behavior of the nocturnal planetary boundary layer has become the\nmajor focus of ATDD research on plume dispersion. An acoustic sounder was set\nup and is now in routine operation at the Stone Mountain, Atlanta, observatory\nof the Georgia Institute of Technology. The records obtained will be used\nwith air quality data to investigate the nature of nocturnal turbulence\nintermittency.\nPlans FY 1986\nInvestigations will continue, to develop relatively simple models to simu-\nlate the effects of complex urban wind fields on pollutant dispersion.\nThe collaboration with Georgia Institute of Technology will be extended\nto apply the automatic video digitization techniques developed earlier at ATDD.\nThe methodology will be used to reduce and interpret observations of arctic\nARL\nhaze to be obtained during aircraft missions conducted in collaboration with\nGMCC.\nThe benefits of coupling direct observations of atmospheric turbulence\nwith air quality data to investigate nocturnal intermittency will be further\nexplored. Turbulence data obtained in the operation of monitoring stations\nunder the Dry Deposition component of the ATDD research program will be used.\n167","DISPERSION IN COMPLEX TERRAIN\nAccomplishments FY 1985\nARL participated in the DOE Atmospheric Studies in Complex Terrain\n(ASCOT) dispersion experiments in September-October 1984 in Brush Creek\nValley, Colo. Three perfluorocarbon tracers were released during the night to\ndelineate nochturnal drainage flows and early-morning flow reversal and vent-\ning of pollutants out of the valley. The data will be used in developing\ndispersion models for these flows, which have a high potential for producing\nunacceptable air pollution levels. A three-dimensional katabatic flow model\nhas been developed and tested against ASCOT data.\nReduction of field data obtained in the September-October 1984 ASCOT\nfield experiment was mostly completed. ATDD provided considerable organiza-\ntional input, a role that is of increasing importance as management of the\nASCOT program is gradually moved from Lawrence Livermore National Laboratory\n(LLNL) to Los Alamos National Laboratory (LANL), with ATDD managing field\noperations of the program. In addition, considerable attention was given to\nquality control and quality assurance of the data generated, with the assist-\nance of the EPA Meteorology and Assessment Division and personnel from LLNL\nand LANL.\nThe Complex Terrain Model Development Program is a multiyear effort to\nexamine and model the effect of powerplant plumes in mountainous terrain.\nThe prime contractor, the Wave Propagation Laboratory (WPL) and ARL's Field\nResearch Division have participated in the three field programs over several\nyears, at Cinder Cone Butte in Idaho, Hogback Ridge in New Mexico, and the\nTracy Power Plant near Reno, Nev. In the Hogback Ridge and Tracy Power Plant\nfield studies ARL disseminated a visible oil-fog and two invisible tracer\ngases and analyzed up to 1100 dual tracer-samples for each experiment-day.\nARL also measured wind and/or temperature, using radars, tethersondes, and\nsmall towers.\nThe Meteorology Division computed and placed on magnetic tape the meteoro-\nlogical and tracer gas data base from the Hogback Ridge study, and documented\ndescriptions of the data tape files. The data base is available on tape or by\ninteractive computer access.\nThe latest ERT reports indicate that the basic modeling concept, that of\na dividing streamline height, developed initially for an isolated hill, is\nalso essentially valid for flow over long ridges and mixed complex-terrain\nfeatures. The current version of the Complex Terrain Diffusion Model (CTDM)\ndivides plumes into elements that go around and/or over terrain obstacles.\nTests of the model against measured tracer concentrations demonstrate improved\nperformance over contemporary models and the need for on-site meteorological\nmeasurements. The current version of CTDM has been adapted to run on a micro-\ncomputer, making a useful and convenient tool for further model development\nand evaluation.\nThe Green River Ambient Model Development Program was completed with the\ndelivery of two initial air quality models. One model is designed for applica-\ntion when pollutants are carried in locally developed circulations within a\n168","deep valley flow decoupled from the flow above the valley. The other model is\ndesigned for application to mesoscale transport of air pollutants over the\ncomplex-terrain region of the Green River oil shale formation of Colorado,\nUtah, and Wyoming. Both models are initial working versions for very compli-\ncated situations, and there is a continued need for model evaluation and\nimprovement.\nEight complex-terrain dispersion models were reviewed. An outside con\ntractor calculated and tabulated a uniform set of performance statistics.\nThree Meteorology Division reviewers then evaluated each model, using the\nstandard performance data and technical information from the User's Guides.\nUnder a cooperative agreement, the American Meteorological Society reported\nthe results of the Meteorology Division scientific reviews.\nPlans FY 1986\nResponsibility for planning and organizing large, multilaboratory field\nexperiments for the ASCOT program now resides with ATDD. Plans for the next\nmajor field study will be drafted during FY 1986, and exploratory investiga-\ntions will begin.\nThe ASCOT program also encourages smaller single-laboratory field studies\ndesigned to test specific features of models. Plans will be prepared to con-\nduct such a study at a coastal location of practical importance, suitable for\ntesting the three-dimensional models already developed under this program.\nWind tunnel investigations of enhanced dispersion due to the presence of large\nbuildings will be completed. The results will be incorporated in the heavy-\ngas puff dispersion and transport model being developed under ASCOT's Plume\nDispersion component.\nWork will continue on the development and evaluation of the Complex\nTerrain Diffusion Model, using the field data collected at Cinder Cone Butte,\nHogback Ridge, and the Tracy Power Plant, and data collected during physical\nmodeling experiments in the Fluid Modeling Facility. A study will be initi-\nated on the evaluation and improvement of dispersion models for use on the\nAlaskan North Slope.\nAIR QUALITY DISPERSION MODELING\nARL\nAccomplishments FY 1985\nTechnical assistance was provided to the People's Republic of Chin (PRC)\nthrough the sponsorship of the United Nations World Health Organization. This\nprogram consisted of reviewing PRC environmental monitoring and research pro-\ngrams, and providing lectures on measurement principles and practices, state-\nof-the-art sampling technology, and current dispersion concepts and models,\nwith emphasis on dispersion in complex terrain and on regional-scale problems\nassociated with coal-fired powerplants. The primary host was the Atmospheric\n169","and Environmental Research and Monitoring Center, the major research arm of\nthe PRC's Ministry of Water Resources and Electric Power.\nThe Regional Oxidant Model (ROM) was applied to a series of hypothetical\nproblems whose exact solutions are known. Model predictions and known solu-\ntions were compared, to assess the accuracies of numerical algorithms. For\nozone, the solutions of the model's numerical algorithms are within 10% of the\ncorresponding solutions of differential equations that describe the chemical\nand physical processes that the model simulates.\nAn improved first-generation ROM was applied to data for a 2-day period,\nto demonstrate the model's usefulness in evaluating the effect of urban con-\ntrol strategies on rural ozone concentrations. The base case results, which\nused the 1979 Northeast Corridor Regional Modeling Program emission data, were\ncompared with control strategy results in which the 1979 emission rates were\nmodified on a country basis. The results were used to make a preliminary as-\nsessment of the impact on ozone concentration of projected 1987 hydrocarbon\nand NO emission reductions (about 32% and 8%, respectively) over the north-\neastern United States. It was found that ozone concentrations in the control\ncase were everywhere lower than those in the base case, but the percentages\nwere not uniform in space. In urban and suburban areas the maximum hourly\naverage was about 35% lower; in rural locations the predicted peak was only\nabout 20% lower. Emission control reduced peak concentrations by considerably\nlarger percentage than it reduced the median or mean values.\nA major portion of the oxidant modeling of the New York Metropolitan Area\nwas completed, including (1) transfer of air quality and meteorological data\nbases to the New York State Department of Environmental Conservation; (2)\nselection of five candidate modeling days; (3) development of ambient and emis-\nsion inputs; and (4) application of the Airshed Photochemical Model (APM) for\nthe first base-case simulation. An interim report described the procedures\nemployed for deriving the air quality and meteorological inputs necessary to\napply APM to the tri-state New York Metropolitan Area. The results of this\nproject will be used to determine the need for further emission controls, to\nattain the ozone National Ambient Air Quality Standard in this area.\nTwo feasibility modeling studies were conducted to provide preliminary\ninformation on regional-scale ozone predictions in support of the EPA Ozone\nRegulatory Impact Analysis. The two studies included an example application\nof the Regional Transport Model and initial simulations with the first-genera-\ntion ROM. Specific applications of the second-generation versions of both\nmodels are planned, to provide estimates of the change in regional ozone con-\ncentrations for alternative volatile organic chemicals and NO emission con-\ntrol scenarios for various regions of the United States.\nA cooperative agreement with the Microelectronics Center of North\nCarolina was funded to explore ways of implementing large model codes such as\nthe ROM and the Regional Acid Deposition Model (RADM) in custom computer chips.\nThe research is directed toward operation of large, complex, dispersion models\non mini- and microcomputers, thereby reducing the running time of the codes\nsubstantially.\nOperations manuals were produced for the Airshed Model, a numerical three-\ndimensional grid model for photochemical air quality applicable to urban\n170","scales. The manuals include a User's Guide and a Systems Manual. The theoret-\nical framework of the model was documented.\nThe final version of the Regional Lagrangian Model of Air Pollution\n(RELMAP), formerly ENAMAP, was applied on a monthly basis for 1980. Monthly,\nseasonal, and annual concentrations and depositions were submitted as part of\nthe International Sulfur Deposition Model Evaluation.\nA preliminary particlersize-discriminant emissions inventory was prepared\nfor initial testing of RELMAP for particulate modeling. Extensive data pro-\ncessing and quality control were performed on the National Acid Precipitation\nAssessment Program (NAPAP) version-4 emissions inventory for application in\nthe ROM and the RADM.\nThe Meteorological Processor for Dispersion Analysis and associated\nuser's guide were completed. The Branching Trajectory Model was enhanced to\nproduce overlays of geographical features on trajectory maps; it was applied\nfor April through October 1982 and 1983 for several sites, to assist Maine's\nAir Bureau in a critical ozone analysis. A parameterization of mixing-depth\nstatistics and analysis of the structure of the turbulent boundary layer was\ncompleted for the Tennessee plume data.\nSeveral studies were completed evaluating a Gaussian air quality model\nknown as RAM and the Climatological Dispersion Model (CDM) with the Regional\nAir Pollution Study data base. The RAM model was found to have a bias toward\nunderpredicting concentrations during the day and overestimating values at\nnight. Although area-source emissions constituted only 3.5% of the total SO2\nemission, the CDM estimates of arearsource contributions to the annual average\nrange from 14% to 67%.\nTo assist EPA's Office of Air Quality Planning and Standards in develop-\ning revised stack height regulations, a short research note was prepared sum-\nmarizing calculations of expected maximum ground-level pollutant concentra-\ntions, together with frequencies with which higher concentrations might occur.\nCalculation were made for conditions of normal dispersion, building wake\neffects, inversion breakup fumigations, limited mixing layers, and plume\nlooping events.\nThe 1980 guideline for determining Good Engineering Stack Height was\nrevised. The revision incorporates (1) recent regulatory requirements; (2)\nresults from recent studies and tests on the applicability of the Good\nEngineering formula; (3) treatment of portions of terrain that may induce down-\nARL\nwash in a wind tunnel simulation; (4) application of air quality modeling when\nthere is high terrain, multiple source impacts, or venting from multiple\nflues.\nModels MPTER, CDM, CRSTER, ISC, and RAM, developed and recommended by\nEPA, are being revised to reflect improvements in modeling techniques and to\nimprove technical consistency among the models. The changes include (1) con-\nsistent formulations of plume rise; (2) treatment of terrain (where appropri-\nate); (3) buoyancy-induc dispersion; (4) revised wind profile exponents; and\n(5) ddi-tion to CRSTER and ISC of the urban dispersion coefficients now in\nthe RAM model.\n171","Three published methods to calculate the standard deviation of wind direc-\ntion, sigmama, were tested, both on tower data and on synthetic data contain-\ning extremes. The method of Yamartino produces results with maximum errors of\n1.2° or 1.5%\nThe experimental and theoretical work on vehicle wakes was completed. A\nuser's manual for the model ROADWAY is being prepared.\nA position paper concerning models of diffusion in atmospheric boundary\nlayers was completed.\nPlans FY 1986\nDirect meteorological research support to EPA will continue with develop-\nment and evaluation of air quality dispersion models for inert and reactive\npollutants and the associated meteorological models on all temporal and spat-\nial scales. An important area of continued concern will be the problems asso-\nciated with model uncertainty and model evaluation procedures. Emphasis in FY\n1986 will be on development of a regional-scale particulate-matter dispersion\nmodel; development and evaluation of a second-generation ROM; examination of\nthe effect of mesoscale convective precipitation systems on ozone transport\nand haze dispersal; and development of custom computer chips for use in\nrunning large, complex models on mini- and microcomputers.\nFLUID MODELING\nAccomplishments FY 1985\nThe Fluid Modeling Facility continued studies using a water channel/tow-\ning tank and one large and several small wind tunnels, in support of EPA re-\nsearch. Studies involved flow in complex terrain, flow through wind screens,\nbuilding wake effects, and stack height.\nA wind tunnel demonstration study on good-engineering-practice stack\nheight was conducted in response to a request from the EPA Office of Air\nQuality Planning and Standards in conjunction with a Federal Appeals Court\nMandate requiring EPA to revise the Stack Height Regulations. A 326-m stack\nwas demonstrated as necessary to avoid wakes, eddies, and downwash caused by\nthe terrain upwind of the Clinch River Power Plant in southwestern Virginia.\nUnder a cooperative agreement with the North Carolina State University, a\nwind tunnel study to examine the effectiveness of screen in reducing wind\nspeeds near storage piles was completed. This provides an intermediate step\nin constructing a mathematical model to predict the effectiveness of the\nscreens in reducing fugitive dust emissions. Various screen types, place-\nments, shapes, and sizes were tested for each of two basic shapes of storage\npiles--a cone shape and a flat-topped pile of roughly elliptical cross section.\nApplication of simple particle-uptake models suggested that screens could be\n172","highly effective in reducing fugitive dust emissions; 90% reductions were\nfairly typical.\nAn initial feasibility study of methodologies for analyzing videotaped\nimages of smokervisualized plumes was successfully completed. Through video\nimage analysis, shortmtime-scale building wake effects on plume dispersion can\nbe studied. The information obtained, along with conventional point measure\nments of tracer concentrations and fluid velocities, is being used to evaluate\nthe overall effects of buildings on plume dispersion.\nA cooperative project was initiated with the Los Alamos National Labora-\ntory to examine the conditions under which flushing of a valley between two\nridges will occur, i.e., to answer the question of when a stable crosswind\nwill sweep the valley clean and when the flow will separate from the top lee\nside of the first ridge, reattach at the top windward side of the second\nridge, and thus form a nearly stagnant region in the valley beneath. The\nfirst phase of a series of towing-tank studies examined the effect of Froude\nnumber (characterizing the stability of the cross wind) and the separation\ndistance between a pair of ridges, where the maximum slope of the valley side-\nwalls was quite steep (40°) The results strongly suggest the need for\nfurther studies with valley sidewalls of smaller slope.\nA large set of streamline trajectories over an axisymmetric hill was meas\nured in the stratified towing tank. Three-dimensional coordinates of the\nstreamlines were determined through stereographic analysis of photographs of\nstreak lines of dye released at a matrix of source positions (heights and\nlateral offsets from the hill/flow centerline), and at stabilities ranging\nfrom strongly stable to neutral.\nPrevious towing-tank and wind-tunnel measurements of concentration distri-\nbutions on the surface of a hill when a plume impinges from an upwind source\nwere published. The major results were that (1) when the source is below the\ndividing-streamline height (HD), the plumes impact on the windward hill sur-\nface and yield maximum surface concentrations nearly the same as would be ob-\nserved at the plume centerline in the absence of the hill; (2) when the source\nis above HD, the plume surmounts the hill top, but if it is only slightly\nabove HD, the maximum surface concentrations can again essentially equal those\nat plume centerline in the absence of the hill; (3) the location and value of\nthe maximum surface concentration is extremely sensitive to slight displace\nments of the source from the stagnation streamline when the source is below\nHD.\nARL\nTerrain amplification factors were measured for a large matrix of source\npositions (locations and heights) both upstream and downstream of each of two\nidealized hills: an axisymmetric hill, and a two-dimensional ridge. The re-\nsults showed that \"windows\" of 40% excess concentration extend to 1.8 hill\nheights (h) in the vertical, 14h upstream, and 10h downstream for the three-\ndimensional hill, and 2.2h in the vertical, 8h upstream, and 15h downstream\nfor the two-dimensional ridge. Maximum terrain amplification factors were\nfound O the downstream sides of the hills; values were 6.8 and 5.6 for the 2-D\nand 3-D hills, respectively.\nUnder an interagency agreement with the Oak Ridge National Laboratory,\nwind tunnel measurements were conducted to examine the flow fields and concen-\n173","tration patterns resulting from sources upwind of a series of ramps (followed\nby plateau) of various slopes and crosswind aspect ratios. Data reports and\npreliminary analyses were completed.\nThe flow fields around moderately steep hills of triangular cross section\nand varying crosswind aspect ratio were examined using models immersed in a\nsimulated atmospheric boundary layer in the wind tunnel. Concentration pat-\nterns resulting from sources placed upwind of each of these hills showed\nstrong plume deformations, and terrain amplification factors generally in-\ncreased with decreasing aspect ratio.\nA cooperative project with the Los Alamos National Laboratory was con-\ncluded with the preparation of a report on Monte Carlo simulation of two-\nparticle relative diffusion using Eulerian statistics. Detailed measurements\nof low characteristics downstream of a curbulence-generating grid were used as\na basis for calculating particle diffusion. Results of the calculations were\ncompared with total diffusion measured by a hydrocarbon tracer technique and\nwith relative diffusion determined from analysis of near-instantaneous photo-\ngraphs of smoke plumes. Comparisons between a one-particle diffusion model\nand the present two-particle model showed that the two-particle model provided\na more accurate description of plume meandering and relative diffusion.\nPlans FY 1986\nWork will continue in the Fluid Modeling Facility, using the wind tunnels\nand water channel/towing tank, on the study of flow in complex terrain and\naround buildings and other obstacles.\nACID DEPOSITION\nAccomplishments FY 1985\nThe acid rain problem has continued to be a very important area of re-\nsearch and a major concern of the U.S. public. Evidence of forest and lake\ndamage in both North America and Europe is still being evaluated, and research\nindicates that the environmental attacks are not limited to acid precipitation\nbut include dry deposition of aerosols and gases, particularly ozone. ARL has\na leadership role in the Federal acid rain program, to study all aspects of\nproblems involving the atmosphere. International cooperation, especially with\nCanadian and European scientists, has been maintained at a high level.\nResearch in precipitation chemistry made notable progress:\nAerosol and gas measurements were made along the mid-Atlantic\ncoast and at Bermuda during a major WATOX field experiment. (See\nAtmospheric Transport for details.)\nThe Global Trends Network showed that seasalt corrections in\nprecipitation chemistry involve several complex assumptions, and that\n174","appropriate reference species (e.g., Mg+2, Na+) must be selected using\nobjective criteria.\nTwo meetings with representatives from the People's Republic of China\nresulted in plans for the establishment of a precipitation chemistry\nstation in western China during FY 1986.\nA special study was carried out to evaluate inflow of dimethyl\nsulfone, a naturally occurring sulfur compound from the Gulf of Mexico.\n(See Atmospheric Transport for details.)\nSpecial studies at the atmospheric research sites included con\ntinued application of isotropic trajectory modeling to precipitation\ndata bases, and the evaluation of evaporation losses from the automatic\nprecipitation collectors used in the NOAA/EPA/World Meteorological\nOrganization (WMO) precipitation chemistry network between 1972 and\n1980.\nThe NOAA precipitation data for both remote and continental U.S.\nlocations, collected between 1972 and 1982, were published.\nRoutine operation of 15 National Trends Network precipitation\nchemistry stations continued. A full year of data from two pairs of\ncolocated stations in Texas and Maine has now been collected.\nPlans FY 1986\nOngoing activities will be supplemented by the following new activities:\nA major WATOX field experiment during January 1985 will obtain\nmeasurements with the King Air and the NOAA P-3 along the central\nAtlantic and New England coasts.\nIn cooperation with EPA, a remote station in western China will begin\noperating as part of the Global Precipitation Chemistry Program.\nDRY DEPOSITION\nARL\nAccomplishments FY 1985\nSeveral new stations were added to the dry deposition pilot monitoring\nnetwork, at Champaign/Urbana, Ill. (in collaboration with the Illinois State\nWater Survey), Panola State Park, Ga. (in support of watershed studies by the\nU. S. Geological Survey), and Borden, Ontario (in cooperation with the\nCanadian Atmospheric Environment Service). Data obtained in the first year's\noperation of the original five sites were reduced. These preliminary data\nindicate that at most locations dry deposition rates of sulfur exceed wet depo-\nsition rates.\n175","The computer analysis routine by which deposition velocities are derived\nfrom measurements of selected meteorological and surface properties has been\nexercised routinely as a part of the pilot dry deposition monitoring program.\nThis computer model is viewed as a firstogeneration development, to be up-\ngraded as more results become available from the ongoing field programs con-\nducted under the Core research program.\nThe series of comparison studies involving the laboratories of the Core\nresearch program continued, recent attention being directed to the problem of\ndeposition to snow and to mature corn. Periodic site-specific investigations\nof dry deposition fluxes are now routine at each of the Core sites (Oak Ridge,\nTenn. ; Argonne, Ill. ; and State College, Pa.), so as to provide \"benchmarks\"\nfor evaluating the estimates of dry deposition obtained using simpler\ntechniques.\nIn March 1985, an intensive field study of sulfur eddy fluxes was conduc-\nted over a grass field and subsequently over a spruce forest in West Germany.\nFor the first time two nearly identical sets of sulfur-sensing apparatus were\noperated side-by-side for an extensive period. The data obtained show good\nagreement between the two systems. A procedure for directly quantifying the\nerror associated with individual half-hour averages of eddy fluxes was tested\nand is now part of the routine eddy flux measurement program a applied by ATDD.\nThe opportunity was also taken to evaluate the effect of artifact signals on\ndeterminations of sulfur eddy fluxes. Several reports have described the\nresults of this field study, conducted in conjunction with studies in the\nstate of Baden-Württemberg, in southwestern Germany.\nPlans FY 1986\nThe model now in place for deriving deposition velocities from measured\nmeteorological and surface information will be further tested and improved.\nThe series of Core station comparison experiments will continue with a major\nmultilaboratory study at the forest meteorology research facility in Oak\nRidge. Two dry-deposition pilot stations will be added. The Core network\nwill also be expanded slowly with support from EPA.\nACID RAIN MODELING\nAccomplishments FY 1985\nA major effort continues, in support of the EPA research program, to\ndevelop and evaluate regional and mesoscale acid deposition models. As part\nof this program, under an agreement with the National Science Foundation,\na\ncomprehensive regional model is being developed at the National Center for\nAtmospheric Research (NCAR). Development of component modules, under agree-\nments with several DOE National Laboratories, continued with both field\nstudies and numerical modeling activities.\n176","A preliminary version of the Regional Acid Deposition Model (RADM) being\ndeveloped at NCAR was completed and received favorable peer review. The RADM\nis being subjected to extensive sensitivity analyses and preliminary\nevaluation.\nIn cooperation with the U.S./Canadian Technical Committee for Eulerian\nAcid Deposition Modeling, a conceptual plan for performance evaluation of re-\ngional acid deposition models was developed and favorably reviewed. The plan\nproposes a major field program consisting of a 50-station long-term surface\nwet deposition and ambient air quality network and four 1-month intensive\nfield programs starting in the spring of 1987.\nThe acid precipitation mesoscale project has shown that urban-industrial\nareas make significant contributions to the acidity of downwind precipitation.\nPreliminary results from the May 1985 field study confirm that there can be\nlarge differences in this contribution on an event basis, especially for nin\ntrates. The sulfate contribution appears to be due to aqueous conversion of\nSO,\nA standard set of 1980 model input and output data was created and used\nto compare and evaluate the performance of 13 regional longeterm acid deposi-\ntion models for seasonal and annual wet deposition amounts across eastern\nNorth America. Preliminary results suggest that these models, all of which\nuse simple linear parameterizations of acidic processes, reasonably replicate\nwet deposition patterns; however, maximum deposition appears to be displaced\nseveral hundred kilometers eastward\nA statistical study demonstrated similar trends in the monthly SO2 emish\nsions from the electric utility industry and monthly average ambient SO2 con-\ncentrations in the northeastern United States from 1975 through 1982. The\nstudy also investigated the correlation between seasonally adjusted emissions\nand ambient concentrations at the local, state, and regional levels.\nStatistical techniques, including Kriging, were used to analyze spatial\npatterns of wet deposition data from Canada and the United States for 1980-\n1983. Maps of concentration and deposition of SO4, NO 3, and H ions were pre-\npared and examined for significant temporal trends.\nField experiments for VENTEX (Venting Experiment) were conducted to study\nthe transport and transformation of acidic compounds by nonprecipitating\ncumulus convective processes, and to provide the observational bases for the\ndevelopmentof parameterized models for inclusion as process computer modules\nARL\nfor the RADM. Vertical exchange between the mixed layer and the overlying\nfree troposphere was found to be enhanced by the presence of cumulus convec-\ntive clouds, especially those having significant vertical development. This\nconclusion was reached through the analysis of inert tracer data, which showed\nsignificant concentrations of the tracer at the surface and in the mixed layer\nsoon after release at the altitude of the prevailing cumulus cloud tops. A\nfirstgeneration cumulus transport module was developed for inclusion in the\nRADM.\nThe release of fluorescent dye particles and subsequent tracking by an\nairborne two-wavelength backscatter lidar system was demonstrated to be feas-\nible and useful as a marker for air parcels in transport and transformation\n177","studies on local and regional scales. This method was first tested by SRI in\n1983. This year it was successfully used in VENTEX summer field studies of\nvertical transport processes by cumulus convective clouds, as well as regional-\nscale transport studies.\nPlans FY 1986\nWork on the development of the RADM and its module will continue.\nDetailed design development and other preparation will continue for a major\nfield program in 1987 to obtain a data base for evaluating regional models.\nWith the assistance of NASA and Brookhaven National Laboratory, development\nand evaluation of the mesoscale acid deposition and assessment model will con-\ntinue. The International Sulfur Deposition Model Evaluation (ISDME) will be\ncompleted.\nATMOSPHERE-CANOPY INTERACTION\n(FOREST METEOROLOGY)\nAccomplishments FY 1985\nClimatological monitoring and data reduction at the forest meteorology\nresearch site continued, with some modification due to the need for additional\ndata for other program components.\nThe seasonal variation in the statistics of radiation penetration into\nthe canopy was analyzed and used to evaluate several canopy phytoactinometric\nmodels. Under partial sponsorship of DOD, intensive studies of the thermal\nradiation distribution above and in the forest canopy were completed.\nIrregular radiative heating of the surface results from the different\nexposures imposed by terrain complexity (slopes with a southern exposure re-\nceive more radiation then do those facing north, for example). The consequen-\nces were detected as apparent imbalances in the surface heat energy budget as\ndeduced from eddy fluxes measured at the forest meteorology research site.\nA multilevel canopy stomatal conductance model was developed as an ini-\ntial step toward generating an advanced atmospherencanopy exchange model.\nSuch a model would be suitable for describing details of the source/sink dis-\ntributions within the canopy, and for guidance in studies of surface parameter-\nization. In this regard, it is becoming increasingly clear that a balanced\nparameterization scheme is required, coupling aspects of biology with surface\nphysics and chemistry as well as involving atmospheric turbulence.\nField data on the eddy fluxes of heat, momentum, and mass obtained in\nintensive studies conducted periodically at the forest meteorology research\nsite were used in the development of the sub-canopy model. Particular success\nwas attained in the case of carbon dioxide (CO2). A collaborative experiment\nwith the University of Nebraska successfully demonstrated that CO 2 fluxes can\nbe measured at the forest floor as well as above it. The CO2 exchange rates\n178","between the canopy and the atmosphere were much as expected from other measure-\nment programs. These data are being used to evaluate the overall surface-\ninteraction model which, when proved, will provide the desired capability to\nextend such single=surface eddy flux observations to other situations.\nPlans FY 1986\nThe multilayer subcanopy photosynthetic model already in existence will\nbe coupled with a detailed subcanopy turbulence model, in order to provide a\nfirst-generation simulation of pollutant movement through canopies and into\nplant tissue.\nFurther experimental investigations of turbulent statistics and flux\nparameterizations above and within the forest canopy will be conducted. The\npenetration of gusts into the canopy and the resulting subcanopy flow fields\nwill be addressed in field experiments.\nMeasurement programs will continue; the data obtained are also of inter-\nest to workers at Oak Ridge National Laboratory and to those involved in the\ndry deposition research programs at the Core site in Oak Ridge.\nOZONE\nAccomplishments FY 1985\nWith funding from the National Environmental Satellite, Data, and Infor-\nmation Service (NESDIS), the GMCC Division began ozonesonde, Umkehr, and total-\nozone monitoring programs late in 1984 to provide NESDIS with ground- and\nballoonmbased ozone data for use in validating SBUV-2 ozone data obtained\naboard the NOAA-F satellite. The work is expected to continue during the next\nseveral years as other NOAA satellites carrying SBUV ozone instrumentation are\nlaunched.\nNESDIS has identified 16 select Dobson spectrophotometer stations whose\ntotal-ozone data will be used for the validations. GMCC has agreed to help\nmaintain calibration of the Dobson instruments at these sites to ensure that\ntotal-ozone observations are of high quality. The stations are in Arosa,\nARL\nSwitzerland; Boulder, Colo. Edmonton, Canada; Goosebay, Canada; Huancayo,\nPeru; Haute Provence, France; Invercargill (or Lauder), New Zealand; Mauna\nLoa, Hawaii; Melbourne, Australia; New Delhi, India; Perth, Australia; Poker\nFlat, Alaska; Pretoria, South Africa; Sapporo, Japan; Tateno, Japan; and\nVaranasi, India. In December 1984, GMCC conducted an International Inter-\ncomparison of Dobson ozone spectrophotometers at Melbourne under the auspices\nof the WMO, at which time the Melbourne, Invercargill, New Delhi, and Tateno\nDobson instruments were calibrated relative to World Standard Dobson instru-\nment No. 83 maintained by GMCC. Of the remaining select total-ozone stations,\nonly Arosa, Sapporo, and Varanasi require Dobson instrument calibrations in\n1986.\n179","Apart from the stations named above, total-ozone observations with Dobson\nspectrophotometers continued during FY 1985 at Bismarck, N. Dak. ; Caribou,\nMaine; American Samoa; Tallahassee, Fla.; Nashville, Tenn.; South Pole;\nWallops Island, Va. ; and Fresno, Calif.\nThe GMCC Dobson spectrophotometer Central Laboratory in Boulder continued\nto upgrade and calibrate Dobson instruments in the global total-ozone station\nnetworks. In addition to the instruments calibrated at Melbourne, two\nAustralian instruments and one United Kingdom instrument were calibrated.\nWeekly observations of ozone vertical distribution to about 40 km alti-\ntude with electrochemical concentration cell (ECC) ozonesondes commenced at\nBoulder and Hilo, Hawaii, in early 1984. A third station, at Edmonton, was\nadded to the network in August 1985 in a cooperative effort between GMCC and\nthe Atmospheric Environment Service of Canada.\nUmkehr observations with automated Dobson ozone spectrophotometers were\ncontinued during FY 1984 at Boulder, Haute Provence Observatory, Poker Flat,\nMauna Loa Observatory, and Perth. A sixth automated Dobson instrument became\noperational at Huancayo in September 1985.\nTotal-ozone and ozone-profile data for the world were updated through the\nautumn of 1984. Ground-based and satellite measurements show that total ozone\nreturned nearly to average following anomalously low values in early 1983. In\nthe north temperate zone where most of the ozone stations are located, total\nozone was 1% above average in 1984 compared with 4% below average in 1983. In\nthe 16H24 km layer of the low stratosphere where the ozone reduction was most\npronounced, the ozone amount was 6% below average in 1984 compared with 13%\nbelow average in 1983. In the 32-48 km layer of the high stratosphere, Umkehr\ndata indicate an ozone amount 8% below average in 1983 and 3% below average in\n1984, but the 1984 data may still be biased by the aerosols from the El\nChichon volcanic eruption in the spring of 1982. Ozonesonde data suggest only\na 1% increase in tropospheric ozone between 1983 and 1984. It is still uncer-\ntain whether the anomalously low ozone values in early 1983 were due to atmos-\npheric circulation changes induced by the 1982-83 El Niño or, directly or in-\ndirectly, to volcanic aerosols injected into the atmosphere by El Chichon.\nPlans FY 1986\nDobson ozone spectrophotometers operated at Sapporo and Varanasi will be\nreconditioned and recalibrated. A program carried out in 1981 to check the\ncalibration status of Dobson spectrophotometers in the network, using travel-\ning, calibrated standard lamps, is being repeated. Test results from all sta-\ntions are expected to be received in Boulder by late 1986. An automated\nDobson instrument will be installed for Umkehr observations at Lauder in\nJanuary 1986.\nUmkehr measurements will be analyzed for information on ozone profile\nvariations and tendencies on much shorter time scales, using automated Dobson\ndata. The results of the Umkehr analysis will be compared with SBUV profiles,\nobserved concurrently with the Umkehr, to determine the agreement that is now\nachievable with the two systems. This study will include an investigation of\n180","Umkehr measurement noise from thin clouds, and possibly aerosols, in the\nzenith-sky field of view.\nStations at Poker Flat and South Pole will be added to the ozonesonde\nnetwork. Research will be conducted to couple ECC ozonesondes to hypsometer\nradiosondes in a manner that will permit real-time, automated processing of\nthe ozonesonde data. Use of substantial numbers of ECC ozonesondes is en-\nvisioned for tropospheric ozone studies.\nThe total-ozone data and ozone-profile data will continue to be updated\nto confirm that the recent ozone decrease was indeed temporary and does not,\nin part, reflect anthropogenic influences on stratospheric photochemistry.\nCLIMATE\nSUN- AND MOON-CLIMATE RELATIONSHIPS\nAccomplishments FY 1985\nThe University of Arizona, under an ARL grant, has been testing a solar\nspectrometer at Mt. Lemon and at the University of Arizona campus in Tucson.\nThis device is designed to measure, from the Earth's surface, variations in\nthe\n\"solar constant\" after adjustment for intervening atmospheric effects.\nAnalysis of solar UV spectral irradiance measurements from the Nimbus-7,\nSME, and AE-E satellites identified three time scales of UV radiation varia-\ntions important to the stratosphere and caused by solar activity variations:\n(1) short-term variations (days, weeks), caused by the solar rotation of solar\nactive regions distributed nonuniformly in solar longitude, that are quasi-\nperiodic, having periods near 13 and 28 days; (2) intermediate-term variations\n(4-8 months) caused by episodes of major activity, and (3) long-term varia-\ntions (years) caused by the buildup of solar active regions, their long-lived\nremnants and/or the active solar network over a solar cycle. The annual varia-\ntion in all-solar radiation caused by the Sun-Earth distance variations is a\nlittle less than 7% above the minimum value, and that of the observed varia-\ntions in the total solar irradiance is a few tenths of 1%. Using the long\nterm relation of the 205-nm flux with respect to the 1083-nm He I line observa-\ntions, we estimate that the 205mmm flux increases by about 8% from the minimum\nARL\nto maximum for solar cycle 21 for annual average values, by about 10% for\nmonthly mean value (including long- and intermediatenterm variations), and by\nabout 13% for daily values (including short-term variations). The largest\n27-day short=term increase was about 7%, comparable with the annual\nvariations.\nThe intermediate-term variations of the solar UV and the 1083-nm chromo-\nspheric-line fluxes were shown to rise slower, peak later, and decay slower\nthan those of the classical indices of solar activity, namely the sunspot\nnumber and Ca-K plage index. This is because the photospheric and chromos-\nspheric plages and plage remnants have a slower evolution than their associ-\nated sunspots, coronal active regions, and initial major plages.\n181","The SBUV/2 measurements of solar UV spectral irradiance were analyzed for\nApril 1985, the only month of data released by NOAA-NESDIS.\nSolar UV flux variations are a routinely monitored quantity. The ozone\nvariations caused by these variations were identified, measured (mainly by\nscientists outside of NOAA), and shown to be in good agreement with theory,\nwhere the main point of controversy is the timing in the upper stratosphere\nbrought about by the interplay of increased ozone production through UV-\ninduced increases in atomic oxygen combined with delayed temperature increases\nthat cause increased ozone destruction.\nThe main calibrations of the solar UV spectroradiometers were completed\nin collaboration with scientists at the National Bureau of Standards (NBS) in\nGaithersburg, Md. These spectroradiometers were then used in laboratory ex-\nperiments to show that the NBS tungsten-lamp radiation standards, which are\nnormally used at visible wavelengths, and measurements from the NBS\nSynchrotron Ultraviolet Radiation Facility (SURF), which is normally used at\nultraviolet and extreme ultraviolet wavelengths, agree within about 1% at\nmiddle-UV wavelengths.\nAn analysis was completed of the sensitivity of U.S. summer precipitation\nto the position of the Moon in its orbit. Prior studies have shown that a\nmaximum in precipitation occurs about 4 days after new moon and a minimum\noccurs about a week later, considering the United States as a whole. The\npresent analysis shows that in summer these effects do not occur simultan-\neously but rather appear first in the northwest and, over a 2-week period,\npropagate to the southeastern United States. The maximum frequency of occur-\nrence of summer precipitation occurs in the northwest about 5 days before new\nmoon, and reaches the southeast about 6 days before full moon. The minimum\noccurs about a week after maximum in most regions of the U.S., except the por-\ntions of the southwest that receive little or no summer precipitation.\nThe fact that lunar modulation of precipitation does not occur simultane-\nously over the United States suggests that a previous theory explaining lunar\neffects on precipitation through modulation of galactic cosmic ray is either\nincorrect or must be modified. Our tentative hypothesis is that lunar posi-\ntion affects summer precipitation in the United States through changes in trop-\nospheric circulation--induced either in the Gulf of Alaska by modulation of\nsynoptic-scale systems, or by modification of large-scale convection in the\ntropics and subtropics.\nThe change in precipitation over the lunar period is, in some regions,\nrelatively large. Summer precipitation in Colorado and Wyoming varies by a\nfactor of 2 over the lunar synodic period. Analysis confirmed the published\nevidence of additional systematic variation in precipitation over the lunar\nsynodic period, delayed by about 2 weeks relative to the indicated cycle.\nStudies are in progress on solar and lunar effects on tropospheric vari-\nables such as vorticity area index, zonal atmospheric angular momentum, and\ntornado frequency.\n182","Plans FY 1986\nThe University of Arizona plans to deploy the solar spectrometer at Mauna\nLoa Observatory in late 1985 for support of ARL research.\nAnalysis of solar UV spectral irradiance in the 160-400 nm range from the\nSBUV/2 monitor aboard the NOAA-9 satellite will continue. Analysis of\nNimbus-7, SME, and AE-E satellite measurements of solar UV flux variations\nwill be completed except for future comparisons with SBUV/2-NOAA-9\nmeasurements.\nTwo special sessions will be held at the fall meeting of the American\nGeophysical Union: Stratospheric, Mesospheric and Thermospheric Effects of\nSolar Variability; and Solar Variability. Research on coupling of the strato-\nspheric effects of solar UV variability into the troposphere will be\nincreased.\nResearch will continue on solar/lunar forcing and changing conditions in\nthe troposphere. Specifically, a tentative hypothesis will be tested explain-\ning lunar effects on summer precipitation over the United States in terms of\neffects 2n tropospheric circulation. The statistical significance of the\nrelationship between lunar position and tropospheric variables will be\nevaluated. Discussions will continue with the National Weather Service (NWS)\nTechniques Development Laboratory on the possible application of these\nanalyses to prediction of precipitation over the United States.\nSOLAR RADIATION FACILITY\nAccomplishments FY 1985\nFunding was obtained for upgrading data acquisition and solar tracking\nunits at 31 U.S. weather stations. NWS purchased computers for data acquisi-\ntion, and ERL issued a Request for Proposals for automatic solar trackers that\nwill be maintained by GMCC's Solar Radiation Facility.\nThere are now 40 two-wavelength sunphotometers either in operation at U.S.\nstations and GMCC observatories or on loan. Approximately 24 station years of\ndata have been acquired since the upgrade of the turbidity network. The pro-\nARL\ncedure for calibrating these instruments has been tested and deemed feasible.\nIt consists of calibrating precision sunphotometers at Mauna Loa Observatory\nand using this instrument at Boulder to calibrate the U.S. network\ninstruments.\nPlans FY 1986\nTwo fiverwavelength precision sunphotometers will be tested and placed\ninto service to calibrate the two-wavelength U.S. network sunphotometers.\nThese instruments will also be used as reference standards at Mauna Loa\nObservatory when the site is used for special testing and calibration of\n183","instruments from sources outside NOAA. WMO has recommended Mauna Loa Observa-\ntory as one of two world facilities for testing and calibrating turbidity\nsunphotometers.\nThe new data acquisition and tracking instrumentation for the U.S. Solar\nRadiation Network will be installed by NWS and ERL. Installation will be\nfollowed by performance evaluation checks and close scrutiny of data products\nto be transmitted by NWS.\nAEROSOLS AND RADIATION\nAccomplishments FY 1985\nTotal radiation balance measurements were begun at Barrow Observatory.\nThe measurements are being made a shorter distance from the Observatory build-\nings and are representative of only a particular surface-type local dry tundra\nduring the summer but for about eight months of the year should be represen-\ntative of nearly synoptic-scale arctic surface. Knowledge of the radiation\nbalance at Barrow will be useful for studies of local climatic conditions and\nregional climatic variations.\nA clear-sky solar radiation model originally developed at SERI (Solar\nEnergy Research Institute, Golden, Colo.) was adapted to the existing condi-\ntions at the GMCC observatories. The model was then run to produce detailed\nclear-sky radiation climatologies for the observatories against which real-\ntime observations could be compared. The principal purpose for the comparison\nis data quality control and testing of our ability to model clear-sky radia-\ntion at these sites.\nThe apparent atmospheric transmission procedure for monitoring aerosol\nloading with a pyrheliometer was examined for water vapor effects, using an\natmospheric transmission model. Water vapor data used in the study were ob-\ntained from a dual-channel sunphotometer operated continuously at Mauna Loa\nfor 6 years. It was shown that 25% of the day-to-day variance could be attrib-\nuted to water vapor.\nAerosol measurements at Barrow show a repeatable annual cycle with a maxi-\nmum in spring and a minimum in summer. The maximum in the spring, known as\nthe arctic haze, was shown to be a result of longerange transport of anthro-\npogenic pollution aerosol from the middle latitudes, primarily Eurasia and\ncentral Asia.\nAerosol measurements at Mauna Loa show a repeatable annual cycle with a\nmaximum in late spring and a minimum in winter. The maximum in late spring\nwas shown to be a result of long-range transport of dust from the deserts of\nAsia during times of vigorous dust storms and efficient transport.\nAerosol measurements at America Samoa show a scattering function that\nincreases with increasing wavelength, unlike scattering at other GMCC sites,\nwhich decreases with increasing wavelength. Aerosol size distribution measure-\nments and Mie scattering calculations showed that the scattering measurements\n184","can be explained by an aerosol size distribution with a large sea-salt mode\nand smaller sulfate mode.\nAerosol measurements at the South Pole show that aerosol sulfur and con-\ndensation nucleus (CN) concentrations have an annual cycle with a maximum in\naustral summer and a minimum in winter. Aerosol scattering and sodium concen-\ntrations have a cycle with a minimum in the summer and a series of high values\nin the late winter. Analysis showed that sea-salt events occur when winter\nstorms cause rapid transport of aerosol from coastal regions, and an accompany-\ning warming and decrease in the strength of the surface temperature inversion\nenhances vertical transport to the surface.\nMeasurements of CN concentration and aerosol scattering continued at\nWhiteface Mountain during the summer of 1985. Haziest episodes occur during\nperiods of high pressure when air is coming from the direction of the indus-\ntrial areas of the Great Lakes regions.\nMauna Loa Observatory lidar data were reduced and analyzed in parametric\nform for features and variations in profile. The lidar data record extends\nfrom late 1974 to the present. The Mauna Loa lidar data were compared with\nLangley, Va., lidar data for nearly the same time period. The measurements\nwere quite similar, and stratospheric aerosol error correction factors to\nUmkehr ozone profiles appeared reasonable, at least for data from Mauna Loa\nfor the time period 1975-1981. Of course, lidar observations at higher lati-\ntudes will help reduce uncertainties associated with the use of Mauna Loa data\nonly when correcting Umkehr observations.\nPlans FY 1986\nTotal radiation balance measurements will be made 15 miles east of\nBoulder on top of the Boulder Atmospheric Observatory tower (900 ft above\nground). The measurement program will include real-time data reduction and\ntransmission to ERL research offices. The downwardeviewing global instrumen-\ntation will integrate a signal over a diverse land surface area representative\nof the Colorado eastern plains comparable with the area viewed by satellites.\nHightime-resolution measurements will be made during Earth Radiation Budget\nSatellite overAflights, and continuous measurements with lower time resolution\nwill be collected to develop a climatology for the site.\nMeasurements of aerosol optical depth with more narrow spectral bands\nARL\nwill begin at Mauna Loa. Newly designed, continuous-output, temperaturetcon-\ntrolled, five-wavelength instruments will be used. Streamlined data process-\ning will be developed to enhance the utility of these new sunphotometers as\ncalibration standards.\nRadiation measurements will be made to determine radiative properties of\narctic haze. Measurements will be made on the ground at Barrow and from air-\ncraft during the Arctic Gas and Aerosol Sampling Program (AGASP) II field pro-\ngram, which was postponed from 1985. Radiation measurements during AGASP II\nwill be used to obtain vertical profiles of optical properties from the air-\ncraft and information on the impact of arctic haze on the surface radiation\nbudget.\n185","GMCC will participate in AGASP II planned for the spring of 1986.\nImportant measurements will include aerosol chemistry profiles, aerosol size\ndistribution in the Aitken size range, and aerosol optical extinction\nprofiles.\nCARBON DIOXIDE\nAccomplishments FY 1985\nThe concentration of atmospheric CO 2 was measured continuously at Barrow,\nMauna Loa, Samoa, and the South Pole. It was found that the annual increase\nin 1984 of the mean annual CO2 concentration has returned to its average value\nsince 1976, 1.5 parts per million (ppm) yr-1 , after the El Niño disturbance of\n1982-1983.\nIn support of the continuous and flask analysis programs, 214 CO, in-air\nreference gas calibrations were made. All calibrations are with respect to\nthe GMCC secondary standards, which were re-analyzed this year at the Scripps\nInstitution of Oceanography (SIO).\nFour thousand flask samples from the flask network were analyzed for CO2.\nThree new sites were added: Shemya Island, Alaska; Alert in the Northwest\nTerritories, Canada; and Midway Island. The 1983 flask data were reprocessed\nto take into account drifts in the concentrations of the flask analysis ref-\nerence gases and analyzer nonlinearity. The flask data also show the recovery\nfrom the 1982-1983 El Niño event as the equatorial bump in the north-south\nconcentration profile regained its \"normal\" amplitude. The mean annual CO 2 2\ngrowth rate recorded in the flask data agreed closely with the continuous\nanalyzers.\nAt Mauna Loa, measurements of CO 2 and CH4 were performed by gas\nchromatography. The CO2 data were compared with data from the nondispersive\ninfrared analyzer. The comparison showed an offset between the instruments of\nabout 0.1 ppm with a one sigma scatter for individual comparisons of 0.14 ppm.\nThe offset may be due to drifts in the reference gases. The CH4 data with a\ndensity of six values per hour were compared with flask data having a density\nof only one value per week. The \"continuous\" CH4 data clearly exhibit struc~\nture on a time scale of days and weeks, presumably reflecting the effects of\ntransport and the action of sources and sinks that show up only as \"noise\" in\nthe flask data.\nShipboard measurements were made of atmospheric CO 2 and CH4 concentra-\ntions and pCO2 and in ocean surface waters. Data from the R/V Knorr and\nthe R/V Discoverer generally support the representativeness of the flask\nnetwork.\nA manuscript was prepared describing a two-dimensional carbon cycle model\nthat successfully describes seasonal variations in total CO2 2 and its 13 12 C\nratio. The model incorporates a two-layer ocean and a new treatment of carbon\nfluxes between the atmosphere and biosphere.\n186","An international intercomparison of CO2 measurements by several labora-\ntories, initiated by GMCC under the sponsorship of WMO, was started. Three\ntanks filled with in-air standards are being circulated among participat-\ning laboratories for analysis.\nThe record of the annual average CO 2 concentrations at Mauna Loa was ex-\namined for compatibility with large net annual emissions from sources other\nthan fossil fuel. It was concluded that only small constant amounts of addi-\ntional carbon, less than 10% of the current fossil fuel release, would be com-\npatible with the record. If, instead, the release of additional carbon has\nincreased annually at the same rate as fossil fuel emissions, i.e., approxi-\nmately doubling over the last 25 years, such a release history could be com-\npatible with observations. The larger the total amount of additional carbon,\nhowever, the more closely the release record has to have matched the fossil\nfuel record. It seems improbable that amounts of additional carbon large\nrelative to fossil fuel emissions have been released since 1958 when the\nrecord began.\nA study was initiated of the relationships between the sea surface temper-\nature (SST) of the eastern tropical Pacific and seasonHto-season changes in\nCO 2 at the four baseline observatories. Preliminary results indicate that\nwarmer# and coldernthan-average SSTs precede above or below-average season-to-\nseason CO 2 changes by about one season at Mauna Loa and two seasons at the\nSouth Pole. Greater lags are indicated for Samoa (where the annual cycle is\nvery complicated) and Barrow. Changes with time in both the magnitude of the\ncorrelation and the lag were found. Correlations are higher when El Niños are\nfrequent. Also there appear to be preferred seasons for effects to show. The\nchanges from fall to spring at Mauna Loa are better correlated with antecedent\nSST than are the changes from spring to fall.\nPlans FY 1986\nContinuous monitoring of the atmospheric CO2 concentration at Barrow,\nMauna Loa, Samoa, and the South Pole will continue. After receipt of the\nresults of SIO calibrations that tie our secondary standards to the most\nrecent manometric values, the continuous data for 1983 and 1984 will be cor-\nrected for reference gas drift and archived with WMO.\nAir samples for CO2 analysis will be collected from the 26 sites of the\nCO2 flask sampling network. The 1983 and 1984 flask data, after correction\nARL\nfor reference gas drifts, will be archived with the DOE/Carbon Dioxide Informa-\ntion Center and WMO. The representativeness of the flask network will be\nevaluated using flask sample data obtained on several cruises from 1982 to\n1985. A report will describe in detail the local geography and conditions at\nthe flask sampling sites.\nThe comparison of the NOAA and SIO records at Mauna Loa for 1973-1984\nwill continue. A detailed comparison will be made of the flask data and the\ndata from the four continuous-monitoring stations for 1983.\n187","The comparative performance of the gas chromatograph and the infrared\nanalyzer at Mauna Loa will be analyzed in more detail. A gas chromatograph\nwill measure atmospheric CO 2, CH4, pCO2, and in ocean surface waters. In\naddition, flask samples will be taken on the ships.\nA laser Raman scattering apparatus for measuring small variations in the\natmospheric oxygen concentrations, which was recently transferred from the\nLawrence Berkeley National Laboratory, will be set up and calibrated.\nThe relationships between SST and CO 2 changes will be explored further,\nparticularly with attention to the lags among the stations and any changes of\nseasonal amplitude.\nDATA ACQUISITION AND METEOROLOGICAL SUPPORT\nAccomplishments FY 1985\nGMCC staff completed the testing and installation of the Control and\nMonitoring Systems (CAMS) at the four GMCC observatories. CAMS controls the\norderly conduct of calibration, scales and displays the data, and records the\nresults. Complete data printout is provided. CAMS is a distributed system in\nthat separate units are supplied to different measurement projects. In this\nway data quality is improved by avoiding long wire runs and potentially noisy\nground loops. CAMS replaced the Instrumental Control and Data Acquisition\nSystem, a central computermcontrolled recording system, in use at the GMCC\nobservatories since 1974.\nThe anemometers and barometers at the four GMCC observatories were recali-\nbrated. Wind and pressure measurements made over the previous 6 years were\nadjusted to reflect the changes in calibration. These variables, along with\nthe temperature and dew point, were tested against physical and statistical\nlimits to isolate questionable data. Once removed, the hourly average values\nfor the past 8 years for each station were printed and converted to microfiche.\nFuture distribution will be by computer-produced magnetic tape or microfiche.\nDuring the past 5 years, the GMCC staff have developed a kinematic trans-\nport model to allow the computation of back trajectories from sampling loca-\ntion, to study the influence of various source regions. The most widely used\nmodel estimates the back trajectory along the standard isobaric surfaces for a\nperiod of 10 days. It has been used to identify the loess plateau and Gobi\ndesert of Asia as a source of dust events at Mauna Loa Observatory in the\nspring. Back trajectories have been used to identify source region's\ninfluence on precipitation chemistry background+monitoring sites. In this\nreporting period GMCC produced approximately 24 station-years of trajectories.\nIn most cases, back trajectories are produced at three standard pressure\nlevels beginning at 0000 and 1200 GMT. More recently, kinematic methods have\nbeen used to track the modeled airflow back along isentropic surfaces.\nIsentropic back trajectories have been limited to case studies of specific\nsituations, owing to the additional cost of computation. Most recently,\nisentropic back trajectories were used to depict the flow to Barrow during the\nAGASP experiment.\n188","Plans FY 1986\nIn addition to the measurement of wind, pressure, temperature, and\nhumidity, continuous monitoring of precipitation amount is to be added.\nHourly average values of precipitation amount will be added to the data base\nat the three northernmost GMCC observatories. Furthermore, with the addition\nof a temperature gradient measurement at Barrow, Mauna Loa, and South Pole in\n1985, it is now possible to compute the bulk Richardson number as an indica-\ntion of local boundary layer stability. Such computations will begin this\nyear.\nGMCC staff plan to participate in the analysis of the flow conditions\nduring the AGASP II study scheduled for March 1986. Isobaric and isentropic\nback trajectories will be used in this analysis.\nA stair-access sampling tower, 128 ft high, is scheduled to be cons-\ntructed at Mauna Loa Observatory. It will allow a much wider variety of\nsampling.\nTRACE GASES\nAccomplishments FY 1985\nAtmospheric baseline measurements of chlorofluorocarbons (CC1,F and\nCC12F2) and N20 were continued at Point Barrow, Niwot Ridge, Mauna Loa, and\nTutuila Island, American Samoa. The measurement method entails collection of\npair air samples at each station at weekly intervals, and subsequent analysis\nof the samples in Boulder with an electron capture gas chromatograph. Bi-\nweekly measurements were made at South Pole during FY 1985 with a gas\nchromatograph.\nTo upgrade measurements of the radiatively important trace gas species\n(RITS) at the GMCC baseline stations, automated gas chromatographs and data\nprocessing equipment were purchased for in situ measurements of CC1 3 F, CC12F2,\nCC14, CH3CC13, and N 0. Work also started on a gas calibration facility for\nthe RITS program.\nMonthly stratospheric balloon-borne water vapor soundings were made in\nARL\nBoulder using frost-point hygrometers. Soundings were obtained also in\nWyoming and Alaska as part of the data validation program of the SAGE II\nsatellite measurement system.\nSurface ozone measurements at the four GMCC baseline stations continued.\nAnalysis of the data from the earlyntormid-1970s through 1984 indicated signif-\nicant positive long-term increases in surface ozone at Barrow and at Mauna Loa\nObservatory. Whereas at Barrow the increase occurred primarily during summer\nmonths, the positive growth rate at Mauna Loa was strongest in winter and, to\nlesser extent, in spring. In the Southern Hemisphere, at Samoa and South\na\n189","Pole, the secular trends in surface ozone were negative, but not statistically\nsignificant on an annual basis. They were, however, statistically significant\nat these two stations during summer months.\nMeasurement of atmospheric methane in air samples collected from the CO 2\nnetwork continued. This is a cooperative program involving GMCC, the Common~\nwealth Scientific and Industrial Research Organization (CSIRO) in Australia,\nand the Oregon Graduate Center. Data for the first 2 years are complete. The\nglobal distribution of methane as a function of time in 1983 and 1984 was docu-\nmented. The data processing equipment was upgraded and a gas chromatograph\nacquired for continuous use at Barrow. The data show a smooth seasonal cycle,\nalmost a sine wave, through the Southern Hemisphere, which is superimposed on\nsteady increase of about 1% per year. The seasonal cycle at the Northern\na\nHemisphere sites is more complex and differs in phase and amplitude from the\nSouthern Hemisphere cycle, but the overall growth rate is the same for both\nhemispheres. There is a large North-South gradient in the concentration,\nabout 8%\nOne-liter flasks for methane were collected daily at Miami, Fla.\nPlans FY 1986\nAtmospheric baseline measurement of the chlorofluorocarbons and N20 will\nbe continued at the GMCC observatories and at Niwot Ridge, Colo. Testing of\nthe automated gas chromatographs will continue, and several of the instruments\nare expected to be deployed to the field stations. A calibration facility for\nthe RITS program will be established, and several sets of calibration gases\nwill be prepared for use at the field station.\nMonthly stratospheric water vapor soundings in Boulder will be continued.\nSpecial ozone and water vapor soundings will be made with balloon=borne instru-\nmentation to validate the Stratospheric Aerosol and Gas Experiment (SAGE II)\ndata. Laboratory work, previously delayed, will be performed in order to\ndetermine the reason for the measurement offset of the GMCC frost-point hygro-\nmeter sonde and the Aeronomy Laboratory's Lyman-alpha water vapor instrument.\nContinuous monitoring of near-surface ozone will continue at the four\nGMCC baseline observatories. The feasibility of establishing an ECC ozone-\nsonde network for long-term tropospheric ozone measurements will be\ninvestigated.\nThe measurement of CH4 in flask air samples from the network by gas chrom-\natography will continue. In situ gas chromatographs will be installed at\nBarrow and Mauna Loa. We will determine the feasibility of obtaining a CO\ndetermination on the same chromatogram with CH4. Interaction will be started\nwith the Global Atmospheric Gas Experiment (GAGE) to improve gas standards and\ndata compatibility.\n190","TEMPERATURE\nAccomplishments FY 1985\nGlobal tropospheric and stratospheric temperatures obtained from a\n63-station radiosonde network were updated through the spring of 1985.\nNorthern Hemisphere surface temperatures were indicated to be 0.2°C above\naverage and 850m300 mb temperatures 0.1°C below average in 1984, compared with\n0.5°C and 0.4°C above average, respectively, in 1983. Temperatures in the\n300H100 mb layer bracketing the tropopause were 0.6°C below average in 1984\n(compared with 0.3°C below average in 1983), and in the 100-30 mb layer of the\nlow stratosphere 0.4°C below average (the same as in 1983). At both the surm\nface and in the 850-300 mb layer, Northern Hemisphere temperatures were indin\ncated to be 0.140.3°C below average also in the winter and spring of 1985.\nBinomial smoothing of these seasonal temperature deviations shows Northern\nHemisphere surface and tropospheric temperatures in late 1984 and early 1985\nto be the lowest since 1976. It remains to be determined whether this cool-\nness is a longdelayed memorial to the El Chichon volcanic eruption in the\nspring of 1982 (delayed because of the atmospheric warming induced by the\npowerful El Niño of 1982-83).\nPlans FY 1986\nTropospheric and stratospheric temperature data throughout the world will\ncontinue to be updated, with emphasis on the geographical extent and duration\nof the recent cooling.\nHUMIDITY\nAccomplishments FY 1985\nAs a preliminary step in determining if there have been detectable tropor\nspheric humidity trends on a hemispheric and global scale, a study of humidity\nvariations at Brownsville, Tex., and Great Falls, Mont., for a 23-year intere\nval was completed. It is apparent that great care must be taken with regard\nARL\nto changes in instrumentation and measurement technique, and that for proper\nresults the humidity should be evaluated at significant points as well as at\nmandatory pressure surfaces. A computer program was completed that can ex-\ntract humidity data from individual soundings at the 63 stations, flag anoma-\nlous data, and determine monthly means.\nPlans FY 1986\nAfter some examination of the computer output to ensure that reliable and\nrepresentative humidity values are being obtained, relative humidity, mixing\n191","ratio, and precipitable water will be monitored at the same 63 radiosonde sta-\ntions used for temperature monitoring.\nSUNSHINE DURATION AND CLOUDINESS\nAccomplishments FY 1985\nSunshine duration and cloudiness data for the contiguous United States\nwere analyzed through the summer of 1983, and the data are now being updated\nthrough 1984. There has been a significant tendency for United States cloud-\niness to be above average, and sunshine duration below average, following El\nNiño occurrences, but data for the summer of 1983 indicate that cloudiness and\nsunshine duration had already returned to average with the decline of sea-sur-\nface temperatures in eastern equatorial Pacific. Since 1950 there has also\nbeen a significant general trend of increasing cloudiness and decreasing\nsunshine.\nPlans FY 1986\nSunshine duration and cloudiness data for the United States will continue\nto be updated to see if the tendency for a long-term increase in cloudiness,\nand decrease in sunshine duration, continues over the United States.\n192","Eldon E. Ferguson\nAERONOMYLABORATORY\nDirector\nBoulder, Colorado\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nSEL\nNSSL\nWPL\nARL\nAL\nAOML\nPMEL\nGLERL\nGFDL\nThe Aeronomy Laboratory (AL) conducts research on chemical and physical\nprocesses of the Earth's atmosphere to advance the capability to monitor, pre-\ndict, and control the quality of the atmosphere. The research concentrates on\nthe stratosphere and troposphere but also involves the ionosphere.\nResearch methods involve both in-situ and remote measurement of critical\natmospheric parameters, including chemical composition and dynamic properties\nsuch as wind velocities, turbulence, and wave motions. Theoretical programs\nin atmospheric photochemical modeling and in atmospheric dynamics and trans-\nport support the observation programs. An experimental laboratory chemical\nkinetics program supports the theoretical photochemical modeling program and\nalso supplies input for the development of new atmospheric monitoring and\nmeasurement technology.\nThe research of the Laboratory is accomplished by seven interactive pro-\ngrams: Atmospheric Chemical Kinetics, Atmospheric Dynamics, Atmospheric Samp-\nling, Atmospheric Wave and Turbulence Theory, Optical Aeronomy, Theoretical\nAeronomy, and Tropical Dynamics and Climate.\nAL\nThe major focuses of research are Air Quality and Climate.\nATMOSPHERIC SAMPLING\nThe origins of the present Atmospheric Sampling program lie in the recog-\nnition that human activities may inadvertently pose a threat to the Earth's\nstratospheric ozone layer, which serves as a shield against harmful solar ra-\ndiation. The Atmospheric Sampling Group was formed to address this critical\nproblem. The group's research efforts led to the first successful measure-\nments of chlorofluoromethanes at the altitudes in the stratosphere where these\n193","compounds are significantly photodissociated into reactive chlorine species.\nThe findings supported the predictions from theoretical models concerning the\nphotochemistry of these compounds and, hence, the predictions of the potential\nadverse consequences to stratospheric ozone. Since that time, the scientific\nefforts of the group have followed the approach used in these stratospheric\nchlorofluoromethane measurements. That is, problems are selected that combine\nsignificant new scientific research with national or global atmospheric ques-\ntions of environmental import. The instruments and techniques required in the\nstudies are generally conceived, designed, and developed within the group and\nare subjected to rigorous laboratory and field validations. The subsequent\nfield application of these instruments and techniques employs a variety of\nplatforms: balloons, stratospheric and tropospheric aircraft, ships, vans, and\nsemipermanent ground stations.\nThe experience, skills, and interests of the group have expanded consid-\nerably since the initial stratospheric chlorofluoromethane studies and now en-\ncompass a broad range of topics in atmospheric chemistry and dynamics, which\ninclude the following:\nThe natural emissions that contribute to atmospheric acidity and\nalkalinity.\nThe transport, transformation, and deposition processes involved in\nacid deposition.\nThe tropospheric/stratospheric exchange processes that are factors\nin regulating stratospheric and tropospheric chemistry and climate.\nThe tropospheric and stratospheric photochemical cycles responsible\nfor the production and destruction of global ozone.\nRelative to potential inadvertent deleterious alterations of the Earth's at-\nmosphere, several key environmental issues are being addressed: stratospheric\nozone depletion, acid deposition, tropospheric ozone production, and climate\nalteration.\nAccomplishments FY 1985\nDuring the summer of 1984, an intensive study of atmospheric reactive\nnitrogen chemistry was carried out at the Aeronomy Laboratory's Niwot Ridge\nresearch site in the Colorado mountains west of the Denver metropolitan area\nand near the Continental Divide. The summer period was chosen for this ini-\ntial study because the elevated temperatures, solar intensity, and humidity\nenhance the photochemical processes under study. However, for a complete\npicture of the reactive nitrogen chemistry, the wintertime contrast is partic-\nularly valuable. This was studied during the following fall and winter.\nBoth summer and winter studies focused on the following nitrogen species:\nnitric oxide (NO), nitrogen dioxide (NO), peroxyacetyl nitrate (PAN), nitric\nacid (HNO3), and particulate nitrate (NO3). In addition, the sum of the\nreactive nitrogen species (NOy) was addressed by a newly developed technique.\nThe atmospheric concentrations of NO y and the individual reactive nitrogen\n194","species were measured with instruments developed by the Aeronomy Laboratory,\nexcept for PAN, which was examined by SRI International and the National\nCenter for Atmospheric Research.\nIn the summer measurement campaign, it was found that the sum of the\nconcentrations of the individually measured species (NO + NO + PAN + HNO 3\n+\nNO) was typically only 55% of the total reactive nitrogen (NO y ) measure-\nments. In the winter, it was observed that this sum was nearly equal to the\ntotal. This implies that, in the summer, the higher level of photochemical\nactivity promotes the formation of another unidentified reactive nitrogen\nspecies. Organic nitrate species other than PAN are candidates. These stud-\nies point out that previous inventories of reactive nitrogen species have been\nincomplete by typically one-half.\nIn addition, these contrasting summer-winter studies have revealed new\nimportant seasonal variations among the well-known reactive nitrogen species.\nThe summertime measurements had demonstrated that PAN concentrations were\noften as high as those of NO and NO These results illuminated the signifi-\ncant role that PAN plays in the nitrogen photochemistry of non-urban areas.\nDuring the wintertime measurement period, the PAN levels were in excess of\nfour times those of NO and NO, 2, which underscored this role of PAN and, since\nthe air masses that were sampled were often quite clean, pointed out the sig-\nnificance of PAN as a reservoir of reactive nitrogen during long-range trans-\nport.\nFollowing these summer and winter measurements at Niwot Ridge in 1984,\nthe ensemble of instruments was fitted into a van and used to explore tropo-\nspheric nitrogen chemistry at a new location on the west coast at Point Arena,\nCalif. This measurement series provided the opportunity to test models of the\nchemistry of maritime air, a system in which only a few fundamental processes\nare thought to be dominant.\nPoint Arena is located on the Pacific coast about 175 km north of San\nFrancisco. This site receives inflow of marine air from the Pacific Ocean.\nBetween 24 April and 4 May 1985, NO, NO, HNO 3, particulate nitrate, NO\nNOy, PAN, ozone (03) and meteorological parameters were measured. During\nthis\nperiod, local conditions were dominated by moderately strong, northerly winds\nwith some westerly component. Episodes of air containing quite low levels of\nthe odd-nitrogen species were observed. During the measurement period, NO\nlevels ranged from ~30 pptv to >1000 pptv, reflecting the origin and histor-\nies of the air masses that were being sampled. The systematic trends and the\nintercorrelations of the species' concentrations in marine air, as well as the\nAL\ncorrelation of the 03 and odd-nitrogen concentrations with air parcel trajec-\ntory origin, are being compared with models of the expected chemistry.\nAt Point Arena, measurements were also made of ammonia (NH 3), which is an\nimportant trace constituent in the atmosphere because of its alkalinity and\nits homogeneous chemistry. The measurements were made using the tungsten OX-\nide denuder tube method. NH 3 mixing ratios ranged from 140 pptv to 1.1 ppbv,\nwith a mean of 325 pptv. Surface wind directions were virtually always be-\ntween southwest and northwest (i.e., from out over the ocean), indicating that\nthe coastal or oceanic regions are probably a source of NH\n195","Formate and acetate, as well as other organic and inorganic anions, were\nmeasured in precipitation collected at Niwot Ridge (a remote site), Boulder\n(an urban site), and Mauna Loa, Hawaii (a remote oceanic site). The organic\nanion concentration is usually at least 20% of the nitrate concentration and\noccasionally is equal to the nitrate. Formate is the dominant organic anion\nmeasured; concentrations as large as 9 X 10~5 M occur in summer rain showers.\nVarious dicarboxylic anions are also observed, but their concentrations are\ngenerally much lower than that of formate. Although the total ion concentra-\ntion is usually less at Niwot Ridge than at Boulder, ionic balance often leads\nto a somewhat lower pH at Niwot Ridge. Diethylamine has also been detected in\ntropospheric aerosols collected at Mauna Loa and Niwot Ridge. The amine con-\ncentration was, at times, a substantial fraction of the ammonium (NH4+) con-\ncentration, making it potentially an important basic material in aerosols.\nConcentrations as large as 200 pptv were observed. A large diurnal variation\nwas observed at both sites, the maximum occurring in late afternoon at Mauna\nLoa but near noon at Niwot. The present observations show that these species\ncan be significant contributors to the acidity in urban and rural continental\nareas.\nSulfur compounds also have an important role in the acidification of\nrainfall. An assessment of the significance of natural biogenic sulfur sour-\nces compared with anthropogenic sources requires the measurement of fluxes at\nor below 10 g S m-2 min- over large geographic areas. To date, such an\nassessment has rested almost entirely on one study completed in 1979. In view\nof the importance attached to these measurements, the analytical difficulties\nrecognized by those investigators, and recent improvements and advances in\nmeasurement techniques for trace sulfur species, a reassessment of the\nstrengths of natural sulfur fluxes was deemed desirable. As part of this,\nsimultaneous measurements at three previous measurement sites were undertaken\njointly by NOAA, Washington State University Air Resources Laboratory, and\nUniversity of Idaho Department of Chemistry in July and August 1985. The re-\nsults for the magnitude, temperature dependence, and temporal variation of the\nflux of hydrogen sulfide (H2S), carbonyl sulfide (COS), carbon disulfide\n(CS2), dimethyl sulfide CH3SCH3), and dimethyl disulfide (CH3S2CH3) at these\nthree diverse sites will provide crucial information for assessment of the\nearlier studies, as well as contribute significantly to an inventory of natu-\nral sulfur emissions.\nRegarding natural nitrogen emissions, it is currently believed that the\nemission of NO, from soils represents one of the major natural sources of the\nnitrogen oxides. Several techniques are being used to measure these fluxes,\nprincipally enclosure, gradient, and eddy correlation methods. The enclosure\ntechniques usually measure the NO. flux from a small, enclosed sample of soil\n(typically ~1 square meter); the gradient and eddy correlation methods deter-\nmine the average NO fluxes from larger areas (typically thousands of square\nmeters). The present study is aimed at intercomparing the results obtained\nusing the enclosure and gradient methods to determine NO fluxes from the soil\nduring the nighttime hours. These measurements were carried out on grassland\nat a Boulder, Colo., site during August and September 1985. The NO fluxes\nduring this period of intercomparison ranged from 0.3 ng N m-2 Sn't to 40 ng N\nm ² s-1. There was general agreement in the results from both techniques over\nthis range, lending a large measure of confidence to these methods.\n196","Flights on NASA's ER-2 aircraft were conducted for the new instruments\nthat will take part in the Stratospheric Tropospheric Exchange Program. These\nflights tested the Laboratory's instruments for measuring water vapor, total\nwater (water vapor and ice), and 03, species that are tropospheric and strato-\nspheric tracers. Furthermore, the flights tested the inertial-separator/inlet\nsystem, which is designed to separate ice from water vapor, both of which will\nbe measured individually.\nPlans FY 1986\nField studies of nitrogen chemistry, such as those that were conducted at\nNiwot Ridge and Point Arena, will be continued in the summer of 1986 in con-\njunction with flux measurements of nitrogen species from soils. Studies will\ntake place at a variety or sites differing in soil type and vegetation. This\nwill constitute the first examination of nitrogen emissions from continental\nU.S. soils. NH 3 will also be measured.\nThe NO technique will be added to the airborne NO and NO 2 instruments\nfor use in collaboration with the National Center for Atmospheric Research,\non\na series of aircraft flights in the summer of 1986. NASA's aircraft will\ncarry a suite of instruments that will focus on the reactive nitrogen chemisH\ntry of the troposphere, including species distributions, reactions, and in-\nstrument reliability.\nA diode-array spectrometer will be used to establish the temperature\ndependence of the absorption cross section of nitrogen trioxide (NO 3 )\nThe\natmospheric concentrations of NO 3 are most often deduced using the cross sec-\ntion in the 662-nm region, where it has been assumed that the cross section\nhas no temperature dependence. However, recent preliminary observations have\nsuggested that this assumption may not be correct and hence the need for this\nre-investigation.\nA differential absorption lidar technique will be developed as a means of\nmeasuring 0 3 in the free troposphere. There is currently no fully acceptable\nmethod to do this, despite the need to assess potential human alteration of\nthis climatically important chemical species. This instrument will be located\nat Fritz Peak. The goal is continuous measurements of the 03 profile up to\n15 km. The observed variance of the 0 3 at each altitude will be used to test\npredictions that have been made by the Geophysical Fluid Dynamics Laboratory's\ngeneral circulation model.\nAL\nThe stratospheric/tropospheric exchange instrument package will be aug-\nmented by an NO instrument, which will provide measurements of this strato-\nspheric tracer at ER-2 aircraft altitudes (21 km). The first experiment will\naddress small scale exchange processes in the vicinity of jet streams. It is\nplanned to concentrate on the lower side of the jet stream where flow of tro-\npospheric mass into the stratosphere has been postulated to occur.\n197","OPTICAL AERONOMY\nThe Optical Aeronomy program uses optical measurements of the atmosphere\nas a tool for studying fundamental atmospheric processes such as energy bal-\nance, composition, and dynamics. Major attention is being given to measure-\nments bearing on the composition and dynamics of the lower atmosphere, princi-\npally the troposphere and stratosphere. Important problems in the upper at-\nmosphere continue to receive attention.\nAccomplishments FY 1985\nThe total column abundance of NO 3 in the stratosphere at night has been\nmeasured by the Optical Aeronomy group for five years at 40°N; additional ob-\nservations have been obtained at 19°N, °N, 51 °N, and 64°N. At low latitude\nthe mean abundance is about 8 X 1013 cm-2; it varies little with season and\nappears to be in general agreement with a model based upon simple NOX chemis-\ntry except, perhaps, in the spring. At middle latitudes the variation in\nabun- dance exceeds prediction and the abundance exhibits a close relation to\nthe highest latitude experienced by stratospheric air prior to its arrival at\nmiddle latitudes; the higher the latitude the lower the NO 3 abundance. At\n64°N the upper limit in April and November is 1.5 X 10 13 cm-2; in April this\nis far below what is predicted by models. From these observations we inferred\nthat a scavenger of NO 3 is continually produced in the stratosphere at high\nlatitude and that when there is strong equatorward flow the scavenger can at\nleast reach middle latitudes. The identity of the scavenger remains a mystery\nas does the importance of its role as a sink for NOX in the stratosphere.\nThe new diode array spectrograph has been in extensive use for studies of\ndaytime stratospheric NO 2 and 03. Data analysis is currently under way. The\nprevious sunrise/sunset limits are now removed and full-day measurements are\nin progress.\nInterpretation of the measurements of the effects of the El Chichon dust\ncloud on NO 2 continued. Large reductions in NO 2 column were observed whenever\nthe volcanic dust cloud appeared near the latitude of Fritz Peak. Similar re-\nductions were noted from observations of NO as far south as Socorro, New\nMexico. Heterogeneous surface reactions with the cloud parti- cles are\ncertainly involved in this poorly understood phenomenon.\nWork on NO 2 with the Solar Mesosphere Explorer satellite team at the Uni-\nversity of Colorado continued. With the completion of the major stratospheric\nstudy of NO , work concentrated on interpretation of nadir measurements. This\nincluded work on the detection of NO 2 in the troposphere produced by both\nlightning and human activity. Clear signatures were found in NO2 abundance\ndue to lightning in the tropical ocean regions, and cities under the satellite\ntrack show up as sources of significant NO 2 due to pollution.\nAn automatic instrument collected data on high-altitude OH (80 km), ther-\nmospheric 0+ (300-450 km), and high-altitude O2. Extensive data analysis and\ninterpretation is under way.\n198","Measurements of stratospheric OH continued at Fritz Peak. This unique\nseries of measurements has produced a consistent seasonal and annual picture\nof OH. In particular, a large-amplitude oscillation in vertical column abun-\ndance was detected during a solar eclipse. This is the first observation of a\nringing response of any atmospheric constituent to an eclipse. The physical\nmechanism for this ringing in column abundance is not understood.\nDetailed analysis of the operating characteristics of Fabry-Perot spec-\ntrometers continued. Measurements of ionospheric and thermospheric winds\ncontinued, using the Fabry-Perot instrumentation at Fritz Peak.\nPlans FY 1986\nWe shall begin development of a laser system coupled to a new high-reso-\nlution spectrograph to measure tropospheric OH by long-path absorption. Few\nexperimental data exist on this critical species. In addition, we will devel-\nop an efficient retroreflector for use in the measurements, which will elimin~\nate many problems with long-path intensity calibrations.\nEfforts will continue in collaboration with the Naval Research Laboratory\nfor development of a high-resolution ultraviolet shuttle spectrograph for\nmeasuring upper stratospheric and mesospheric OH and thermospheric NO on a\nglobal basis. Flight is expected by 1989.\nRenewed efforts will be made to study stratospheric NO , NO 3 and the NO 3\nscavenger with improved instrumentation and detectors. NO 3 will be studied in\ndetail in the troposphere by long-path absorption at Fritz Peak.\nThe study of dynamics of NO from SME satellite data will continue.\nThe long-term column determinations of stratospheric OH will continue.\nNew instrumentation will be developed for determining the tropospheric\nand stratospheric radiation fields. Theory has conclusively demonstrated the\nimportance of radiative multiple scattering and ground albedo in the photo-\nchemistry of the atmosphere. Essentially no actual measurements exist. The\nLaboratory can make a unique contribution in measurement of this radiation\nfield first from Fritz Peak and later from a U-2 aircraft.\nDevelopment of a high-resolution spectrograph for measuring tropo-\nAL\nspheric trace species will begin.\nMeasurements of mesospheric and thermospheric wind systems will continue.\nTHEORETICAL AERONOMY\nThe objective of the Theoretical Aeronomy Program is to undertake theo-\nretical studies of important atmospheric problems, to construct and utilize\ncomputer models of the chemistry and dynamics of the atmosphere, and to ana-\nlyze atmospheric data collected within the Laboratory or by collaborative\n199","experiments. The ultimate goal of the program is to attain an understanding\nof the composition, dynamics, and energy budget of the atmosphere that is\nsufficiently detailed to permit accurate predictions of trends. In recent\nyears the principal concern has been with problems related to the minor-con-\nstituent composition of the stratosphere and mesosphere (the middle atmos-\nphere), deriving largely from the widespread practical concern with stratos-\npheric ozone and its potential depletion by artificial pollutants. More\nrecently, however, the activities of the group have expanded to investigate\nproblems of tropospheric chemistry and tropical atmospheric dynamics. In\naddition, the biosphere-atmosphere interaction is an important new research\narea. These new areas are expected to grow, in parallel with corresponding\ngrowth and shifts of emphasis in the experimental programs of the Laboratory.\nMost of the program's projects are developed and carried out in close collab\noration with the Laboratory's experimental programs, or with other atmospheric\nresearch groups outside the Laboratory, including at present those at GFDL,\nNCAR, and the University of Colorado. These outside links are essential to\nthe objectives of the program, and will be maintained and strengthened where\npossible in future years.\nIn addition to its own projects, the group has the important function of\nassisting other Laboratory programs on problems that require advanced computer\nprogramming techniques. This direct service function provides further coup-\nling between this program and the more experimental side of the Laboratory.\nAccomplishments FY 1985\nTROPOSPHERE\nResearch in tropospheric photochemistry centers around acid deposition\nand tropospheric ozone. Acid deposition is a serious problem in the north-\neastern United States and eastern Canada. Precipitation with pH in the range\nof 4.0 to 4.5 is quite common in these areas downwind of midwestern industry.\nMost of the anions contributing to the high acidity are SOH and NO the\nprecursors of which are SO2 and NO (NO + NO2). Tropospheric ozone has a\ncentral role in the photochemistry that controls the abundance and interaction\nof SO2 NO. X , and other important atmospheric trace gases (e.g., CO, CH4, and\nH2S). The photochemistry and transport of acid material and ozone are closely\nrelated. There is increasing evidence that tropospheric ozone may have been\nperturbed by anthropogenic emissions of hydrocarbons and NO, (NO + NO Perm\nturbation of tropospheric ozone may cause a chain reaction that could change\nthe distribution of trace gases. Since ozone and some of the trace gases\nabsorb infrared radiation in the window of CO2 and H2O absorption, the radi-\nation budget in the troposphere, and thus the climate, may be altered. In\naddition, surface ozone may damage plants and may be a health hazard.\nThe Theoretical Aeronomy Program is involved in several topics of re-\nsearch in the areas of tropospheric ozone and acid deposition:\nDevelopment of a fine-resolution planetary boundary layer model to\nsimulate the transport and photochemistry of 03, NOX, and hydrocarbons,\nespecially in the surface layer.\n200","Collaboration with the Atmospheric Sampling Program on planning and\ninterpreting measurements of NOX, 03, HNO 3 , SO2 and particulate NO 3 and\nSO, with emphasis on measurements made at Niwot Ridge, Colorado.\nCollaboration with scientists at GFDL on modeling the tropospheric ozone\nand NOX distributions with a three-dimensional general circulation model.\nCollaboration with scientists at NCAR on developing a mesoscale air quali\nity model for the Colorado Front Range.\nDevelopment of a combined liquid-phase and gas-phase photochemical model\nto study oxidation of NO, and SO2.\nModel studies of the distribution of NO and SO2 that are produced from\nnatural sources.\nThe fine-resolution planetary boundary layer model was used to evaluate\nthe distribution and the photochemistry of naturally emitted hydrocarbons\n(isoprene and monoterpenes). Several important findings resulted from this\nstudy. It was found that natural hydrocarbons at typical observed values\naffect the ambient photochemistry significantly. The peroxyl radicals (HO 2 +\nRO2) increased by more than a factor of 2. On the other hand, the OH radical\nis reduced by about 50% when natural hydrocarbons are included. Furthermore,\nthe model predicts that isoprene and monoterpene mixing ratios decrease quick-\nly with height in the surface layer. This is the result of the short chemical\nlifetime of these natural hydrocarbons and the highly stable condition in the\nsurface layer.\nBecause of the high concentration of natural hydrocarbons in the surface\nlayer, RO 2 2 and HO 2 may be high enough to account for the missing oxidant ob-\nserved at Niwot Ridge. In turn, the 03 formation rate in the surface layer\nwill be increased proportionally. However, because of the long lifetime of 0 3\nits diurnal behavior is controlled by the photochemistry in the entire plane-\ntary boundary layer where the concentrations of natural hydrocarbon are much\nlower. It shows that measurements made near the surface need to be intern\npreted carefully.\nThe summer 03 production efficiency per unit NOX at Niwot Ridge was\ncompared with production efficiency at eight other rural stations in the\ncentral and eastern United States. With only one exception, the daily 03\nproduction rates for these stations lie within the range of 6 to 12 ppb per\nppb of NOX, a remarkable agreement considering the wide range of geographical\nlocations. Model-calculated efficiency agrees with observed values when NO\nAL\nis greater than 1 ppb. The consistency of the summer O3 production efficiency\nsuggests that the average daily 0 3 production at a rural station may be\npredicted if NOX is known. The dependence of 03 production rate on NOX also\nallows a crude estimate of the total 0 3 production in the summer season for\nanthropogenically emitted NO and non-methane hydrocarbon. For the eastern\nUnited States, we estimate an average summer column 0 3 production of\n6.4 X 1011 cm-2s-1, about 13 times the average cross-tropopause 03 flux.\nSeasonal variation of ozone at Niwot Ridge was found to be a very\nsensitive function of NO At NO level less than 0.2 ppb, the 03 seasonal\nvariation agrees with results from general circulation model calculation that\n201","excludes photochemistry. When NO, is greater than 0.3 ppb, there is a clear\nsummer maximum due to photochemical production of ozone. The difference be-\ntween the 03 concentration for NO less than 0.2 ppb and the average 03 con-\ncentration gives the lower limit estimate of the anthropogenic impact on the\n03 distribution at the site.\nPeroxyacetyl nitrate (PAN) and other organic nitrates were shown to be\nmajor odd-nitrogen species in the rural atmosphere. They may be the major\ncarrier of NOX to the free troposphere and remote areas. In the summer, PAN\ncorrelates with 0 3 and NOX very well in the afternoon. This is consistent\nwith the photochemistry of PAN. The peroxyacetyl radical and the equivalent\nacetaldehyde calculated from the observed PAN level provide valuable infor~\nmation on the total reactive non-methane hydrocarbon abundance at the measure-\nment site. Organic nitrates may contribute substantially to the total odd-\nnitrogen observed at Niwot Ridge.\nThe mesoscale model development progressed as planned. A vertical dif-\nfusion based on Blackadar's scheme is added to the bulk planetary boundary\nlayer. Some modifications to Deardorff's scheme have been made to improve the\nvertical mixing of momentum during calm wind conditions. At the interface be-\ntween coarse-mesh and fine-mesh domains, the smoother-desmoother scheme used\nin the model generates noise near the interface. A new scheme similar to\nNewtonian relaxation was applied to the interface. It has improved the trane\nsition from the coarse-mesh domain to the fine-mesh domain. The predicted\nwind fields of nested grid and uniform grid were compared with observed values.\nIt was concluded that the nested grid with two-way interaction gives the best\nresults.\nMIDDLE ATMOSPHERE\nChemical-dynamical modeling studies of the middle atmosphere continued,\nin collaboration with the National Center for Atmospheric Research. Research\nfocused on possible transport effects on future ozone depletions due to chlo-\nrofluorocarbons, and on a more complete understanding of transport in the\nmesosphere.\nQuantitative estimates of the effects of increasing chlorofluorocarbon\nabundances on stratospheric ozone have largely been performed with one-dimen-\nsional models. Current one-dimensional models predict a rather small steady-\nstate ozone column reduction of about 4-6% These small values result from a\nbalance between large depletions in the upper stratosphere that are compen-\nsated to a substantial degree by increases in the lower stratosphere (the\nchemical \"self-healing\" effect), so that the total ozone column change is a\nsmall difference between the two.\nIt is, however, well established that lower stratospheric ozone is dynam-\nically rather than chemically dominated, particularly at middle and high lati-\ntudes in the winter season, so that one-dimensional models may not be the most\nappropriate tool for evaluation of these effects at those latitudes and sea-\nsons. In particular, the lower stratospheric self-healing effect is likely to\nbe significantly less important at high latitudes than onerdimensional model\nprojections indicate. Our two-dimensional residual Eulerian model calculation\nof the ozone response to projected chlorofluorocarbon increases showed that\n202","the predicted ozone reductions during winter and spring in high latitudes are\nlikely to be substantially greater than one-dimensional model predictions, in\nagreement with some other multi-dimensional model studies. This occurs\nbecause ozone is largely dynamically controlled at these latitudes and sea-\nsons, and because the net transport is downward directed from higher altitudes\nwhere large ozone depletions due to chlorine increases are predicted to occur.\nThe observed spring maximum in the annual cycle of total ozone is a direct re-\nsult of the same downward transport phenomenon, strongly suggesting that a\nmaximum in ozone depletion must be expected to occur during that season as\nwell.\nThe behavior of mesospheric ozone also exhibits important variations that\nare likely to be due to transport processes, and can be used to test our un-\nderstanding of mesospheric dynamics. In particular, ozone observations from\nthe Solar Mesosphere Explorer (SME) satellite exhibit a pronounced equinox\nmaximum at about 80 km which is not explained by photochemical theory. Recent\nwork suggested that breaking small-scale gravity waves play an important role\nin the dynamics of the mesosphere. We incorporated a parameterization of the\npropagation and dissipation of gravity waves into our dynamical chemical model.\nThe parameterization enables us to compute both the momentum forcing and tur-\nbulent diffusion induced by the waves at mesospheric altitudes, providing a\nphysically based description of the variations in transport of photochemical\nconstituents as a function of latitude and season. The seasonal variations in\nthe computed eddy diffusion coefficient are consistent with the large seasonal\nchanges in MST radar echoes at Poker Flat, Alaska, observed by the Aeronomy\nLaboratory's Atmospheric Dynamics group. The computed variations in eddy dif-\nfusion have important effects on the transport of chemical species in the mes-\nosphere, particularly atomic oxygen and water vapor. Changes in water vapor\ndensities near 80 km were shown to induce a seasonal variation in ozone\nclosely resembling that observed by SME. The consistency between the model\nsimulation of both chemical and dynamical observables strongly supports the\nsuggestion that gravity waves play a very important role in determining the\nstructure of the mesosphere and lower thermosphere.\nAnther chemical tracer of interest at mesospheric altitudes is carbon\nmonoxide. Carbon monoxide is produced very rapidly in the lower thermosphere\nthrough photodissociation of carbon dioxide. In the mesosphere, carbon mon-\noxide is destroyed through reaction with OH. Therefore, the vertical profile\nof carbon monoxide generally decreases from the source region at about 100 km\nto the sink region near 50-70 km. The vertical structure depends strongly on\nthe rate of transport between the thermosphere and the mesosphere, and on the\nabundance of mesospheric OH. OH is produced predominantly by water vapor\nphotolysis at altitudes above about 65 km, and it is therefore present in\nAL\nlarger quantities in summer, when the solar zenith angle is smaller, than it\nis in winter. In the polar night region, OH is not produced at all, and the\nlarge CO abundances obtained in the thermosphere may be transported down into\nthe mesosphere without encountering the loss process with OH that exists in\nthe sunlit atmosphere. Therefore, CO represents an excellent tracer for mest\nospheric transport, particularly inside the polar night region. We presented\na twordimensional chemical-dynamical model study of CO to examine this be-\nhavior quantitatively. Comparison with several ground-based microwave obser-\nvations of CO were used to show the utility of CO for tracer studies.\n203","Plans FY 1986\nTROPOSPHERE\nTropospheric ozone and its possible perturbation by anthropogenic activi-\nties will continue to be one of the major subjects of our research. Important\nproblems in this area are the photochemical production and destruction of 03 9\ntransport of 03, the distribution of tropospheric NOX, OH, and RO 2 radicals,\nand the effects of nonmethane hydrocarbons. The role of natural hydrocarbons,\nin particular, will be examined in view of their large emission rate and their\nhigh reactivity toward both 03 and OH radicals. We will continue to study\nthese problems by working closely with the Atmospheric Sampling group and the\nAtmospheric Chemical Kinetics group. Collaboration with scientists at GFDL on\nthreendimensional modeling will continue in both stratospheric and tropospher-\nic modeling.\nExpanded studies of the acid deposition problem will continue with empha-\nsis on atmospheric transformations of SO 2 and NOX, heterogeneous processes,\nand natural emissions of sulfur and nitrogen compounds. Developing a regional\nacid deposition model for the Colorado Front Range is a long-range goal for\nthis group. The model will be very useful for interpreting the data at Niwot\nRidge and for designing other measurement strategies and could be readily ap-\nplied to study regional oxidant problems such as that of rural 03. This model\nis being developed in collaboration with scientists at NCAR.\nThe interaction of the atmosphere and the biosphere is an important and\nfascinating research subject. Biogenic emissions of hydrocarbons, reactive\nnitrogen species, NH3, and reduced sulfur species may have significant impact\non the tropospheric 03 and acid deposition. We plan to evaluate the effect of\nbiogenic emissions of nitrogen oxides and hydrocarbons on the tropospheric\nchemistry.\nMIDDLE ATMOSPHERE\nThe interaction of dynamics and chemistry in the middle atmosphere rep-\nresents an important element in our understanding of aeronomy. Our studies of\nthe natural and perturbed stratosphere and mesosphere will continue. We will\ncouple a detailed treatment of infrared radiation, as well as a linear plane-\ntary wave model, into our chemical/dynamical model. With these tools, the\nzonally averaged radiative/chemical/dynamical behavior of the stratosphere can\nbe investigated, and the role of chemical transport by planetary waves can be\nexamined.\nATMOSPHERIC CHEMICAL KINETICS\nThe primary activity of the Atmospheric Chemical Kinetics program is the\nexperimental investigation of chemical reactions that are important in the at-\nmosphere. Although the research is focused on the effects of man-made chemi-\ncals, a second objective is to understand the natural, unperturbed atmosphere.\nThe information obtained in this program includes the rate coefficients and\n204","mechanisms of chemical reactions, thermochemical and spectroscopic data, and\nvalues of photochemical parameters.\nThe chemistry of the stratosphere is of great interest because of the\npotential for humans to alter the ozone layer inadvertently, with disastrous\nconsequences. First, the possibility of an ozone reduction from exhaust chem-\nicals released in stratospheric flights of supersonic aircraft was considered.\nThis brought worldwide attention to the potential for a global problem, an in-\ncrease in biologically harmful UV radiation at the Earth's surface, caused by\nthe reduction in stratospheric ozone. Later, chlorine-containing halocarbons\nand nitrogen fertilizers were identified as potential threats to stratospheric\nozone. In addition to the effects of increased UV radiation on biological\nsystems, changes in the chemical composition of the atmosphere may also pro-\nduce climatic changes.\nTwo major environmental problems are associated with the chemistry of the\ntroposphere: photochemical air pollution and acid precipitation. Photochern\nical air pollution or smog is generally limited to urban and near-urban areas.\nIt involves the formation of chemicals such as ozone and peroxy compounds,\nwhich damage or irritate plants and animals. These chemicals are generated in\nair by a complex reaction scheme involving nitrogen oxides, oxygen, hydrocar-\nbons, carbon monoxide, and sunlight. Usually the reactant chemicals are\ntransformed into their toxic products in the vicinity of the source. In acid\nprecipitation, sulfur and nitrogen source compounds may travel over large dis-\ntances before they are transformed into strong acids that are deposited in\nremote rural locations. The acids may cause direct damage or they may dis-\nsolve compounds releasing toxic metals that can damage plants and wildlife.\nMost chemical reactions that take place in the troposphere and stratos-\nphere involve free radicals. These are atoms or molecules and are character-\nized by high reactivity, which often results from having one or more unpaired\nelectrons. These reactions define the formation and destruction of atmos-\npheric ozone, the oxidation of natural and anthropogenic chemicals released\ninto the atmosphere, and the formation of acid rain. The Atmospheric Chemical\nKinetics program emphasizes quantitative studies of the rates and mechanisms\nof the important gas phase reactions of atoms and radicals. Studies are made\nover a wide range of temperatures and pressures to simulate conditions in the\natmosphere.\nAccomplishments FY 1985\nAL\nTwo experiments, a laser magnetic resonance (LMR) spectrometer and a\nchemicaliionization flowing afterglow (CI-FA), are being used to study the\nmechanism by which sulfur dioxide (SO2) is converted to sulfuric acid (H2SO4)\nin the atmosphere. This process is a major source of uncertainty in modeling\nacid precipitation chemistry. A central issue is whether odd hydrogen radi-\ncals, OH or HO2 are consumed in the conversion process. If radicals are con-\nsumed, a reduction in SO2 emissions would not necessarily produce a propor\ntionate reduction in the amount of H2SO4 deposited in critical areas. This\nfollows because the present rate of H2SO4 production may be limited by the\nnumber of odd hydrogen radicals produced and not by the amount of SO, 2 released\ninto the atmosphere. Experiments in other laboratories have provided indirect\n205","evidence that the gas phase SO, oxidation process may not consume radicals.\nIn FY 1983 our direct LMR study confirmed these experiments and showed that\nthe OH radical that reacted with SO2 in the primary process was regenerated as\nan HO 2 radical, when oxygen was present. We have now exploited this\nobservation to conduct further studies of the intermediate, HOSO 2, radical.\nUsing LMR spectroscopy to observe the HO2 product of the HOSO 2 + O2 reaction,\nwe have measured the rate coefficient at room temperature. The yield of HO 2\nhas also been measured by LMR. The CI-FA experiment has been used to directly\ndetect both the HOSO2 reactant and SO3 product. The rate coefficient for the\ncritical HOSO2 + O2 reaction has been measured directly by following the HOSO,\nconcentration\nThe reaction of nitrate radicals, NO 3, with nitric oxide\nNO 3 + NO 2NO2\nhas been studied using laser-induced fluorescence detection of NO 3 This re-\naction is used for laboratory calibrations of NO concentrations and is import\ntant in nighttime urban chemistry. In FY 1984 the rate coefficient had been\nmeasured as a function of temperature for the first time. Studies in FY 1985\nshowed that below room temperature the rate coefficient increased with\ndecreasing temperature, but above room temperature it did not change with\ntemperature. Such nonlinear behavior has been observed in other radical\nreactions.\nThe kinetics and transport properties of gaseous sodium (Na) have been\nstudied in a fast-flow reactor with resonant fluorescence detection of Na.\nSodium is deposited in the upper atmosphere by meteors. It was recently pro-\nposed that the presence of Na in the stratosphere could modify the chemistry\nof chlorine species that have been shown to be effective ozone destruction\ncatalysts. The reaction of Na with N20 was found to be an excellent kinetic\nsource of NaO. Using this source, we studied the reactions of NaO with H2 2,\nH2O, CH4, and NO. All react quite rapidly except CH4 whose reaction is slow.\nOne surprising result is that the NaO + H2 reaction regenerates Na on about\n30% of the collisions. This mechanism indicates an unusual amount of re-\narrangement for an elementary reaction. The diffusion coefficients of Na in\nNe, Ar, N 2 and CO2 were measured at room temperature. Some of the results\nwere compared with other experimental data, using Chapman-Enskog theory.\nThe mechanism for the atmospheric oxidation of hydrogen sulfide, H2S, is\nbeing investigated. The objective is to determine the extent to which this\ncompound of natural origin can contribute to the production of sul- furic acid.\nThe first study focused on the chemistry of the HS radical. First, two kinetic\nsources for generating HS in a discharge flow reactor were developed. Then by\nuse of laser magnetic resonance (LMR) detection, the rate coefficient for the\nreaction of HS with NO 2 was measured. The value at room temperature is\ndifferent by about a factor of 2 from the result published by another\nlaboratory. It was proposed that previous data contained an error due to\nsecondary chemistry. The HSO product of the HS + NO 2 reaction was also\ndetected by LMR.\nA new experiment employing a high-resolution Fourier transform spectrom-\neter (FTS) was developed to evaluate the products and intermediates of atmos-\npheric radical reactions. The experiment consists of radical sources, a\n206","reactor, a 1.6-m-long multipass absorption cell with a high-speed pump, and\nthe Fourier transform interferometer. Initial tests with this system demonr\nstrated that product molecules are detectable at concentrations down to 10 10\nor 10 11 molecules cm ³ . The first kinetics study with this experiment was on\nthe reaction of OH with NO This reaction is the major source of nitric acid\n(HNO 3 ) in the atmosphere and is an important removal process for both OH and\nNO radicals. Our objective was to find if HNO 3 is the exclusive product of\nthis important reaction or if the isomer peroxynitrous acid, HOONO, is also\nformed. Searches at several different wavelengths in the infrared region were\nunsuccessful, and no evidence of the HOONO species was produced. From in-\nfrared measurements of the amount of HNO 3 formed, it was concluded that the\nyield of HNO 3 is 80% or greater. The FTS was used also to record the absorp-\ntion spectrum of all three of the fundamental infrared bands of the HO 2 mol-\necule. These data demonstrate the potential of this experiment to take\nspectra of polyatomic transient species and they are useful in analyzing for\nHO 2 lines in atmospheric absorption spectra.\nThe reaction of HO2 radicals with ozone is very important in stratos-\npheric and tropospheric chemistry as a mechanism that destroys ozone.\nHO 2 + 0 3 OH + 202\nIn the atmosphere it is coupled with the reaction of OH with ozone,\nOH + 03 HO 2 + O2\n,\nand these taken together demonstrate how the odd hydrogen radicals OH and HO2\ncan catalytically destroy ozone. There has been only one direct study of the\nHO 2 + 0 3 reaction and that was done in the Aeronomy Laboratory about 5 years\nago. The difficulty in studying this reaction is that the OH + 03 reaction is\nmuch faster and regenerates the HO 2 reactant. The new approach to this\nproblem was to use isotopically labeled HO2 molecules that cannot be\nregenerated. Preliminary results at room temperatures using isotopically\nlabeled oxygen in the HO, were in good agreement with the previous study.\nA new experiment using pulsed laser photolysis and pulsed-laser-induced\nfluorescence was assembled. This apparatus was designed to study reactions at\npressures up to 1 atmosphere. As a test of this system, the photophysics of\nNO were investigated. The radiative lifetime and some quenching rate coeffi-\ncients for the first electronically excited state (A2E) of NO were measured.\nSeveral studies of ion-molecule kinetics were completed in collaborations\nwith scientists at several institutions. The reaction of O2 with CH4 was\nAL\nstudied under a wide variety of experimental conditions. Although this re-\naction is very complex, a great deal was learned about the details of its\nmechanism. The deactivation of excited diatomic species in ion-molecule re-\nactions was also studied. Rate coefficients for deactivation of vibrationally\nexcited N 2 by NO+ and of electronically excited O2 by NO+ (v=1) were\nmeasured.\n207","Plans FY 1986\nThe SO2 oxidation study will be completed. The chemical ionization\napparatus will be used to evaluate the temperature dependence of the HOSO2 +\nO2 reaction and to measure the yield of SO3 from this reaction. An attempt\nwill be made to determine the thermochemistry of the HOSO, 2 radical by exam-\nining the reverse reaction, HO 2 + SO3.\nA new experiment utilizing vacuum UV photoionization mass spectrometric\ndetection of free radicals will be developed. A prototype hydrogen Lyman\nalpha light source has been tested and has demonstrated a detection limit of\nabout 10 8 molecule for nitric oxide. As a first test of this experiment,\nthe products of the NO ² + 03 reaction will be examined. The long-term objec-\ntive of this experiment is to study the mechanisms for atmospheric hydrocarbon\noxidation. These reactions are a central part of tropospheric chemistry since\nthey play a role in oxidant production and they involve all major free radical\nfamilies.\nThe studies of NO 3 radical kinetics will be continued. The next reac-\ntions to be examined are those of NO 3 with reduced sulfur compounds such as\nhydrogen sulfide and dimethylsulfide. Since NO is a nighttime radical\nreactant, these studies will examine the possibility that there is nighttime\nradical chemistry involving sulfur species. If there are significant reac-\ntions among these chemicals, other reactive radicals may be produced, and\nperhaps other aspects of nighttime chemistry should be examined.\nThe kinetics of Na and its compounds will be extended to include studies\nof the temperature dependence of some selected processes. First, the temper-\nature dependence of some Na diffusion coefficients will be measured. These\nresults will be compared with the predictions of the ChapmanmEnskog model,\nusing published data on Naminert gas potentials. The temperature dependence\nof some Na and NaO reactions will also be examined. Some reactions of NaO\nwith organic compounds will be studied to determine how NaO reaction mecha-\nnisms parallel other reactants.\nThe analysis of the H2S oxidation mechanism will be continued. First the\ntemperature dependence and product analysis of the HS + NO 2 reaction will be\ncompleted. Then the kinetics of the HS + O 3 reaction will be examined. A\nstudy of HSO kinetics has been initiated. Some details of the kinetic sources\nof HSO still need to be established. The first studies of the chemistry of\nthis radical will include the reactions of HSO with O2, NO 2 , and 03.\nThe Fourier transform spectrometer will be used to examine the high-\nresolution spectrum of gaseous molecules. First, searches will be made for\nthe transient species HOSO 2 and HSO. Both of these radicals are important\nintermediates in acid precipitation chemistry. Next, the reaction of HO 2\nradicals with NO will be studied to determine the relative yields of HONO and\nHOONO 2 2 products. The formation of significant amounts of HONO in this reac\ntion would be an important finding because this molecule is rapidly photolyzed\nto produce highly reactive OH and NO radicals. The HOONO 2 molecule, on the\nother hand, has very different atmospheric effects. The high-resolution spec-\ntrum of HOONO 2 will be examined for the purpose of providing data that can be\nused to make quantitative measurements of HOONO 2 in the atmosphere, using\ninfrared spectroscopy.\n208","The kinetics study of the HO, + 0 3 reaction, using isotoperlabeled HO2\nradicals, will be completed. The mechanism of the reaction will be examined\nby measuring the yield of isotope-labeled OH product. A few other atmospheric\nreaction mechanisms will be studied using similar isotope-labeling techniques.\nAt night, N2O5 is a major odd-nitrogen reservoir in both the stratosphere\nand the troposphere. During sunlit hours, N2O5 is photolyzed to release the\nactive NO X species (NO 3, NO , 2, and NO). The products of N2O5 photolysis are\nuncertain. NO 3 and O(SP have been identified as products and their quantum\nyields measured in the wavelength range 248-305 mm. To completely understand\nthe photolysis process, the quantum yields for NO as a function of wavelength\nare needed. The NO quantum yields will be measured by laser-induced fluores-\ncence following N2O photolysis by an excimer laser or a Nd:YAG pumped-dye\nlaser system. The wavelength range of 248 to 305 mm will be covered.\nIn the methane oxidation cycle a major subject of uncertainty is the\nchemistry of CH300H. The rate coefficient for the reaction of OH with CH3OOH,\none of the CH300H removal mechanisms, will be measured as a function of tem-\nperature. A pulsed Xe lamp will be used for photolytic production of OH.\nPulsedPlaser-induced fluorescence will be used to follow the OH concentration\nduring the reaction. Information regarding the products of the reaction will\nbe obtained by isotopemlabeling the reactants. The quantum yield for the\nproduction of OH in the photolysis of CH3OOH will also be measured using the\nsame experimental technique.\nCarbonyl sulfide (COS) is believed to be quite inert in the troposphere.\nBut it is possible that its reaction with OH is enhanced by the presence of\nO2, just as the analogous reaction of CS 2 with OH is much faster when O2 is\npresent at high pressures. This possibility will be investigated using the\nsame apparatus and methodology as those used in the study of OH + CH 3 OOH\nreaction.\nNO 3 is known to be an important intermediate in the troposphere as well\nas in the stratosphere. Its atmospheric concentration is usually measured\nusing long-path absorption at 662-nm wavelength. To calculate concentrations\nfrom measured absorbances, the value of the absorption cross section at the\natmospheric temperature is needed. Preliminary investigations have shown that\nthe absorption cross section of NO 3 in the 662-nm band is temperature depen-\ndent, contrary to previous belief. Therefore, the temperature dependence of\nthe entire NO 3 spectrum will be investigated. Two flowtubes will be used in\ntandem, in conjunction with two diode array spectrometers. By this method the\nrelative changes in cross sections with temperature will be measured. N2O5\nAL\nthermolysis will be used to produce NO 3 , and titration with NO will provide\nthe absolute NO 3 concentration.\nThe major source of odd-nitrogen in the stratosphere is the reaction of\nO( D') with N20. The major loss process for N2O in the stratosphere is photol-\nysis in the 190-210 nm wavelength region. Experimental investigations will be\ncarried out to assess the possibility of NO production directly from N2O pho-\ntolysis, and to measure the NO production rate from the (1D) reaction with\nN20 under stratospheric conditions. Laserinduced fluorescence detection of\nNO will be used to measure NO.\n209","ATMOSPHERIC DYNAMICS\nThe objective of the Atmospheric Dynamics Program is to further our\nunderstanding of the dynamics of the atmosphere, particularly mesoscale and\nsmall-scale dynamics of the free atmosphere. Thus, we devote most of our\nresearch to the study of internal gravity waves (also called buoyancy waves),\nturbulence, etc. These mesoscale and small-scale processes are important for\nseveral reasons: (1) They are important problems in atmospheric and, more\ngenerally, geophysical fluid dynamics. (2) They are the meteorological\nbackground noise against which synoptic-scale measurements are made.\n(3) Gravity waves transport energy and momentum upward from sources in the\nlower atmosphere to sinks in the upper atmosphere. (4) Gravity waves are\nthought to be the source of all of the turbulence in the free atmosphere,\nwhich is the cause of most of the energy dissipation in the free atmosphere\nand part of the vertical mixing and transport of trace species. The study of\nmesoscale and small-scale processes takes advantage of the unique experimental\nand analytical capabilities of the group.\nThe observational base for the research of the Program consists largely\nof measurements of wind profiles obtained using the MST (Mesosphere-Strato-\nspherenTroposphere) radar technique. This technique measures the wind in the\nclear air, using very sensitive Doppler radars. Since such radars can measure\nwind profiles as often as every minute, about 1000 times faster than routine\nballoons or rockets, they are uniquely suited for studying phenomena that vary\nrapidly in time, such as gravity waves and turbulence.\nAccomplishments FY 1985\nAIR QUALITY\nThe MST radar technique measures the radial velocity versus time and\nradial range, leading to power spectra of radial velocity versus radial\nwavenumber. On the other hand, model gravity wave spectra are expressed in\nterms of vertical and horizontal velocities as a function of vertical and\nhorizontal wavenumbers. In order to interpret MST radar spectra, we derived\nmodel radial spectra from the normal spectra. These model radial spectra\nagree well with radial spectra in the summer mesosphere observed by the Poker\nFlat MST radar near Fairbanks, Alaska, showing that the observed spectra were\ndominated by gravity waves.\nThe usual models of gravity wave spectra, and the fluid dynamical\ntheories that support them, apply to intrinsic spectra, that is, spectra in a\nreference frame moving with the background wind. Radars, on the other hand,\nobserve in a fixed reference frame, so that they observe a Doppler-shifted\nintrinsic spectrum. In order to gain insight into the meaning of the observed\nspectra, we started to develop a model for the calculation of Doppler-shifted\nspectra from intrinsic spectra.\nWe showed that, although the energy in gravity wave frequency spectra\nincreases by a factor of several hundred from the troposphere to the meso-\n210","sphere, the energy in vertical wavenumber spectra does not increase signifi-\ncantly. This anomaly has been explained in terms of a model for the satur-\nation of gravity wave spectra as they propagate upward through the atmosphere.\nIn July and August 1983 we studied the generation of gravity waves by\nthunderstorms, or, more generally, the relation between gravity waves and\nthunderstorms, using an array of existing ST (stratosphere-troposphere radars\ntogether with a network of 22 microbarographs in northeastern Colorado. We\nfound that on some occasions the gravity waves and the thunderstorms move\ntogether, suggesting that the gravity waves initiate the convection and that\nperhaps the convection reinforces the gravity waves.\nAs the antennarpointing direction of a radar operating at lower VHF\nfrequencies is moved from an oblique angle to the zenith, the reflectivity is\noften greatly enhanced by partial specular or Fresnel reflection from hori-\nzontal stratification of the radio refractive index. However, there has been\ncontroversy over the dependence of the Fresnel reflectivity on the radar range\nresolution. Careful measurements of this dependence made with the Sunset\nradar showed that, in most cases, the reflectivity from stable layers was\nlinearly proportional to the effective length as predicted by simple theory;\nin a small fraction of cases the reflectivity varied as a larger power (up to\n2) of the effective length.\nFrom 23 January to 10 February 1984 and from 23 January to 1 March 1985,\nthe Sunset radar was used to measure the wind, particularly the vertical com-\nponent, over the Front Range of Colorado in an FAA-sponsored experiment to\nassess the reliability of aircraft altimeters over mountains. As part of this\nexperiment, many other meteorological sensors were operated by the FAA, NCAR,\nWPL, and NWS.\nThe rapid, ground-based measurement of wind velocity is an important\nmeteorological capability of ST radars. The Sunset radar was used to test\nthe consistency of ST radar wind measurements by comparing horizontal vectors\ncalculated in several ways from the radial velocities measured with five\nantenna beam positions. It was found that the inclusion of the measured\nvertical velocity in the calculation of the horizontal wind vector velocity\nresults in a significant improvement in the estimation of the horizontal wind\nvelocities.\nPlans FY 1986\nAL\nAIR QUALITY\nWe will continue to study the gravity wave field and its effects. In\nparticular, the model for radial velocity spectra will be generalized to\ninclude wave fields that are azimuthally anisotropic. The parameters of the\nanisotropic spectra will then be determined by comparing the model with\nobservations from ST radars. These anisotropic spectra will be used later to\nexamine gravity wave propagation (and subsequent transfer of horizontal\nmomentum) from the troposphere through the stratosphere into the mesosphere.\nThe model study of Doppler-shifting of intrinsic spectra will be completed.\n211","Studies of the vertical flux of horizontal momentum will be extended, using\ndata from the Sunset radar and other radars.\nWe will also continue to study methods of deriving the total wind vector\nfrom radial velocity measurements. This study is particularly timely because\nof the development of ST radars or wind profilers for operational wind sound-\ning and their use in major experiments such as the STORM~Central phase of the\nNational STORM Program, which will deploy up to 70 ST radars.\nMost existing middle- and high-latitude ST radars are in or near regions\nof strong topographic relief. The lee waves generated by the terrain often\nvitiate the interpretation of the data. For the nation to have radar capabil-\nity in a location free from this effect, we have proposed to the National\nScience Foundation to construct and operate a state-of-the-art ST radar in\nvery flat terrain near Urbana, Ill. University atmospheric science groups\nwill collaborate, both in experiments and in the analysis of data. Extensive\ndesign studies have been conducted using existing radar data to determine the\noptimum system configuration for the proposed experiments. Innovations resul-\nting from these studies are being tested with the Sunset radar. If the Flat-\nland radar is funded, studies with it will constitute a major new direction\nfor the Air Quality program.\nTROPICAL DYNAMICS AND CLIMATE\nA growing awareness of the profound role of the tropics in influencing\nour global weather and climate patterns has resulted in the formation within\nthe Aeronomy Laboratory of the Tropical Dynamics and Climate/Program.\nIn general terms, the purpose of this newly formed program area is to\nstudy, by radar techniques and ancillary data bases, the effects of small- and\nmeso-scale dynamic processes (e.g., gravity waves, turbulence, and convection)\nin the tropical atmosphere on worldwide climate. Associated tasks include\nstudies of relatively short-term climatic variations, exemplified by the\nrecent El Niño event, which had disastrous effects over a significant portion\nof the globe.\nThe Tropical Dynamics and Climate program can contribute uniquely to such\nstudies by making use of its extensive expertise in developing and using wind-\nprofiling radar systems. Wind profilers were originally developed by AL sci-\nentists as an outgrowth of initial studies at Peru's Jicamarca Radar Observa-\ntory, itself a former AL project. The Laboratory designed the large MST\n(mesospherenstratosphere-troposphere) radar at Poker Flat, Alaska, and has\noperated it for the past 6 years. AL recently established a pair of more\nconventional profilers in the tropical Pacific at Ponape (E. Caroline Islands)\nand Christmas Island (Republic of Kiribati). Similar systems have been used\nin temporary experimental programs in Colorado, Oklahoma, and Southern France.\nThe Laboratory also designed and operates, with WPL, a profiler in\nPlatteville, Colo., that served as a prototype system for WPL's current pro-\ngram to establish a mesoscale network of similar systems throughout the\nMidwest, to provide high-resolution wind profiles for the National Weather\nService.\n212","Wind profilers are capable of providing height profiles of the total wind\nvector, atmospheric waves and turbulence, spectral kinetic energy density, and\ngravity wave momentum flux. They can also provide a continuous measurement of\nthe tropopause height. In addition to their ability to obtain continuous\ndata, another major advantage of profilers over more conventional balloon-\nborne systems is that profilers measure the vertical wind. Although this pa-\nrameter is considered to be a major factor in a variety of atmospheric pro-\ncesses, it is virtually unmeasurable on a continuous basis by any other tech-\nnique. Profiler operation is continuous, relatively inexpensive, and\nessentially unattended.\nAccomplishments FY 1985\nCLIMATE\nThe Aeronomy Laboratory's Poker Flat MST radar in Alaska ceased normal\noperation in April 1985, following more than 6 years of almost continuous data\ntaking. During this period, the radar produced data on atmospheric winds and\nrelated parameters in the troposphere, lower stratosphere, and mesosphere.\nTechnological spin-offs from Poker Flat resulted in the formation of at least\none small business in Boulder's private sector. This radar, which was funded\nprimarily by the National Science Foundation, is being reconfigured and the\nexisting data set is being archived for use by the scientific community (see\nPlans, FY 1986).\nThe Ponape wind profiler, which was established in the Central Pacific in\nMay 1984, produced some 16 months of continuous data on vertical winds in the\ntroposphere and lower stratosphere. A preliminary analysis of the mean verti-\ncal motion showed upward motion in the troposphere during convective episodes\nand weak downward motion at times of little or no convective activity. Spec-\ntral analysis of the quiet periods between convective episodes revealed a\npower spectrum very similar to the observed spectrum of internal waves in the\nocean.\nA second profiler in the tropical Pacific is being established on Christ-\nmas Island (Republic of Kiribati) with funding from Project TOGA (Tropical\nOceans and Global Atmosphere). In addition to the high-time-resolution data\nobtained for analysis within the program area, 6-hourly data from the\nChristmas Island radar will be telemetered via GOES satellite and transferred\nautomatically onto the Global Telecommunication System (GTS) for worldwide\ndistribution. Establishment of a remote wind profiler on Christmas Island\nAL\nrepresents a major milestone in remotely monitoring winds from remote\nlocations.\nUsing theories developed in-house, we established that profiler echoes\ncan be used to continuously monitor the height of the tropopause with an rms\nerror of a few hundred meters. Radar determination of the tropopause to this\naccuracy is more than adequate to aid the retrieval of temperature profiles,\nusing satellite and ground-based radiometry.\nWe have compiled a climatology of the quantity of Cn 2 using long-term\nobservations of radar reflectivities from Poker Flat and Platteville. This\n213","quantity is very important in electromagnetic wave propagation in the atmos-\nphere, as well as a useful proxy indicator of eddy dissipation rate, an impor-\ntant parameter of atmospheric turbulence. The climatological studies revealed\nthat Cn2 is logenormally distributed and has significant seasonal and diurnal\nvariations.\nFrequency spectra of vertical velocity fluctuations in the troposphere\nand lower stratosphere were obtained by profilers from a variety of geograph\nical locations. Comparisons of these spectra, which were obtained at sites\nfrom the Arctic to the Equator and from the central plains to the middle of\nthe ocean, show remarkable similarities but some significant differences, and\nattest to the general universality of the spectrum of vertical atmospheric\nmotions.\nIn addition to measuring frequency spectra by radar, we recently com-\npleted a climatological study of wavenumber spectra of winds and temperatures\nmeasured by commercial aircraft during routine flights. Briefly, the analysis\nreveals the remarkable result of a nearly universal and comparable spectrum\nfor wind and temperature. Scale sizes ranging from a few kilometers to\n5,000 km are resolved in the analysis.\nA direct measurement of the mean large-scale vertical motion of the\natmosphere was achieved by averaging vertical velocities measured by a wind\nprofiler at a single station. Under ideal conditions, it can be demonstrated\nthat these directly measured vertical velocities are comparable with vertical\nvelocities inferred from NMC analyses. In a related case study, vertical\nmotions observed by the Platteville radar were shown to be well correlated\nwith rainfall rates observed near by during an upslope storm.\nHeight profiles of the average kinetic energy density of the atmosphere\nwere extracted from the Poker Flat MST radar data base. The results are con\nsistent with the idea that atmospheric gravity waves, which are generated in\nthe troposphere, grow in amplitude as they propagate upward into the more\nrarified atmosphere. This growth is limited by wave saturation; the excess\nwave energy is eventually deposited into in situ turbulence or modifies the\nlocal mean flow. The emerging picture is one in which large height regions of\nthe atmosphere, between 1 and 100 km, contain a fully saturated spectrum of\nwaves. In other height ranges, specifically in the lower stratosphere, wave\nsaturation is not complete because the upwardrpropagating waves are being\nmodified by other processes.\nA study of interannual variability of tropopause heights over a wide\nrange of tropical longitudes from the western Pacific to the eastern Atlantic\nwas completed. The height of the tropopause was found to vary coherently over\nthis spatial range on interannual time scales, and to be related to both the\nquasi-biennial oscillation in tropical stratospheric winds and to the phase of\nthe southern oscillation.\nA relationship between tropical tropopause heights and the global angular\nmomentum of the atmosphere found earlier, using monthly mean data, was extend-\ned using atmospheric angular momentum data at 3-day intervals. Preliminary\nresults showed that the correlation takes place mainly within the tropics\nthemselves; i.e., there is a highly significant correlation between tropopause\nheight variations in the western tropical Pacific and variations in the\n214","height-integrated, zone-integrated winds in the +15° latitude belt. The\ninterpretation of these results is not yet complete, but the key role of\ntropical convective activity in the global-scale dynamics of the atmosphere is\nalready clear.\nThe effect on tropopause heights of the stratospheric aerosol cloud\ngenerated by the eruption of the El Chichon volcano in April 1982 was investi-\ngated using data from the western tropical Pacific. The behavior of tropo-\npause heights and potential temperatures leads to the conclusion that the\ninfluence of El Chichon was largely canceled out by the opposing influence of\nthe great ENSO (El Niho/Southern Oscillation) event during the latter half of\n1982.\nAlso, using the long-term data base of tropospheric, stratospheric, and\nmesospheric wind available from Poker Flat, we investigated possible changes\nin velocity fluctuation statistics following El Chichon. In the lower atmos-\nphere, the variance of horizontal winds was found to be significantly lower in\nearly 1983 compared with 1982 and 1984. At mesosphere altitudes, an increase\nin tidal energy was found. This increase would be expected to follow enhanced\nheating in the lower stratosphere.\nPlans FY 1986\nCLIMATE\nAs mentioned before, the Poker Flat MST radar is being modified for a\nbeam-steering capability in order to measure gravity wave momentum flux (GWMF)\nand associated phenomena. The determination of a climatology of GWMF is con-\nsidered to be a crucial factor in our eventual understanding of global atmos-\npheric circulation.\nAn additional effort will be to prepare an archive of the Poker Flat\n6-year data set. This archive, when complete, will be transferred to the\nNational Center for Atmospheric Research (NCAR) for use by the scientific\ncommunity. The data set will also continue to be studied within the program\narea to establish long-term trends in gravity wave and turbulence activity,\nand the seasonal characteristics of the height distribution of these\nparameters.\nThe vertically directed radar profile at Ponape, which produced contin-\nuous vertical wind data, will also be reconfigured into a beam-steerable\nAL\nsystem for GWMF measurements. These measurements will provide an exciting\nfirst look at the vertical distribution and character of GWMF in the tropics.\nOperation of the Christmas Island profiler will begin, following the\ninstallation of a diesel generator to provide continuous power to the station.\nInclusion of the Christmas Island data set in our existing Ponape data set\nwill stimulate a number of preliminary studies of the short-term dynamics of\nthe tropical atmosphere.\nIn addition to our activities at Ponape and Christmas Island, we will\ncontinue to examine other sites to complete our Tropical Pacific chain. In\n215","general, the most crucial tropical regions that should be included lie in the\nwestern edge of the Pacific Basin (i.e., , near Indonesia and Malaysia) and in\nthe region containing the Galapagos Islands and the Ecuadorian-Peruvian coast.\nPreliminary site surveys have been made in both regions.\nWe will begin an intensive study of the climatology of convective dynam-\nics by combining the existing 16-month data set from the Ponape radar with\nadditional data sets from satellites and rawinsondes. In addition, if we can\nidentify the small, long-term mean vertical motions in the radar data associ-\nated with the large-scale Hadley and Walker circulation cells, we will begin\nto explore the variability of these circulations within the context of the\nbroad-scale features of tropical dynamics being explored by TOGA.\nStudy of the tropical tropopause region, using radiosonde data, will\ncontinue. Emphasis will be on (1) completing the study of the relationship\nbetween tropopause heights and atmospheric angular momentum, (2) studying the\neffects of the ENSO event of 1982-83 on the tropical tropopause region, (3)\ninvestigating the relationship between anomalies in Pacific sea surface tem-\nperatures and in atmospheric temperatures in the tropical upper troposphere\nand lower stratosphere, and (4) developing a conceptual picture of the mecha-\nnism of troposphere-stratosphere exchange in the tropics.\nIn order to improve this lower limit of current profile technology and to\nprovide higher resolution in the first 2 to 3 km of the atmosphere, we are\ndesigning an inexpensive \"Boundary Layer\" radar that will operate at much\nhigher frequencies and be capable of observing the region between about 300 m\nand 2 to 3 km altitude. This system will supplement our existing VHF system\non Christmas Island.\nATMOSPHERIC WAVES AND TURBULENCE THEORY\nThis program is devoted to theoretical studies of turbulence, waves, and\neddy transport in the atmosphere. These phenomena are basic to many areas of\ngeophysics, including meteorology, climatology, pollution dispersal, ocean-\nography, space physics, and aeronomy.\nWave and turbulence fluctuations are present in vast regions of the at-\nmosphere because the natural state of the atmosphere is often locally unstable.\nSuch fluctuations have a striking effect on transport of pollutants and were\nintensively observed as long as two decades ago. However, because of mathe-\nmatical and conceptual difficulties, no theories of turbulence and nonlinear\nwave interactions were available for determining the strength of these fluc-\ntuations and how they influence pollution dispersal and meteorology. The\ndevelopment of such theories has become a principal concern of this program\nduring the past decade.\nAccomplishments FY 1985\nThe Atmospheric Waves and Turbulence program (1) calculated the manner in\nwhich a gravity wave \"breaks\" in the atmosphere, and presented arguments to\n216","establish this \"breaking\" to be the principal process by which waves cause\nmass transport in the atmosphere; (2) determined the influence of stable\nstratification on the pressure-strain term, a crucial term of boundary layer\nmodels; (3) explained observed (MST) mesospherenstratospheremtroposphere radar\nspectra as being caused by strongly interacting gravity waves with an impor-\ntant consequence for atmospheric transport; (4) determined the spectrum of\ntemperature fluctuations in atmosphere and oceans, and corrected a commonly\nquoted 20year-old error in the literature concerning such spectra; (5) proved\nthat \"return to isotropy\" the principal hypothesis of turbulence models--is\ninvalid, and developed a theory to determine realistic deviations from\nisotropy; (6) theoretically determined how observed height variations of\ngravity wave amplitudes can be used to infer eddy diffusivities in the middle\natmosphere; (7) discovered a nonlinear instability by which gravity waves\ncause local fluid overturns and turbulence in the middle atmosphere.\nPlans FY 1986\nThe following studies of turbulence in the atmosphere are planned:\nContinue to develop a reliable turbulence model of the planetary boundary\nlayer by applying contemporary methods of turbulence theory. This year's\ngoal is to calculate the influence of stress and dissipation anistropy\nupon the planetary boundary layer.\nDevelop theory to explain the turbulence \"collapse\" phenomena recently\nobserved in laboratories, and almost certainly occurring in the\natmosphere.\nContinue efforts to explain theoretically, and calculate, the apparently\nuniversal spectrum observed for vertical scales of fluctuations in oceans\nand the atmosphere.\nDetermine if there exists a theoretical relationship between observed\ntemperature and velocity fluctuations in the atmosphere.\nContinue work applying theory to the boundary layer model currently used\nby the Naval Environmental Prediction Research Facility (NEPRF). Even-\ntually, the NEP RF facilities will be used to test and expand the theory.\nPlanned studies of gravity waves include continuation of theoretical in-\nvestigations of the spectral distribution, and harmonics, of atmospheric grav-\nAL\nity waves; theoretical search for unidentified instabilities by which gravity\nwaves cause turbulence and transport; continuation of an attempt to determine\nthe \"sink\" of gravity wave energy in oceans and atmosphere; continuation of\nthe modeling of diffusion and friction from 20H to 100-km altitude, the dynam-\nical coupling of the troposphere to the mesosphere, the influence of gravity\nwaves on the mean flow circulation, the role of tidal waves in atmospheric\ndiffusion, and the interaction of gravity waves with airglow and minor atmos-\npheric constituents; determination whether there is a connection between\ngravity wave heat flux and temperature spectra in oceans and atmospheres.\nMajor effort will be given to determine the nonlinear properties of gravity\nwaves from a rigorous, yet simple, analytical approach.\n217","","Harold Leinbach\nSPACE CENVIRONMENTLABORATORY\nActing Director\nBoulder, Colorado\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nSEL\nARL\nAL\nWPL\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nThe Space Environment Laboratory (SEL) is unique in ERL in providing\naround-the-clock, real-time forecasts and warnings of solar and space distur-\nbances, and at the same time, conducting research to support and improve the\nservice activities.\nThe center of the nation's present solar-terrestrial services is the\nSpace Environment Laboratory at Boulder, Colo., where, with the cooperation of\nthe U.S. Air Force Air Weather Service (AWS), monitoring and forecasting\nservices are carried out to meet a wide variety of civilian, military,\ncommercial, and Federal agency requirements. Laboratory activities include\nreal-time collection of solar-terrestrial data, issuance of forecasts, alerts\nand warnings of adverse solar-terrestrial conditions, archiving and processing\nof global data from satellites and observatories, and development of a better\nunderstanding of the behavior of the solar-terrestrial environment to yield\nsignificant service improvements.\nSEL is composed of three Divisions: the Research Division, the Systems\nSupport Division, and the Space Environment Services Division. The three di-\nvisions work cooperatively in providing real-time space environment services\nand conducting the necessary supporting research and development activities.\nSEL\nThe accomplishments of 1985 include these highlights:\nThe new Space Environment Laboratory Data Acquisition and Display\nSystem (SELDADS II) was dedicated. It will be steadily improved and\ntested before it completely replaces the old system.\nThe SEL Solar Image System (SELSIS) began operation, acquiring solar\nimages from Kitt Peak National Observatory and Holloman AFB in digital\nform. The system will be expanded and improved to take advantage of\n219","higher resolution of images and capabilities for data manipulation in-\nherent in the digital data.\nAn initiative for the installation of Solar X-Ray Imagers on GOES\nsatellites I-M was submitted.\nAs a pilot project, SEL collaborated with the Computer Science and\nPsychology Departments of Colorado University to construct a small\nexpert system emulating sunspot classification and solar flare fore-\ncasting methodology.\nA new scientific workstation system was begun to provide interaction\nwith the DOC and SELDADS II computer systems for the display and ma-\nnipulation of scientific data.\nThe Space Environment Services Center (SESC) provided solar-terres-\ntrial support to the Shuttle program, particularly Shuttle orbiter\nChallenger/Spacelab 2 having a complement of solar telescopes that\nmade new discoveries about the Sun.\nAt the end of FY 1985, the President's budget for FY 1986 did not include\nfull funds for SEL research.\nSPACE ENVIRONMENTAL SERVICES\nThe Space Environment Services Division contains the Space Environment\nServices Center (SESC) and Real-Time Data Services (RTDS). SESC is operated\njointly by the National Oceanic and Atmospheric Administration (NOAA) and AWS.\nSESC provides predictions, alerts, and real-time information describing solar\ngeophysical disturbances to users throughout the United States. In addition,\nit is designated the World Warning Agency (WWA) for the International Ursigram\nand World Days Service (IUWDS), which is operated under the International\nCouncil of Scientific Unions. The Real-Time Data Services group collects and\nprocesses data from NOAA satellites and ground sensors operated by cooperating\nagencies and from other countries, both through IUWDS and through bilateral\nexchange agreements. The data collected include solar images and measurements\nof other parameters that characterize the Sun, the interplanetary medium, and\nthe Earth's magnetosphere and ionosphere.\nSolar activity forecasts, geomagnetic forecasts, and warnings of events\nin progress, as measured by real-time observations, are valuable to a great\nvariety of users. For example, the NASA space shuttle program uses this in-\nformation in orbital planning, and planning for astronaut safety. Ionospheric\ncommunications, including low-frequency navigation systems (Omega), are dis-\nturbed during strong flares, proton events, and geomagnetic storms; the space\nenvironment forecasts and warnings aid users in coping with the ionospheric\ndisturbances. The orbits of navigational satellites may be modified by in-\ncreased density of the heated upper atmosphere during geomagnetic storms. The\nU.S. Navy issues corrected satellite ephemerides based on the forecast or obt\nserved level of geomagnetic activity. The same magnetic activity can induce\nstrong voltage and current transients in electric power distribution lines,\nleading to possible system outages. In long pipelines, the induced currents\n220","may upset cathodic corrosion protection systems. In both situations, custom\ners utilize geomagnetic forecasts and warnings to minimize adverse effects on\nsystems. Many geophysical prospecting companies using airborne magnetometers\nwill avoid flights during the magnetically disturbed conditions that would\naffect measurements.\nAccomplishments FY 1985\nThe Space Environment Products and Services listed below were provided\nthroughout the year in accordance with an interdepartmental agreement on\nstandard products and services required to meet the multiple needs of various\nFederal agencies and public users (see National Plan for Space Environment\nServices and Supporting Research, 1983-1987, NOAA, FCM-P10-1983).\nSpace Environment Products and Services\nMonitoring Reports\nSolar-geophysical indices (broadcast)\nDaily High-Frequency Radio Propagation Report\nSolar-Geophysical Activity Summary (daily)\nSolar Region Summary (daily)\n7- and 27-day outlook (weekly)\nSolar and geophysical alerts and warnings ( as required)\nPreliminary Report and Forecast of Solar-Geophysical Data (weekly)\nPrimary Report on Solar and Geophysical Activity (daily)\nGeneral purpose data base (SELDADS)\nAlerts\nSolar X-ray index (2 thresholds)\nGeomagnetic K index (4 thresholds)\nGeomagnetic A index (3 thresholds)\nMagnetic storm sudden commencements\nSolar protons (2 thresholds)\nHigh-altitude radiation hazard (1 threshold)\n10-cm solar radio flux (1 threshold)\n245-MHz solar radio flux (2 thresholds)\nType II, Type IV solar radio bursts\nForecasts\nProton events\nSEL\nGeomagnetic variation\nX-ray flares\n10-cm flux\nGeneral level of solar activity\nSmoothed sunspot number\nIn addition to the standard services provided to Federal agencies, uni-\nversities and research groups, commercial users, the general public, and CO~\noperating foreign countries, reimbursable special support was provided to the\nNASA Solar Maximum Mission at NASA/Goddard Space Flight Center and to the\nSpacelab 2 and 3 missions at the NASA/Johnson Space Center.\n221","Data sources used in operation of SESC the previous year were continued\n(see Programs and Plans 1984-1985). Coverage of solar wind disturb- ances\nfrom the NASA Satellite ICE (Interplanetary Cometary Explorer) degraded as the\nsatellite moved away from Earth toward its encounter with the Comet Giacobini\nZinner.\nDuring 1985, solar flare activity was low; thus most geomagnetic activity\nwas associated with coronal holes and disappearing filaments. Such activity\nis more difficult to forecast than geomagnetic activity following large, high\"\nly visible solar flares. Geosynchronous-satellite operators were increasingly\nconcerned about spacecraft charging, which can result in loss of data, upsets\nof satellite orientation, or damaged electronic components. While the cause-\nand-effect relationships are still being established, satellite users are\nattempting to use currently available space environment data in formats not\nwell suited to the problem. Talks were initiated with user agencies regarding\nthe development of indices and other standardized ways to provide information\nto the user agencies.\nOnly 20% to 30% of all solar events including solar flares and energetic\nparticle events are \"geo-effective\", i.e., produce geomagnetic storms. Re-\nsearch indicates that solar mass ejections may be the key to understanding\nwhether solar activity of various kinds will affect the Earth. Following this\nlead, the SESC staff began studies aimed at identifying the characteristics of\nsolar mass ejections that cause magnetic storms; they are using real-time data\nfrom solar mass ejection monitors flown by the U.S. Naval Research Laboratory\non Defense Department satellites.\nThe SESC staff also participated in working groups to help the U.S. Air\nForce define requirements for the next generation of satelliterborne solar\nmonitors, and to define the requirements for and the benefits to be gained\nfrom an X-ray imaging telescope on the GOES satellite.\nPhase I in the implementation of the Space Environment Laboratory Data\nAcquisition and Display System (SELDADS II) was completed; the system was in-\nstalled and attained much of the capability of the older system early in the\nyear. Capabilities will increase as software is implemented in Phases II and\nIII. The system comprises eight micro-based computers networked with a super\nminicomputer to provide parallel, redundant processing for the collection,\nstorage, editing, analysis, and transmission of data, forecasts, indices, and\nalerts into and out of SESC.\nNetworking of the system was completed, and a project to design and in-\nstall the software began. Software design is being driven by a set of service\nrequirements developed by the operational forecast center staff. Design and\nimplementation are being done by a group of analysts, engineers, and program-\nmers from the Services Division and Support Division.\nA preliminary stage of the Space Environment Laboratory Solar Imaging\nSystem (SELSIS) was used to support the Spacelab 2 mission. Digitized solar\nimages were collected from Holloman AFB and Kitt Peak National Observatory\nand displayed at SESC and at the Science Area of NASA/Johnson Space Center,\nHouston, Tex.\n222","Changes in communications included conversion from the obsolescent Astro-\ngeophysical Teletype Network to the modern Continental U.S. Meteorological\nData System (COMEDS) network, and a growth in numbers of users of the SESC\nsatellite broadcast network. This broadcast system permits users to receive\nSESC services directly on their own commercially available receivers, as\nbroadcast from a commercial satellite.\nPlans FY 1986\nThe standard complement of services, including forecasts, alerts, in-\ndices, and advisories, will continue to be provided by SESC.\nStudies into the nature of solar mass ejections will continue. A system\nof numerical guidance will be developed and put on line for the forecast staff.\nA climatological data base, for use in geomagnetic forecasts and solar flare\nforecasts (based on models using parameters provided by the USAF Solar Obser-\nving Optical Network [SOON]), will be established.\nA \"core\" system of SELDADS II will be put into operational service later\nin the year. The functions provided will be sufficient to allow the shutdown\nof the old SELDADS system after a period of parallel operation. The follow-on\nphases of SELDADS II will include the provision of numerical guidance pro\ngrams, full real-time handling of all satellite and magnetometer data (exceed-\ning the capacity of the old system), and a verification system for continuous\nevaluation of SESC forecasts and other forecast models.\nA set of forecast user and operational requirements will be developed for\nSELSIS software to analyze solar images, which is now done manually. Follow-\non phases will develop new solar forecast analysis procedures, using digital\nimage processing such as image subtraction techniques.\nA study will be completed in cooperation with the USAF, and recommenda-\ntions will be made regarding the future of the High-Latitude Monitoring Sta-\ntion at Anchorage, Alaska, which is now jointly operated by the USAF and NOAA.\nDEVELOPMENT\nThe Systems Support Division provides general support to the Space\nSEL\nEnvironment Services Division and to the Research Division in planning,\ndevelopment, and provision of instrument and data systems.\nAccomplishments FY 1985\nOPERATIONAL SATELLITE INSTRUMENTATION\nData from operational Space Environment Monitors (SEM), which are carried\non the NOAA/TIROS and GOES spacecraft, are essential to the operation of the\nSpace Environment Services Center (SESC). The provision of instruments to\n223","replacement spacecraft and the development of new or improvement of existing\ninstruments for spacecraft is, therefore, a very important supporting activi-\nty.\nInstruments are normally produced by contractors ( or subcontractors) to\nNASA, which acts in turn to supply NOAA with the entire operational satellite.\nSEL sets the requirements for the SEM systems and assists with the technical\nsupervision of the instrument contractor. SEL has been asked by NASA to per-\nform recalibration and repair on off-the-shelf instruments awaiting flight and\nalso recently was asked to assemble for the GOES-H program one new instrument,\na High Energy Proton and Alpha Detector (HEPAD), from existing spare parts.\nThis detector provides operational information on radiation hazards caused by\nvery-high-energy solar particles during some solar flare events. The new de-\ntector was substantially completed in FY 1984. After acceptance testing and\ncalibration, the instrument was delivered to the contractor for systems inte-\ngration in January.\nThe existing TIROS instruments awaiting flight were supported as neces-\nsary. Two Medium Energy Proton and Electron Detector (MEPED) units were\nchecked and requalified for flight. Actual repairs were necessary because of\ncomponent failures in one of the MEPEDs and also in the GOES HEPAD.\nThe GOES NEXT program was supported by providing evaluations of the\nbidders' proposals for the SEM system. Unlike previous spinning GOES space-\ncraft, the new satellite will be a three-axis stabilized vehicle. This will\nrequire changes in the design of the SEM instruments, and it will be necessary\nto work closely with NASA and the contractor in the coming year to ensure sat-\nisfactory SEM performance.\nThe effort to provide an operational Solar X-Ray Imager instrument was\nsupported with analysis of the GOES-NEXT contractor's proposal. Off-line\nprocessing of data from the TIROS and GOES spacecraft continued routinely\nduring FY 1985. The major programming effort was to realize the real-time\nprocessing of TIROS and GOES data in the new SELDADS II system.\nSELSIS-SEL SOLAR-IMAGING SYSTEM\nSELSIS will replace the present SESC system that handles solar image data\nin photographic form and transmits by analog wire photo systems. Data will be\nhandled in digital form from the earliest possible stage. The benefits expec-\nted are greatly improved image quality and, most important, the ability to\ncombine image data from more than one source and carry out quantitative image\nprocessing.\nThe overall system will comprise (1) the observatory processors that\ncollect the image data at the various cooperating observatories and make it\navailable for transmissions to Boulder, and (2) the central SELSIS in the\nSESC, which collects and processes the image data, and makes them available to\nthe SESC forecaster. During FY 1985 the design of the observatory processor\nsystem was completed. It is based on standard personal computer hardware and\nadvanced adaptive modem technology for dial-up lines. Observatory processors\nwere installed at the AWS Holloman AFB solar observatory in New Mexico, and at\nKitt Peak National Observatory in Arizona. An observatory processor was also\n224","installed in SESC as a temporary substitute for the more powerful SELSIS sys-\ntem. It permits the forecasters to obtain and view high-resolution digital\nimages from the two observatories, although there is no processing or hard\ncopy capability. During the recent shuttle-launched Spacelab 2 mission, a\ncompatible system was installed at Johnson Space Center in Houston. This\nenabled Spacelab scientists to receive the SELSIS imagery as an aid to\nplanning the pointing of their high-resolution solar-viewing experiments.\nDevelopment of the full SELSIS system, which is based on an advanced\nhigh resolution color workstation, is proceeding. Software for the\ncommunications and for basic image display has been completed.\nDEVELOPMENT OF EXPERT SYSTEMS\nKnowledge-based \"expert systems\" attempt to capture on computer the know-\nledge of a human expert in a limited domain and make this knowledge available\nto a user with less experience. Such systems could be valuable as an assist-\nant to a forecaster or for training purposes. In a pilot project during FY\n1985, SEL collaborated with the Computer Science and Psychology Departments of\nColorado University in Boulder to construct a small expert system emulating a\nmethodology for sunspot classification and solar flare forecasting developed\nin SEL. The project convincingly demonstrated the possibilities of this type\nof computer assistance, which also proved to be a useful tool for formally\nexpressing a methodology and verifying its performance. The system, which has\nbeen named THEO, performed as well as a skilled human forecaster using the\nsame methods, and scored well compared with actual SESC performance in the\nperiod covered by the test data.\nSEL SCIENTIFIC WORKSTATION SYSTEM\nWith the development of high-performance 32-bit microprocessors and high-\nresolution graphics systems, it is now feasible to consider a single work-\nstation for a scientist's desk, to interact with computer systems and display\nscientific data. The local computational capability provides rapid source\ncode editing and debugging, and networking to other workstations and to the\nDOC mainframe scientific computer system which provides the power for major\ncomputations and the capability to return the results for graphical display\nand manipulation.\nDuring FY 1985, three workstations, one with multicolor display and two\nwith monochrome, were delivered and installed for individual users. A fourth,\nSEL\nmulticolorndisplay, workstation will be used for developing image-processing\ntechniques for SELSIS. The workstations are networked with a 12 Mbit/second\ntoken ring system, which permits transparent sharing of the network resources.\nnumber of scientific applications requiring graphical output were success-\nA\nfully transferred to the workstation system and a number of graphic display\ntools were developed.\n225","Plans FY 1986\nOPERATIONAL SATELLITE INSTRUMENTATION\nWe will continue to support the SEM instrument systems on TIROS and the\nexisting GOES series as well as working to ensure that the GOES-NEXT system\nwill meet our needs. A new instrument procurement for TIROS will be initiated.\nThe off-line data processing and data quality control system will be integra-\nted into SELDADS II as this new system is brought into operational use.\nSELSIS-SEL SOLAR-IMAGING SYSTEM\nThe first stage of the development of the SELSIS system will be completed\nand the system installed in SESC. This will permit incoming images to be\nscaled, rotated, and gridded so that the forecaster will have a uniform pre-\nsentation and the capability of accurate position location. SELSIS will also\ninclude a high-quality laser printer system for producing hard copy.\nDEVELOPMENT OF EXPERT SYSTEMS\nWe plan to extend the pilot system to include additional solar data and\nto continue work on verification. We will study other possible applications\nof knowledge-based expert systems to the SESC operation.\nSEL SCIENTIFIC WORKSTATION SYSTEM\nFive more monochrome-display workstations will be added and network\ngateways to the SELDADS II MV10000 computer and to the DOC scientific computer\nsystem will be installed. Software will be made available for preparing\ntechnical documents, and communications from the existing administrative and\nword processing 8-bit microprocessor network will be added.\nRESEARCH\nThe Research Division carries out research in solar-terrestrial rela-\ntions, with the objective of improving our understanding of the effects of\nsolar activity on human activities.\nAccomplishments FY 1985\nSOLAR PHYSICS\nThe objective of the Solar Physics project is to improve medium and long-\nterm solar predictions and to understand the structure and evolution of the\nsolar corona to improve prediction of solar disturbances. During the past\nyear, the activities of the project concentrated on the following:\n226","Expert Systems\nThe group provided the input to the rule base and supported extensive\ntesting and verification of the prototype expert system for solar flare fore-\ncasts. This system is based on the white light sunspot group classification\ndeveloped by this group and on the group's research relating solar flares to\nsunspot structure and evolution.\nSolar X-Ray Imager\nThe installation of operational solar X-ray imagers (SXI) on board the\nGOES-NEXT geosynchronous satellites was a major objective of the Laboratory.\nA singleminstrument concept had been selected that incorporated soft Xoray and\nextreme ultraviolet (EUV) imaging. The SXI, as a part of the Space Environ-\nment Monitor (SEM), will contribute important improvements to predictions of\nproton flares, geomagnetic storms, and real-time EUV heating of the thermo-\nsphere. In a major effort, the Laboratory continued to explore the operation-\nal value of the X-ray imager as a forecasting tool and encouraged its imple-\nmentation on the new GOES series of spacecraft. As a result, the National\nEnvironmental Satellite, Data, and Information Service (NESDIS) proposed an\nFY-1987 initiative for installation of five SXIs on GOES-I through -M and\nNOAA's Office of Oceanic and Atmospheric Research (OAR) proposed an FY-1987\ninitiative for supporting research and technique development. SEL also sought\ninteragency funding for the program. The NOAA-proposed initiative has been\ndeferred to FY-1988 for budgetary reasons, but provision will be made on the\nspacecraft for the SXI to be added as a plug-in option when funding becomes\navailable.\nSolar Maps\nThe ability to prepare solar synoptic maps by computer, facilitated by\nacquisition of the scientific workstation system, has enabled high-resolution\ncolor graphics to be employed in the generation of maps and, more important,\nfor the study of time series of maps. Solar maps for approximately 2 years\nwere entered into the data base for use in the development and testing of com-\nputer programs for display and analysis of solar atmospheric dynamics. Both\ncolor and black-and-white versions of solar maps, with all labels and legends,\ncan be displayed on the workstation screens. Solar maps have led to the in-\ntroduction of a new model for the formation and evolution of sunspots, based\non the fact that sunspots form in preferred locations with respect to the\nlarge-scale patterns of magnetic fields that precede sunspot formation.\nA\nSEL\nthreat to solar mapping is the possible closure of two major observatories\nthat provide solar data-~Mount Wilson and Sacramento Peak.\nSolar X-Ray Studies\nBy use of data from the full-disk, X-ray monitor on the GOES satellites,\na new method was developed for determining flare temperatures and densities as\na function of time. With densities, it is possible to calculate other phys-\n227","ical properties of the flare plasma, such as volume, mass, total thermal\nenergy, gas pressure, radiative loss, and conductive loss.\nSolar Magnetic Structures\nA model of a solar prominence, based on eigenvalue solutions, was con-\nstructed. The model described topologically different magnetic configurations\nwith continuous magnetic field and finite magnetic energy. The thermodynamic\nparameters, including the total mass of a prominence, calculated by the model\nagreed well with observations. The eigenvalue approach has been extended to a\nthreerdimensional model of the solar atmosphere. Force-free electromagnetic\noscillations were proposed as an important physical process in magnetized-\nionized atmospheres. It was proposed also that, during solar flares, force~\nfree electromagnetic solitons are formed.\nSolar Activity\nTo study the evolution and persistence of solar active and inactive lon-\ngitudes, a 14,000-item data base was created covering nearly three sunspot\ncycles (1956 to 1982). A specific objective is to establish whether the\nchange from domination of the solar disk by active longitudes to domination by\ninactive longitudes occurs in a discontinuous manner. A by-product of this\nstudy is information on the asymmetry between the northern and southern solar\nhemispheres, needed for planning the Solar Polar Mission.\nINTERPLANETARY PHYSICS\nThe objective of the Interplanetary Physics Project is to improve fore-\ncasts of the occurrence, duration, and severity of geomagnetic storms through\nthe development of magnetohydrodynamic (MHD) models of the propagation of\nsolar disturbances through the solar wind.\nArrival Times of Flare-Generated Shock Waves\nAn operational \"shock wave\" algorithm was developed in which real-time\nobservations of solar radio bursts, from flares detected by the USAF Radio\nSolar Telescope Network, are input to calculate the time-of-arrival at Earth\nof the shock wave. Impact of the shock wave on the Earth's magnetosphere can\ninitiate a geomagnetic storm when the dynamic pressure of the solar wind and\n(or) the polarity of the interplanetary magnetic field (IMF) are appropriate.\nPropagation of Solar Wind Disturbances\nTwo interplanetary models have been developed: a 2%-dimensional (21/2-D)\nmodel confined to the ecliptic plane, and a fully threendimensional (3-D)\nmodel. The 21/2-D model was transferred to SEL's scientific workstation system\nand provides a cost-effective tool for two purposes: (1) sensitivity tests for\nsolar input parameters and (2) a test-bed for operational usage. The 3-D\n228","model, designed for eventual input of solar X-ray images, was tested on a\nCRAY-1 computer. The models provide geoeffective parameters such as solar\nwind dynamic pressure, solar wind power, and the IMF polarity, all of which\nare crucial diagnostics for predictive capability.\nSolar-Terrestrial Environment Model\nWith the collaboration of external scientists and the Department of\nDefense, a strategy was developed that holds promise for tracking disturbances\nfrom the Sun to the auroral ionosphere and thermosphere. A composite model\nwas devised that inputs photospheric data into a 2-D chromospheric and coronal\nmodel and whose output serves as input to a 1-D interplanetary model. The\noutput of the latter model provides the starting point at the Earth's magneto-\nsphere for the propagation of a disturbance through the magnetosphere to the\n300-km level of the auroral atmosphere. This permits calculation of the tem-\nporal profile of energy input to the thermosphere, which indicates possible\natmospheric density increases by a factor of 10. The energy deposited into\nthe auroral ionosphere agrees with that required to account for the short-time\n(minutes) increases in the ultraviolet intensities observed by the Dynamics\nExplorer satellites. The neutral density increase at 300 km, over several\nhours, is sufficient to explain observed satellite drag.\nMulti-Fluid Solar Wind Studies\nTo improve the existing models of the solar wind, two changes were\nintroduced: (1) The spatial scales over which the magnetic field in the solar\nwind can change polarity were reduced to 10 5 km. (2) The importance given\nto\nmultiHfluid structure protons and electrons) was increased. The change\nallows short-time-scale processes caused by non-neutrality and results in\ncoupling by means of electric fields. The results will be combined with\nearlier work that incorporates realistic dissipative effects such as thermal\nconductivity, temperature anistropies, and non*Maxwellian energy distributions.\nThe use of small spatial scales in the interplanetary models will result in\nmore accurate prediction of IMF polarity changes and, therefore, more accurate\npredictions of the coupling of energy between the solar wind and the magneto-\nsphere.\nMAGNETOSPHERIC PHYSICS\nThe objective of the Magnetospheric Physics Project is an improved under-\nstanding of the dynamical processes by which material and energy are transpor-\nSEL\nted from the solar wind into the magnetosphere, stored, and eventually dis-\nsipated in the Earth's ionosphere. Both applications and research are pursued\nto improve the quality and utility of the Laboratory's products and services.\nPolar Cap Studies\nThe Earth's magnetic field restricts the direct entry of charged ener-\ngetic particles. Low-energy protons can reach the Earth's atmosphere only in\nthe polar regions, whereas higher energy protons can reach the Earth at lower\n229","latitudes. Energetic protons from solar cosmic ray events represent a radi-\nation hazard to space activities and high-altitude aircraft. A preliminary\ncomputer procedure was developed that identifies the (polar cap) entry region\nfor solar cosmic rays. The size of the entry region is a function of particle\nenergy, geomagnetic disturbance conditions, and local time.\nData Support\nProcedures for the analysis of GOES particle data were entirely re-evalu-\nated, and the resulting recommended procedures were incorporated into algo-\nrithms that are being included in the SELDADS II real-time data system. With\nthe new procedures, data interpretation is simpler and more consistent.\nThe computer codes for the off-line processing of the NOAA/TIROS particle\ndata were rewritten. The original codes had evolved in an ad-hoc fashion, and\nhad become unwieldy. The new codes are well designed and efficient. Trial\nimplementation and debugging are near completion.\nGOES magnetometer data were analyzed with respect to the nightside\ntopology of the geomagnetic field at geostationary orbit. Some short-lead-\ntime predictive capability is possible in that the field becomes more\ntailAlike in the < 20Hmin interval prior to a geomagnetic substorm. However,\nthis capability is of limited use because it represents a necessary but not\nsufficient condition for ensuing activity.\nExternal Cooperation\nBoth data and consultation support continue to be provided to the Defense\nNuclear Agency (DNA) for the conduct of its Long Wave Program to study\nionospheric propagation of low-frequency signals. A data distribution system,\nfor use with a personal computer, was initiated for easy exchange of satellite\nparticle data in as near a universal and friendly format as possible.\nCooperative studies concern the Theta Aurora, first observed by imaging\ninstruments aboard the Dynamics Explorer satellites; data correlation, in\nconjunction with the Middle Atmosphere Program (MAP) ; and plasma theory.\nNumerical Studies\nEarlier theoretical studies of plasma phenomena in the magnetosphere\nrelied on MHD approximation to ensure tractable equations. It has become\nclear that important physics have, thereby, been neglected. Therefore, new\nemphasis was placed upon computer plasma simulations in magnetospheric\nstudies.\nSimulation studies of particle behavior in an x-type magnetic neutral\npoint configuration, like that expected to occur in the geomagnetic tail, were\nundertaken to establish the role of this magnetic configuration in the accel-\neration of particles. As a point of departure, initial calculations had\nconfirmed the successful tail acceleration mechanism previously proposed by\nSEL scientists. Experimental study has identified this region of the\n230","magnetosphere as being important for the transfer of electromagnetic energy to\nthe particle populations, which subsequently modify the properties of the\nionosphere.\nStudy continued on magnetic reconnection, through which energy is coupled\nfrom the interplanetary medium to the magnetospheric system, and also on the\nwave-particle interactions that the magnetospheric plasma populations undergo\nin energy transfer processes.\nATMOSPHERE-IONOSPHERE-MAGNETOSPHERE INTERACTIONS\nThe objectives of this project are an improved understanding of the\ntransfer of electrical and mechanical energy from the Earth's magnetosphere\ninto the upper atmosphere, and a characterization of the possible consequences\nof this input in the Earth's ionosphere and upper atmosphere.\nData Acquisition\nObservations from instruments on board the TIROS/NOAA-6 and -7 spacecraft\ncontinued to be obtained, processed, and used in both research and as a quan-\ntitative measure of geophysical activity. Because of the aging of the detec-\ntors, the quality and amount of these observations degraded during the year.\nEarly in CY 1985, spacecraft operational difficulties often reduced the flow\nof data from a normal 95% to less than 40% Tracking of NOAA-7 ended as\nNOAA-9 (without a space environment monitor) came into operation. The net\nresult is that the amount of data now acquired is about 40% of that a year\nago, and the quality has deteriorated somewhat.\nData Studies\nSeveral studies were carried out using the NOAA/TIROS total energy data.\nFor example, a study was made of the symmetry, or conjugacy, of the energy\ninput to the atmosphere occurring simultaneously in the Northern and Southern\nHemispheres. Data from NOAA/TIROS and the Defense Meteorological Satellite\nProgram show that considerable symmetry exists in the energy input over the\nequatorward and center portions of the auroral precipitation regions. This\nsymmetry breaks down in high (polar cap) latitudes where the energy input into\none hemisphere may bear little resemblance to that in the other hemisphere.\nA\nsecond example is a study of energetic particle precipitation in latitudes\nequatorward of the auroral zone, using data from NOAA/TIROS and the Stimulated\nSEL\nEmissions of Energetic Particles experiment. This study showed that precipi-\ntation may be short lived but can extend over large distances. There is a\npossibility that the precipitation is triggered by lightning strokes and that\na single stroke affects the energetic particle population over a wide region\nSO that tropospheric phenomena may exert a significant control over the inner\nmagnetosphere. A third example is participation in the Global Thermospheric\nModeling Study, a project directed toward the detailed analysis of the\nbehavior of the Earth's upper atmosphere during three selected periods in 1984.\nData from the NOAA/TIROS detectors were used to characterize the degree of\ngeophysical disturbance (power input) and also provide information on the\nenergy input ( on an hour~by-hour basis) as a driving input to the models. The\n231","use of the power input as a measure of geophysical disturbance is gaining\nacceptance in the scientific community.\nIonospheric Conductivity Maps\nThe total energy deposition data base was used to construct maps of the\nelectrical conductivities of the ionosphere in the polar regions. Constructed\nfor different levels of auroral activity, the maps use the same activity\nparameters as those used to construct the patterns of particle energy influx,\nviz., hemispheric power input. The maps are important because the major\nsource of heat to the auroral upper atmosphere is the heat generated by cur-\nrents flowing in a resistive ionosphere. A combination of conductivity maps\nwith patterns of electric fields, together with energy input by the particles\nthemselves, allows the total heat input to be determined. This leads to a\nbetter assessment of the magnitudes of the perturbations resulting from the\nheating.\nCorrelation Studies\nA correlation study was performed between the estimated hemispherical\npower input activity, the conventional magnetic activity indices, and param-\neters of the interplanetary medium that are thought to control geophysical\nactivity. Correlation was good (coefficient approximately 0.75) between the\npower input and magnetic indices, but it had a large variance. This suggests\nthat the two parameters may be measuring different aspects of geophysical\nactivity and/or that neither is a good measure of activity. Furthermore, an\nassociation between power input and the interplanetary magnetic field showed\nreasonable agreement as, for example, with the north-south component of the\nIMF, but again the variance was large, suggesting the absence of cause-and-\neffect relationship.\nOperational Aspects\nIn addition to their use in the above studies, TIROS data were made\navailable for operational purposes. For example, an extensive data set,\nconcerning the very largest energy fluxes, was made available to the Jet\nPropulsion Laboratory for the purpose of specifying the particle environment\nthat will be encountered by polar-orbiting shuttles.\nPlans FY 1986\nSOLAR PHYSICS\nDevelop expert systems for application of research results to solar-\nterrestrial prediction services; conduct further testing of THEO against\nobserved activity, persistence, and forecasters, and test performance\nwith different users.\n232","Establish a solar data base management system to assure a supply of high-\nquality solar observations through contracts with established observa-\ntories and contracts for enhancement of a solar data base through scaling\nand statistical studies.\nEnter archives of solar synoptic charts into a digital data base accessed\nby a staterof-the-art graphics computer. Develop graphics displays that\nfacilitate analysis of relationships between large-scale aspects of solar\nactivity and the occurrence of solar sources of geophysical disturbances.\nSolar X-Ray Imager\nParticipate in preparation of two FY -1988 initiatives for hardware (with\nNESDIS) and for supporting research (OAR).\nFurther develop operational uses of X-ray images using prototype images\nfrom Skylab. Establish a limited SEL data base for image analysis and\nmanipulation.\nPrepare a plan for realizing SXI operational utility in conjunction with\nduty forecasters and researchers. This will involve technical and scien-\ntific assistance in SXI design, fabrication, and performance testing and\nthe outlining of suitable calibrations, operating modes, and algorithms\nnecessary to bring the SXI to operational use immediately after launch.\nPrepare a priority plan for future SXI research tasks such as verifica-\ntion procedures, new X-ray flare classification schemes, application of\nrecent Solar Maximum Mission flare results, and other science goals.\nINTERPLANETARY PHYSICS\nEvaluate the sensitivity of MHD model predictions of travel time of solar\ndisturbances and predictions of the bulk solar wind parameters at Earth,\nwith respect to uncertainties in input parameters.\nMake quantitative assessment of the value of measurements of solar wind\nparameters, using the scintillation of radio stars, for use in empirical\nand quantitative forecasting models of the transmission of solar disturbo\nance energy to Earth.\nExtend the three-dimensional model to include a simple heliospheric\nSEL\ncurrent sheet and coronal hole configurations. The model will be\ntransferred to the CYBER 855/205 computer in Gaithersburg.\nReduce grid size by half in the 21/2D model, to study finer spatial and\ntemporal structure in the solar wind.\nFurther develop the strategy for a solar-terrestrial environment model.\nStudy multi-fluid, electrified plasmas to assess the importance of strong\nelectric fields and small-scale structures in the solar wind.\n233","MAGNETOSPHERIC PHYSICS\nDetermine an empirical relationship between geomagnetic activity and the\ncutoff latitudes of solar cosmic rays. This operational relationship\nwill be used to estimate the geographical extent of radiation hazards and\nradio communication disruptions.\nProvide support to assure the quality of real-time and non-real-time data\nand data processing.\nBegin use of WAVE plasma simulation routines to study phenomenology of\nthe magnetosphere boundary.\nComplete a data processing system (energetic particles) for use with a\npersonal computer.\nStudy effects of magnetic field merging in the magnetosphere.\nATMOSPHERE-IONOSPHERE-MAGNETOSPHERE INTERACTIONS\nEstablish disturbed ionospheric conductivity patterns as a function of\nthe geophysical activity parameter, using the particle energy patterns\nfrom the NOAA/TIROS total energy detector data.\nProcess data from the NOAA/TIROS total energy detector and distribute.\nUse the NOAA/TIROS particle data as input to a thermospheric dynamical\nmodel to calculate changes in temperature, density, and composition as a\nfunction of energy input.\n234","COOPERATIVE INSTITUTES\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nSEL\nWPL\nARL\nAL\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nSeveral Environmental Research Laboratories interact with the university\ncommunity through cooperative institutes. These institutes provide a mecha-\nnism for research collaboration and training in areas of mutual interest to\nNOAA and the academic community. There are six of these institutes at uni-\nversities in Colorado, Washington, Hawaii, Oklahoma, and Florida; each is\nclosely associated with one or more of NOAA's Environmental Research Labora-\ntories.\nCIMAS\nThe Cooperative Institute for Marine and Atmospheric Studies (CIMAS) is\nan association between NOAA and the University of Miami's Rosenstiel School of\nMarine and Atmospheric Science (RSMAS) to stimulate cooperative research\nbetween the institutions. The three research themes of CIMAS are Climate Vari-\nability, Ecosystem Dynamics, and Ocean-Sea Floor Hydrothermal Interactions.\nThe primary CIMAS staff consists of nine Fellows who are appointed from\nRSMAS faculty and NOAA's laboratories in Miami and who conduct collaborative\nresearch. Also included in the staff during FY 1985 were six Members, three\nCIMAS\nAssociate Scientists, six Research Associates, four Postdoctoral Associates,\nand four graduate students. Members of the staff conduct research at the\nCIMAS building, the RSMAS campus, and NOAA laboratories. CIMAS also conducts\nresearch through partial support of visiting collaborating scientists who aug-\nment the expertise at RSMAS and NOAA. During FY 1985 the visiting scientists\nprovided more than 8 man-months of collaborative research and 33 lectures.\n235","Accomplishments FY 1985\nCLIMATE VARIABILITY\nResearch on climate variability concerned Subtropical Atlantic Climate\nStudies (STACS), Equatorial Pacific Ocean Climate Studies (EPOCS), and atmos-\npheric carbon dioxide (CO2) loading.\nBoth theoretical models and field measurements indicate the Florida\nStraits as a critical monitoring point for determining the northward transport\nof mass and heat in the North Atlantic. A CIMAS research effort in support of\nSTACS is directed toward understanding the effects of local forcing by the\ncurl of the wind stress over the Gulf of Mexico and Caribbean Sea on the trans-\nport at the Florida Straits and the implications this might have on the inter-\npretation of the routes by which heat is transported northward by the ocean.\nInvestigations were prompted by the strong correlation (0.95) between the\ntransport at the straits and the cycle of the wind stress curl over the\nCaribbean--particularly over the Cayman basin (the straits lagging the basin\nby 6 days).\nA linear barotropic flat bottom model reproduced the spin-up time scale\nand suggested that there should be inflow through the Windward Passage in\nphase with the forcing. Examination of the tide gauge data at Guantanamo Bay,\nCuba, and Port Au Prince, Haiti, confirmed this hypothesis. What has been\nparticularly rewarding, however, is the introduction of bottom topography in\nthe form of geostrophic contours (i.e., f/h contours, where f is the Coriolis\nforce and h is the fluid depth). There is a nexus in these contours at the\nFlorida Straits. Contours on the eastern side of the straits encircle the\nBahamas Bank and are closed. On the western side of the straits the contours\nare blocked to the south. Since the barotropic signal propagates along f/h\ncontours, the response on the western side of the straits is sensitized to the\nforcing along the boundary--including the coast of the Gulf of Mexico, the\ncoast of the Caribbean Sea, and the coast of South America as far south as 6°N.\nFurthermore, because of the nexus in the f/h contours at the Florida Straits,\nthe forcing to the south will influence the pressure distribution around the\nBahamas Bank. The seasonal response of the transport at the Florida Straits\nis forced by the curl of the wind stress over the Cayman basin. The geostro\nphic contours extend uninterrupted from the Gulf of Mexico through the Cayman\nbasin. The curl of the wind stress forces a barotropic boundary layer\nresponse into the Gulf of Mexico. Because of the character of the geostrophic\ncontours at the western end of Cuba, any return flow is blocked and the signal\npropagates to the Florida Straits.\nHeat is transported from the tropical Atlantic into the Caribbean princi-\npally along the northern coast of South America. One of the principal mechan-\nisms driving the flow is an along-shore pressure gradient built up in response\nto the upwelling along the coast. Along the coast, the Ekman transport is\noffshore causing the upwelling. Though the interior transport is onshore, it\nis not strong enough to compensate for the offshore Ekman transport. Since\nthe bottom slope effectively shuts off the contribution by the bottom Ekman\nlayer, continuity requires the interior transport to be supplemented by an\nonshore geostrophic flow. On the average, then, there is an increase in the\npressure along f/h contours northward, toward the Florida Straits. This pres-\nsure gradient on the average turns the Sverdrup transport to the north toward\n236","the Florida Straits, and its modulation contributes to the mass flux through\nthe eastern Caribbean and hence contributes to the heat transport.\nThe other major Atlantic research effort consists of (1) analysis of\nfield data from current meters, Pegasus ocean velocity profiler, tide gauges,\ntelephone cables, and other instrumentation used in the Florida Current compon-\nents of the STACS experiment, and (2) field experiments, including several\ncruises, to study surface and deep currents in the southern part of the Gulf\nStream recirculation region, including the Deep Western Boundary Current\n(DWBC).\nAnalysis of the Florida Current data progressed to the point where an\nintegrated picture can be formed of the mean and perturbation flow parameters\n(mean velocity, temperature and density fields, heat perturbation and momentum\nfluxes, etc.) across the Florida Current at 27°N, the location of the major\nfield experiment. Enough statistics on flow fluctuations were obtained to\ndetermine how a reduced set of measurements (in particular, cable measure-\nments, but also subsets of Pegasus profilers or current meters) could be used\nfor long-term monitoring of Florida Current transport. In addition, some in-\nteresting local effects in the Florida Current due to its interaction with\nlocal topography are under analysis.\nThe area of research on the transport of mass and heat in the Florida\nCurrent/Gulf Stream system was extended northward, using a 3-year series of\nPegasus absolute velocity and temperature sections taken in the Gulf Stream\nnortheast of Cape Hatteras and similar measurements taken in the Florida Cur-\nrent. The time-averaged data sets from the three cross-stream locations (27 o,\n29° and 36°N) were used to examine the transport of the current by depth and\ntemperature layers. After the sections were aligned, a \"velocity anomaly\"\nover the cross sections was computed by least-squares minimization of the\ntemperature fields, to further examine transport fluctuations.\nField work was extended to the region of the North Atlantic Ocean north-\neast of the Bahamas, to study both the recirculation of the Gulf Stream sur-\nface flow and to make, for the first time, a more detailed study of the DWBC.\nThis joint effort included two NOAA vessel cruises as well as one cruise by a\nRSMAS vessel. During the latter cruise, deep (to 4 km) absolute velocity pro-\nfiles of the DWBC were obtained for the first time, using Pegasus. Prelimi-\nnary results suggest that the DWBC is much wider and extends much higher up\ninto the water column than had previously been thought.\nPacific Ocean research in support of EPOCS consisted of analysis of drift-\ning buoy and tritium data.\nSeveral analyses were completed on some aspects of the satellite-tracked\nCIMAS\ndrifting buoy data collected by the EPOCS program. Intensive analysis of the\nstructure and energetics of mesoscale eddies associated with the cusp-shaped\nlong waves commonly observed in sea surface temperature patterns of the east-\nern equatorial Pacific was completed. All the data collected prior to the El\nNiño event of 1982-83 were used to generate a monthly climatology of surface\ncurrents in the eastern tropical Pacific. This climatology was used to com-\npute the rate of equatorial upwelling from the divergence of near-surface curm\nrent, which is the first estimate of equatorial upwelling with the associated\nerror base.\n237","Local and Lagrangian heating in the Eastern Tropical Pacific Ocean was\nthe subject of intensified research. The evolution of sea surface temperature\nand current fields before, during, and after the El Niño event of 1982-83 was\ninvestigated using the data from satellite-tracked drifting buoys. Local and\nnet heating and the zonal and meridional advective import/export were computed\nseparately from the buoy data, and vertical advection of heat was estimated as\na residue. Assuming that heat exchanges are confined to a 50-m thick mixed\nlayer, clear annual cycles of both local and net heating, with amplitudes of\nabout 70 Wm- and 80 Wm-2 respectively, were found in the region 0°-10°S,\n90°-130°W. Seasonal heating anomalies of up to about 40 Wm- were found\nduring both normal and El Niño periods. The major event in the net heating\nanomaly series is a long period of strong net anomalous cooling from early\n1982 through 1983. A strong zonal advective heating is clearly seen during\nthe El Niño period from the winter of 1981 through the fall of 1983; a brief\nanomalous cooling occurred in the winter of 1982. An intense downwelling,\nwhich also seems to have an important role in the 1982-83 event, is found from\nmid-1982 through early 1983.\nTidal currents in the eastern equatorial Pacific were investigated by\napplying modal decomposition to the current meter records obtained from 10\nlevels near the Equator at 110°W to separate the barotropic (surface) and baro-\nclinic (internal) tides. The barotropic tide shows a reasonable agreement\nwith the existing numerical global modals of the M2 tide. It was found that\nmost baroclinic energy is confined to the upper ocean, for both east and north\nvelocity components. The baroclinic energy could be accounted for by the\nstrong density stratification and related to the slope of the thermocline in\nthe equatorial Pacific. Seasonal variability shows that baroclinic tide is\nstronger in the winter than in the summer.\nIsopycnal advection in the mean wind-driven circulation was found to be\nthe dominant process for the penetration of tritium from high northern lati\ntudes into the tropical Pacific. The tritium data show that there is a closed\ndecadal-time-scale meridional circulation extending from high northern lati-\ntudes to the Equator above 26.8 sigma-theta. Thus the North Pacific thermo-\ncline is ventilated to the Equator on decadal time scales. The tritium data\nwere shown to be in large part consonant with the recently developed\nventilated-thermocline theory.\nThere is a prominent signature of equatorial upwelling in the tritium\nfield. This signature provides unique insights and conclusions about equato-\nrial upwelling. Tritium data provide a means of separating the role of advec-\ntion of cool Southern Hemisphere water from that of upwelling in the mainten-\nance of the equatorial \"cool tongue\". Tritium data showed that the upwelling\noccurs above the 26.2 sigma-theta surface. The tritium data also showed that\nthere is substantial zonal variability in the upwelling, a maximum occurring\nbetween 120°W and 150°W.\nResearch on the relation between atmospheric CO 2 loading and climate con-\nsisted of modeling deep ocean chemical cycling and making ocean measurements\nby cyclosonde and radar imagery in the Marginal Ice Zone Experiment (MIZEX).\nIn the geologic record, one of the most striking indicators of different\noceanic climate states is the existence of layers of black organic-rich deep-\n238","sea sediments indicative of widespread anoxia. A simple coupled model of the\nocean's carbon, oxygen, and phosphate (COP) system was developed to study the\noccurrence of anoxia. Recent isotopic measurements in ice cores indicate that\natmospheric CO2 changes may have occurred on several-hundred-year time scales,\nwhich suggests that CO 2 variations may have played a role in the forcing of\nthe glacial-Holocene climate transition. A time-dependent version of the COP\nmodel shows that these CO 2 variations could be forced by perturbations in the\nmarine carbon cycle.\nDuring MIZEX in the summer of 1985 more than 1,100 cyclesonde vertical\nprofiles of temperature, electrical conductivity, and velocity were recorded\nin the Fram Straits from drifting ice floes tracked by Argos transmitters.\nInstruments were deployed from the R/V Polar Queen and its helicopters. In\naddition one cyclesonde recorded downwelling, light intensity, and light\ntransmission.\nThe MIZEX work in FY 1985 concentrated on the analysis of the 1983 and\n1984 field data. Preliminary results show strong vertical gradients in temper-\nature, salinity, and velocity in the upper 200 m of the ocean under the ice.\nThese gradients are modulated by tidal/inertial period motions together with\nstrong wind event responses. The light transmission data show a highly repeat-\nable vertical; maximum light absorption occurs near the surface and in a thin\nlayer located between 35 and 55 m depth. The deeper maximum in light absorp-\ntion coincides with a maximum in phytoplankton concentration, and there is\nsome indication of coincident oxygen maximum. These data indicate that pri-\nmary productivity in the marginal ice zone may be greater than previously\nsupposed.\nAnalysis of radar imagery of the Arctic pack ice and marginal ice zone\nwas initiated. This consisted of organizing the imagery and construction of\noverlays of the flight tracks. The initial emphasis was placed on the 6 July\nperiod when surface windstress measurements were obtained by the Bedford Insti-\ntute of Oceanography. A preliminary comparison of observed and model drag\ncoefficients indicated that the surface measurements are somewhat high. This\nmay be due to the local nature of the measurement in comparison with the in-\ntegrated result obtained by a moving aircraft. Further examination of these\nresults requires computer processing of the imagery on a small scale.\nAnother aspect of the imagery is the strong enhancement of ridges and\nrough structure as a result of the high incidence angles of the low-altitude\nimagery. Although the radar look-angles were low enough to limit shadowing,\nthe shallow grazing angles resulted in very high returns from ridges within a\nfloe and from the fractured regions between floes. It thus appears that a\nroughness index based upon these returns can be established and compared with\nroughness indices obtained from the laser altimeter. As heat and momentum\nCIMAS\ntransfer are a function of the roughness and thickness of the ice, these data\nmay result in refinements of the classification of ice types.\nECOSYSTEM DYNAMICS\nUnderstanding the causal mechanisms of fish stock variability is the pri-\nmary objective of CIMAS ecosystem dynamics research. Efforts are focused in\ntwo areas: (1) the early life history stages, and survival and dispersion\n239","caused by physical, chemical, and biological oceanic processes, and (2) the\neffects of fishery exploitation on tropical and subtropical ecosystems.\nThe abundance of bluefin tuna larvae spawned in the Gulf of Mexico in\n1982 and 1983 was estimated after the South East Area Monitoring and Assess-\nment Program (SEAMAP) ichthyoplankton data base for those two years had been\nedited. From these estimates and previous ones for 1977, 1978, and 1981,\nfishery-independent estimates were made of spawning stock biomass and popula-\ntion size for western North Atlantic bluefin tuna. These estimates indicate\nthat spawning stock has declined since 1978. An indication that spawning in-\ncreased slightly in 1983 is tentative, since the Gulf of Mexico sampling grid\nwas not completed because of bad weather. The larval data frequency followed\na delta distribution. The non-zero larval catches were log-normally distrib-\nuted, so unbiased minimum variance estimates of mean catch and its variance\ncould be made. The derived confidence intervals were proportionally narrower\nwith this method than with other methods in general use.\nAdditional larval fish research consisted of completing the SEAMAP data\nbase for serranids (groupers), beginning analysis of the serranid data, and\ncompleting a larval drift model study. The last was applied to anchovy larvae\nto determine the advection by the ocean processes of geostrophic and wind-\ndriven currents to 50 m depth and turbulent diffusion. It was found that the\npeak time of spawning (March) coincided with the minimum period of advection.\nAn initial study of a multispecies reef fish assemblage was completed.\nData from the Puerto Rican reef fish fishery were used to parameterize a multi-\nspecies simulation model. The model was employed to determine the effects of\nexploitation, and management strategies and state-of-the-art assessment tech-\nniques. Preliminary results for the tropical reef fish assemblage, i.e., with-\nout consideration of interspecies interactions, indicated that management\nstrategies must take into account the relative species mix in the catch and\nthat the consequences of not doing so could have long-term effects. Under\nvery restrictive assumptions, state-of-the-art assessment techniques can be\nused. However, the restrictive nature of the assumptions indicates a strong\nneed for the development of new assessment methods.\nUnderstanding the biological processes associated with larval fish survi-\nval requires the development and application of innovative sampling technolo~\ngies for the zooplankton communities of which the larval fishes are a part.\nIn a new research project, the major task of the first few months was com-\npleted--a 2-week Gulf Stream cruise on the R/V Cape Florida. Equipment was\nalso designed and built; testing included three separate days of sea trials of\nthe plankton camera system on R/V Calanus.\nThe objectives of the first cruise were (1) the proving of new equipment\ndesigns, (2) intercomparison of plankton sampling/mapping techniques, (3)\ndetermining fine-scale distribution of the zooplankton of the upper 100 m of\nthe water column, (4) documenting the evolution of populations in the Gulf\nStream, and (5) observing the changes across the western Gulf Stream front.\nThe Doppler acoustical instrument and computer hardware successfully operated\nthroughout the cruise. Data were obtained from 22 deployments of plankton\ncameras and 10 deployments of multiple opening/closing net environmental sens-\ning systems (MOCNESS). Deployments were done back to back with 26 multi-\nfrequency acoustic plankton surveys (MFPS) They took place both night and\n240","day, and included two 24-h cycles in the Gulf Stream, and two transects across\nthe front off Cape Canaveral. Two cross-stream XBT surveys (30-nm tracks) for\nstream flow computations were completed, and several submarine photometer pro-\nfiles were made. Live MOCNESS samples were silhouette-photographed on board,\nand live copepods were collected and processed for gut fluorescence studies.\nWork on chemical oceanic properties continued with research and develop-\nment of methods for the identification and determination of oxidized organo-\nsulfur species in the marine environment. The gas chromatographic techniques\nfor doing so have been refined. Previously unreported dimethylsulfoxide and\ndimethylsulfone had been identified in rain samples collected over the equato-\nrial Pacific. The concentrations of these compounds are typically 1-10 ug/l.\nThese oxidized sulfur compounds are formed by the oxidation of biogenic\ndimethylsulfide in the boundary layer.\nOCEAN SEA-FLOOR HYDROTHERMAL INTERACTIONS\nThis research theme was approved for CIMAS during FY 1984. Planning\nefforts for the modeling and measurement of the physical dynamics of sea floor\nvent plumes continued through FY 1985.\nPlans FY 1986\nCLIMATE VARIABILITY\nResearch on ocean-related aspects of climate will continue in FY 1986 in\nsupport of STACS, EPOCS, and the CO2 loading problem. Atmospheric research\nsupporting EPOCS will be undertaken as a new effort.\nThe local forcing project will examine in more detail the effect of the\nnexus in the f/h contours at the Florida Straits since this nexus implies that\nthe pressure distribution around the Bahamas Bank is influenced by the forcing\nalong the boundary to the south. As the northward geostrophic flow through\nthe straits increases, the mean pressure around the bank should increase in\nphase. Consequently, on the North Atlantic side one might expect to observe\nan offshore pressure gradient set up to oppose the formation of an Antilles\ncurrent. There are two points here: (1) Because of the topography, the re-\nsponse should be trapped near the boundary, and (2) because the response is\nbarotropic, its effect should be felt throughout the water column. It need\nnot be strong enough to reverse any shallow Antilles current; it need merely\nmake it more diffuse. And since it is barotropic, it may serve to accelerate\nthe deep western boundary current. This latter point is especially interest-\nCIMAS\ning for it may mean that the northward seasonal transport at the Florida\nStraits is compensated primarily by a southward seasonal transport in the deep\nwestern boundary current. If this is true (and current meter measurements do\nsuggest that the deep western boundary current has a seasonal component), the\nseasonal component of the heat transport could be considerably larger than has\nbeen estimated in the past.\nFurther analysis and modeling of the Florida Current, based on STACS data\nset, will be undertaken. An important part of this work will include efforts\n241","to predict the time-variable temperature field (and thus the \"heat flux\") from\ncable (or other) transport data and a limited number of temperature measure-\nments. Analysis of cruise data obtained last year in the Gulf Stream recircu-\nlation region and the DWBC will proceed. Several additional research cruises\nto the DWBC/recirculation region will be conducted.\nIn the continuation of the moored-current-mete data analysis, a trans-\nport series will be derived from the STACS VI array (June 1984-June 1985),\nwhich had a much-reduced set of instruments compared with the previous arrays.\nTherefore, besides direct transport calculations, regressions with Pegasus and\ncable data will be used. The larger scale variability and its relation to\nwind forcing will be studied by merging the STACS data with those from FACTS\nmoorings. Jointly, the data cover a stretch of about 500 km of the Florida\nCurrent and a period close to 2 years.\nA new field program with three moorings east of the Bahamas was initiated\nwith AOML. Moorings will be deployed in April by the R/V Researcher for 1\nyear. Possible extensions of the field program include moored acoustic\nDoppler profilers and reciprocal acoustic transmissions.\nThe northern segment of the Florida Current/Gulf Stream transport study\nwill be completed. The associated analysis of the Antilles Current data will\nbegin. Efforts will be made to include additional hydrographic measurements\nin future cruises. Such measurements will allow examination of the Pegasus\nabsolute velocity data in the context of the larger-scale dynamic height\nfield.\nWork on the EPOCS drifting buoy data will continue with research on tech-\nniques of process analyses. Emphasis will be placed on the largest space\nscales and annual and interannual time scales.\nIn support of EPOCS, analysis of the existing Global Climate Monitoring\n(GCM) data archived at the National Center for Atmospheric Research (NCAR)\nwill begin in order to investigate possible mechanisms for the maintenance of\ntropical Pacific sea surface temperature (SST) anomalies. History tapes from\nseveral model runs already completed will be used to compute, for the equato-\nrial Pacific, the patterns of sensible heat flux, radiative heat flux, evapora-\ntion, and wind stress. These patterns will be compared with the prescribed\nSST anomaly that was used for each experiment. The objective is to see\nwhether these atmospheric forcing patterns are such as to promote a tendency\nfor the SST anomaly to increase, to decay, or to move. In addition, a search\nfor the 30-60 day oscillation in the tropical Pacific will be conducted for\nour GCM runs. If such an oscillation is present, its structural character-\nistics will be documented, and an attempt will be made to determine the origin\nof this oscillation in the GCM.\nResearch associated with the CO 2 loading problem will continue with\nhierarchical modeling, cyclosonde measurements, and radar imagery. The latter\ntwo efforts will continue in association with MIZEX.\n242","ECOSYSTEM DYNAMICS\nPlanned research on larval fish includes (1) a continuation of analysis\nof bluefin larval abundance with respect to oceanographic conditions, to\ndevelop a better understanding of the ecological correlates of spawning and\nlarval survival, and subsequent fluctuations in adult stocks; (2) a critical\nreview of the literature to assess the relative importance of environment,\npredation, and competition on the survival of larval fishes; and (3) the\ndevelopment of sampling strategies for coral reef fish larvae.\nZooplankton sampling technology application research will begin the\nanalysis phase, including an integration with material provided by colleagues.\nExperimentation will begin with a digitizing system for inputting data\ndirectly to a microcomputer, which may eventually help to automate at least\nthe proximal examination of MOCNESS silhouette data, and perhaps eventually\nthe plankton camera data. Two cruises will be conducted during 1986.\nFisheries dynamics research will be expanded to examine the responses of\na broader set of communities. New research to develop assessment techniques\nfor tropical and subtropical ecosystems will be undertaken.\nThe main feature of the chemical process research planned for FY 1986 is\na research cruise in the tropical Atlantic. Detailed boundary layer vertical\nprofiles of volatile organic compounds, ozone, and ancillary data will be\nobtained. Volatile organics will be analyzed using a new gas chromatograph/\nmass spectrometer system.\nOCEAN SEA-FLOOR HYDROTHERMAL INTERACTIONS\nResearch will focus on initial modeling of the physical dynamics of the\nconvective plumes of sea floor hydrothermal vents. Planning will concentrate\non a field program to make field measurements of the model's parameters and to\ninvestigate the biological processes associated with the vent field.\nCIMMS\nThe Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) is\na joint venture of the University of Oklahoma (OU), ERL, and NOAA through the\nNational Severe Storms Laboratory (NSSL). CIMMS received first funding in\nlate FY 1978 and began major efforts during FY 1979. The program objectives\nand activities of CIMMS complement and supplement those of NSSL and the\nUniversity through research conducted by Visiting Fellows, NOAA, University\nCIMMS\nstaff, and student appointees. The present council of Fellows, which helps\nformulate policy, includes two members from NSSL, both of whom hold adjunct\nprofessional appointments at OU, and three members from OU. The Advisory\nCouncil, which includes representative from OU, NO AA, and outside organiza-\ntions, meets annually.\nCIMMS is addressing several research issues important to NOAA/ERL. Pro-\ngrams will lead to improved observation and forecasting of meteorological\n243","systems at the mesoscale down to the microscale. These systems produce most\nof our local weather but currently are not well understood. The potential\neconomic and social benefits of accurate observation and prediction of severe\nstorms, winds, and precipitation are immense.\nCIMMS can most effectively address its scientific goals with a small,\ncore scientific staff augmented by a temporary scientific staff of Post-\ndoctoral Fellows. The Postdoctoral Fellows (both new graduates and experi-\nenced scientists) are appointed for up to two years. These individuals are\nselected on the basis of demonstrated research ability in the needed theme\nproject areas. A small permanent scientific staff is required to assure con-\ntinuity of research programs. This staff is drawn from the University of\nOklahoma, NOAA, and full-time research scientists. Both OU and NOAA provide\nimportant basic support for CIMMS, but neither directly funds the research\ndone by the permanent CIMMS staff. Such additional support is derived from\ngrants and contracts.\nAccomplishments FY 1985\nDuring 1985, CIMMS was host to researchers from China, Taiwan, Japan, and\nFrance, who undertook studies in mesoscale meteorological modeling and develop-\nment of optimization analysis in Doppler radar meteorology. A CIMMS research\nscientist has continued his work on the Alpine Experiment (ALPEX) and satel-\nlite-based analysis techniques. In October 1985 he will travel to Venice,\nItaly, to attend the First Conference on the Results of ALPEX. A research\nscientist received a grant from NSF to study extended theories of conditional\nsymmetric instability and their application to problems associated with\nfrontal rainbands. Another research scientist, also supported by an NSF\ngrant, is working on turbulence statistics in laboratory-simulated tornado\nvortices. His group is obtaining a high-caliber flow visualization device\ncapable of resolving fine structures in the flow trajectories, thus providing\nturbulent velocity correlation statistics useful in obtaining the frictional\nforce in theoretical studies. A high-resolution 3-D numerical model is being\ndeveloped in an attempt to simulate the turbulent flow. Laboratory flow\nmeasurements will serve as a check for verification of the model. Two Post-\ndoctoral Fellows on multiyear appointments work in mesoscale modeling and con-\nvective instability. Fourteen graduate students employed by CIMMS are engaged\nin research studies that may lead to advanced degrees.\nCIMMS research results were reported in nine reports and five publica-\ntions during FY 1985.\nIn October 1985, CIMMS will be host to the International Symposium on\nVariational Methods in Geosciences.\nPlans FY 1986\nThe main objective of CIMMS cooperative research efforts is to develop\nadvanced and automated weather nowcasting and forecasting technology, or more\nspecifically to provide techniques leading to reliable diagnosis and predic-\n244","tion of paralyzing severe weather at the mesoscale--flash floods, heavy snow-\nfall, gusty winds, poor visibility, and icing; and tornadoes, hail, and\nlightning.\nThrough these research efforts CIMMS will continue to address the follow-\ning research themes:\nMesoscale modeling. Develop models that include mesoscale initialization\nand assimilation of new input data, parameterization of diabatic\nprocesses, and terrain-influenced boundary layers. The goals are to\ndevelop mesoscale models that are physically sound and practically useful\nfor analysis and prediction of mesoscale weather phenomena in a 0-36 h\ntime frame.\nMesodynamics. Investigate symmetric and shearing convective\ninstabilities to reveal mechanisms of initiation, development, and decay\nof severe weather. The ultimate goal is to improve physics in mesoscale\ndiagnostic and prognostic models.\nOrography and lee cyclogenesis. Discover mechanisms of boundary layer\nformation, separation, and diurnal variation; develop a more realistic\nand predictable terrain-influenced boundary layer parameterization for\nmesoscale models; develop an understanding of how these phenomena lead to\ncyclogenesis.\nVariational optimization analysis. Develop efficient and accurate\ntechniques for analysis of remotely sensed data including Doppler radar\nand Profiler observations, which promise to be important for diagnosing\nhazardous mesoscale severe weather and which may provide initialization\nand assimilation data for diagnostic and prognostic mesoscale models.\nCIRA\nThe Cooperative Institute for Research in the Atmosphere (CIRA), estab-\nlished September 1980, is jointly sponsored by Colorado State University (CSU)\nand NOAA, and has close relationships with ERL in Boulder and NESDIS in\nSuitland, Md.\nThe Institute's research has concentrated on global climate dynamics,\nlocal-area weather forecasting, severe storms, and the application to climate\nstudies of satellite observations. In addition, the Institute and National\nPark Service cooperate in air quality research. CIRA is playing a major role\nin the NOAA-coordinated U.S. participation in the International Satellite\nCloud Climatology Project (part of the World Climate Research Program).\nCIRA\nFive NOAA/NESDIS scientists in residence at CSU constitute the Regional\nand Mesoscale Meteorology Branch of the NESDIS Satellite Applications Labora-\ntory. They lead the CIRA collaboration with ERL in short-range weather fore-\ncasting research.\n245","The CSU departments engaged in CIRA research are Atmospheric Science,\nStatistics, Psychology, Civil Engineering, Electrical Engineering, and Recrea-\ntion Resources. Currently 24 separate research projects have been funded\nthrough CIRA, including an IPA (Intergovernmental Personnel Act) Fellow with\nthe National Weather Service. CIRA personnel consist of 14 Fellows, 4 Visit-\ning Fellows, 11 Research Associates, 2 Visiting Scientists, a Deputy Director,\nand a Director. During FY 1985, six Graduate Research Assistants received\ndegrees--three M.S. and three Ph.D Each year the Visiting Fellows Program\nprovides the opportunity for independent research at CSU in collaboration with\nselected NOAA scientists. A \"co-op\" program allows CSU graduate students to\nwork in residence at NOAA Laboratories.\nCIRA was host to a WMO-sponsored workshop entitled \"Cloud Top Boundary\nLayer\", on 22-26 April 1985. Twenty-seven scientists from throughout the\nworld participated. In coordination with NASA-Goddard Space Flight Center,\nCIRA was host to NASA personnel for a week during July 1985. Their visit in-\nvolved interaction with many of the faculty and research personnel at the\nDepartment of Atmospheric Science and CIRA.\nPlans include continued collaboration of NOAA and CSU scientists and\nstudents in research related to NOAA's mission within the special themes of\nCIRA, expansion of the Visiting Fellows Program, and continued development of\nresearch involving NOAA and CSU scientists with other agencies.\nA workshop on \"Acid Deposition in Colorado-- Potential or Current\nProblem; Local Versus Long-Distance Transport Into the State\" is planned for\n1986. This workshop will facilitate interaction among participants from\nseveral departments of CSU.\nCIRES\nThe Cooperative Institute for Research in Environmental Sciences (CIRES)\nis jointly sponsored by the University of Colorado and NOAA and receives a\nroughly equivalent amount of support from other public and private sources.\nCIRES Fellows have academic affiliations with eight departments at the Univer-\nsity of Colorado: Chemistry, Chemical Engineering, Physics, Geography, Geolog-\nical Sciences, Electrical Engineering, Mechanical Engineering, and Astro-\nphysical, Planetary and Atmospheric Sciences. Current research in CIRES is in\nfour broad areas: Environmental Chemistry, Atmospheric Dynamics, Climate Dynam-\nics, and Solid Earth Geophysics.\nENVIRONMENTAL CHEMISTRY\nThe areas of research include environmental analysis, reaction kinetics,\nmolecular biology, surface science, and analytical instrumentation. Environ-\nmental applications include such diverse subjects as acid rain, air and water\npollution associated with energy development, climate change resulting from\ncarbon dioxide emissions from fossil fuel burning and other pollutants, strato-\nspheric ozone depletion, improvements in catalyst technology, fuel additives\n246","to improve efficiency of combustion and decrease pollutant emissions, photo-\nchemical oxidant formation in the troposphere, use of microorganisms to de-4\ntoxify chemical waste, earthquake hazard evaluation based on gaseous emissions\nfrom the ground, protection of crops against frost, marine measurements of\nchlorofluoromethanes as transient tracers of ocean circulation and global up-\ntake of pollutants by the sea, and evaluation of the atmospheric consequences\nof nuclear warfare.\nAccomplishments FY 1985\nCIRES research in environmental chemistry contributes to important NOAA\nprograms in acid rain, radiatively important trace species, and global atmos-\npheric chemistry, as highlighted below.\nIt is known that both natural and anthropogenic chemical species can\nmodify deposition. Even if emission of the latter were reduced, natural\nsources would continue to contribute to deposition. Thus, the anticipation of\nbenefits from controlled reduction of a compound could be erroneously optimis-\ntic if natural sources made a significant contribution to the total budget of\nthe compound. In particular, natural emissions of sulfur-containing compounds\nfrom biogenic sources provide the irreducible minimum background for sulfuric\nacid, which is the principal acid deposited in the eastern United States. An\nunderstanding of the natural component of this sulfate deposition requires an\nunderstanding of the biological processes responsible for the natural sulfur\nemissions. Work in progress is aimed at elucidating the biogeochemical\ncycling of sulfur in relation to the biogenic emission of sulfur gases. This\nresearch focuses on the origin of methylated sulfur species such as\nmethanethiol, dimethylsulfide, and dimethyldisulfide. Little is known concern-\ning the mechanism(s) and physiological regulation involved in the production\nof these species. The release of dimethylsulfide as a major sulfur compound\nin the atmosphere has been attributed to its formation and release from vegeta-\ntion and aquatic algae. Our recent results indicate that another important\nsource of this sulfur gas is microbial methylation of hydrogen sulfide.\nVarious bacteria isolated from soil, water, and plant surfaces were found to\nexhibit high cellular activity for the methylation of exogenous hydrogen sul-\nfide, emitting a mixture of methanethiol and dimethylsulfide. All these\nisolates were shown to contain relatively high levels of an enzyme, thiol\nmethyltransferase, that carries out the methylation of sulfide. The same\nenzyme was shown to catalyze the methylation of methanethiol, yielding\ndimethylsulfide. In addition, the same enzyme catalyzes the methylation of\nhydrogen selenide. Thus these bacteria also have the capability of emission\nof methylated selenium gases. These results have important implications for\ninterpreting field measurement data on the flux of biogenic sulfur gases from\nsoil and vegetation.\nCIRES\nNew analytical techniques to measure trace gases in the atmosphere are\nneeded to support continued progress toward unraveling the complexities of the\nchemistry of the troposphere and stratosphere. Work under way at CIRES and\nthe Aeronomy Laboratory is aimed at the development of surface conversion tech-\nniques to be used as detectors for important atmospheric trace gases. One\nsuch effort involves the use of a gold catalyst to cause the reduction of\nreactive nitrogen oxide compounds, NO y, to NO, a compound that can be sensi-\n247","tively detected. During the past year, Laboratory capabilities were developed\nfor detailed studies of the chemisorption and reaction of gases on solid sur-\nfaces. It is now possible to obtain vibrational spectra of adsorbed molecules\non well-defined, single-crystal surfaces in order to determine molecular struc-\nture and chemical bonding. Most work is focused on studies to elucidate the\ncatalytic reaction mechanism of NO y reduction in atmospheric detection instru-\nments that use a gold catalyst.\nIn addition, new detectors for high-performance chromatography based on\nchemiluminescent reactions were developed. Of particular relevance to environ-\nmental chemistry is the development of a sulfurtselective detector for High\nPerformance Liquid Chromatography having low picogram detection limits. This\ndetector had earlier been developed and applied to gas chromatography. With\nthis new capability the sulfur selection detector can now be used to analyze\nliquid and liquidrextracted samples.\nWork is also progressing on research aimed at understanding the chemistry\nand spectroscopy of atmospheric trace compounds and radicals. Flow tube\nkinetics methods were used to study reactions important in regulating the\nquantity and distribution of ozone in the stratosphere. The rate constants\nfor the reactions\n0 + NO 2\nNO + 0 2\n0 + C10 C1 + 0\nwere measured over the temperature range 220-387 K. These reactions are the\nrate-determining steps for the NOX and C10 X catalytic cycles, which largely\ncontrol the concentration of ozone in the stratosphere.\nThe ultraviolet absorption spectrum and the stratospheric reactions of\nthe HOC1 molecule were also investigated. These studies were made possible by\nthe development of a new dynamic source for the generation of HOCI having very\nlow impurities of the interfering species C120. Absolute absorption cross\nsections were obtained in the wavelength range 240-390 nm, and rate constants\nfor reactions of HOC1 with OH and H were determined. The product branching\nratio in the reaction with HOC1 with C1 was also measured.\nIn addition to the research efforts that are being carried out in CIRES\nlaboratories, CIRES research associates and assistants are collaborating with\nscientists from the ERL on a variety of programs in Boulder and elsewhere,\nincluding measurement of the global budget of CO2, methane, and ozone; study\nof the arctic haze; measurement of natural emissions that contribute to atmos-\npheric acidity and alkalinity; investigation of processes involved in acid\ndeposition, the ropospheric/stratospheric exchange processes, and kinetics of\ntropospheric and stratospheric reactions.\nPlans FY 1986\nThe programs described above are ongoing and will continue. Other program\nareas will contribute important new capabilities to CIRES basic research.\nGas chromatography (GC) and liquid chromatography (LC) utilizing mass\nspectrometric (MS) detection are used for trace compound identification and\n248","analysis in a wide variety of applications. The sensitivity and/or specific-\nity of these instruments is often determined by the method used to ionize the\nanalyte compound in the mass spectrometer. In CIRES, GC-MS and LC-MS instru-\nments are now operational, employing laser multiphoton ionization as the ion-\nization/fragmentation method. Techniques have been developed to use these\ninstruments for trace metal speciation and organic molecular analysis. The\ndetection method is selective toward compounds that absorb radiation at wave-\nlengths 260 nm or greater. These instruments will be used to obtain laser4\ninduced fluorescence and/or multiphoton ionization spectra of molecules.\nOther potential applications include the analysis of environmental samples\n(liquid or gaseous) and the study of unimolecular photochemical reactions.\nThe rate constant and product distribution of the reaction between C10\nand BrO radicals will be measured as a function of temperature. This reaction\ncould participate in a significant cycle for ozone depletion in the\nstratosphere:\nC1 + Br + O2 2\nC10 + BrO\nC1 + 03 3\nC10 + 0 2\nBr + 0 3\nBrO + 0 2\nNet: 2 0 3\n3 0 2\nOther atmospheric reactions to be studied include those of S2 2 with 0 2 0 3, and\nNO 2° S2 2 is occasionally injected into the stratosphere by volcanic eruptions.\nATMOSPHERIC AND CLIMATE DYNAMICS\nAtmospheric and Climate Dynamics (ACD) research at CIRES encompasses a\nbroad spectrum of theoretical, experimental, and observational investigations.\nThis is reflected in the fact that ACD personnel actively collaborate with ERL\nscientists in five different Laboratories. In addition, research is conducted\nwith funding by various other Federal, state, and private agencies. Interac-\ntions among investigators from the various projects have fostered a fertile\nworking environment that often leads to unexpected and gratifying results.\nMuch of the CIRES/ACD research takes place as part of ERL programs\ndescribed by the Laboratories:\nResearch on the dynamics of the solar corona and the interactions of the\nsolar wind with the Earth's magnetosphere, at SEL.\nResearch on the remote sensing of the middle atmosphere and the\nCIRES\ninteractions of upper atmospheric chemistry and dynamics, at AL.\nResearch on the changing amounts of atmospheric trace chemical\nspecies and volcanic dust, at ARL.\nResearch on atmospheric remote sounding, influences of topography on\nweather, and techniques for prediction of aircraft icing, at WPL.\n249","Research on the climatology, morphology, and predictability of the\nlarge-scale climatological phenomenon known as the Southern\n0scillation/El Niño, at ESG/Climate Research Program.\nOther funding for CIRES/ACD research is derived from NSF, NASA, DOE, DOD,\nand other, smaller, sources. For convenience, this work can be subdivided\ninto three categories: atmosphere-ocean interaction, cryosphere-climate inter-\naction, and interactions of waves and turbulence with mean flows. As the\ntitles suggest, ACD research is mainly concerned with the interactions among\nthe various media and component processes of the Earth's climate system on\nvirtually all scales of time and space. The following Accomplishments and\nPlans pertain to this interdisciplinary research.\nAccomplishments FY 1985\nATMOSPHERE-OCEAN INTERACTION\nBecause of its small thermal and mechanical inertia, the atmospheric com-\nponent of the Earth's climate system, the weather, responds relatively quickly\nto changes in boundary conditions. The atmosphere's lower boundary condition,\nhowever, is largely determined by the temperature of the sea surface, which,\nowing to the much larger inertia of the oceans, behaves with very different\ntime and space scales. The interaction of atmosphere and ocean at the sea\nsurface is therefore a multiple-scale problem of considerable importance to\nunderstanding climate. CIRES/ACD research into air-sea interaction includes\ntheoretical and observational work on the boundary layers on each side of the\ninterface and their interactive physics.\nIn FY 1985, a series of field experiments, in collaboration with ERL and\nNASA scientists using a NOAA/OAO P-3 research aircraft, was performed to\ninvestigate the radiative and dynamical interactions within the marine strato-\ncumulus cloud deck that is a dramatic climatological feature of the Pacific\noff the coast of California. This is a particularly interesting climatic\nregime because the clouds' existence significantly reduces the solar energy\nabsorbed by the underlying ocean, and there is reason to believe that the\npresence of the clouds is determined in part by low surface temperatures. The\nresearch missions in FY 1985 were performed as a contribution to the First\nRegional Experiment of the International Satellite Cloud Climatology Project\nin support of a multi-platform, multi-agency field program to occur during FY\n1987.\nThe mechanisms that connect the atmospheric boundary layer to the underly-\ning ocean, i.e., the processes that move heat, moisture, and momentum between\nthe media, have been and continue to be studied in detail using sampling tech-\nniques developed by CIRES researchers. Experimental data from very-fast-\nresponse turbulence measurement systems (the NOAA/ERL gust probe system and\nthe NCAR system) were analyzed with conditional sampling, which uses thresh-\nolds to determine significant events, and with bivariate analysis, which uses\njoint frequency distributions, to examine the mechanics of various categories\nof plumes that carry sea-surface properties to the atmosphere and redistribute\nheat, moisture, and momentum within the atmospheric boundary layer. Evidence\n250","is beginning to accumulate that these discrete events are not only dominant\nover continuous, isotropic turbulence but may also be used as tracers. This\nwill increase understanding of atmospheric turbulence for a wide variety of\nconditions.\nOn the other side of the air-sea interface, CIRES/ACD research has invest-\nigated the feasibility of including in an adiabatic flow model of the large-\nscale ocean dynamics the nonadiabatic processes associated with atmosphere-\nocean interaction. In collaboration with University of Miami (Fla.) scient-\nists, an isopycnal model of the ocean dynamics (that is, a model in which\npotential density is anindependentopseudo-vertical-coordinate was general-\nized to include a mixed-layer model of the oceanic boundary layer that takes\naccount of the solar heating and turbulent fluxes of latent and sensible heat\nat the ocean surface. This new development in ocean circulation modeling will\nallow the numerical advantages of the adiabatic flow properties of the\ninterior ocean, particularly those associated with the ability to resolve re-\ngions of large density gradients without special numerical methods, to be\nexploited in the study of climatic aspects of atmosphere-ocean interaction.\nIt will also allow the development of truly interactive modeling of the\nprocesses at the sea surface and the way these processes affect the deep\nocean.\nCRYOSPHERE-CLIMATE INTERACTION\nOn longer time scales the climate is affected by and controls the changes\nin the Earth's ice sheets, sea ice, and glaciers. The amount of water locked\nin the Antarctic ice sheets alone is equivalent to some 54 m of global sea\nlevel, and the presence or absence of ice caps is an important factor in the\nEarth's energy balance. The possibility that instabilities in glacial\ndynamics can exist has prompted a strong interest in glacial ice-stream flow\nstudies in recent years. Research at CIRES has centered on modeling the dynam-\nics of the West Antarctic ice sheet, one of the continent's largest. Dynam-\nical models of the ice streams have been extended to include processes associ-\nated with basal friction and hydraulics, features that had been previously\nneglected. Included in these studies are climatic-forcing scenarios such as\nthe probable changes in the atmosphere due to the carbon-dioxideninduced\n\"greenhouse\" and the ice sheets' response.\nCIRES also houses the World Data Center A for Glaciology [Snow and Ice]\nand the associated National Snow and Ice Data Center. During FY 1985 these\ncenters' responsibilities were extended to include the newly developed Cryo-\nspheric Data Management System (CDMS). A dedicated computer system and rele-\nvant software were acquired for the purpose of archiving and servicing data\nfrom the special sensor microwave imagery system on the Defense Meteorological\nSatellite Program (DMSP) satellites. Of particular interest to climate\nresearchers will be the capability of snow/cloud discrimination with the satel-\nCIRES\nlite data. Since snow cover, particularly snow that does not melt during the\nsummer, is very important in climate dynamics, this capability will provide a\nnew tool for monitoring climate change. Analysis of these data is facilitated\nby the newly acquired image analysis system that is mated to the CDMS com-\nputers. Work began on several projects using the DMSP imagery: Frequency of\nArctic cloudiness was determined for April-June 1979 and 1980 and is being\ncompared with existing climatologies and statistics generated by a numerical\n251","general circulation model; surface melt of Arctic ice was mapped; and lake\nfreezerup/break-up data for Finland and Canada were shown to agree with fall\nand spring temperature records.\nINTERACTION OF WAVES AND TURBULENCE WITH MEAN FLOWS\nThe processes by which small-scale turbulent motion interacts with larger\nscale dynamics are relevant to studies of both atmosphere and ocean. In addi-\ntion, interactions of waves with flows that can be considered to be a larger-\nscale mean environment are also important features in scale interaction in\nfluids. The best-known example of the latter process is the absorption of\nwave energy in mean flow \"critical layers\" wherein the wave group speed\nmatches the flow rate. Turbulence/mean-flow interaction is lessHwell studied,\nbut research at CIRES/ACD is beginning to indicate that analogous processes\nmay occur.\nExperimental studies using the WPL Boulder Atmospheric Observatory, a\n300-m instrumented tower, were conducted to examine the fine structure of\nstatically stable atmospheric layers. These studies showed a small-scale\nsheet-and-layer structure in both temperature and humidity to exist that had\nnot been observed in the atmosphere but had been reported to occur in the\nocean's thermoclines and in density gradients in lakes and estuaries. This\nstructure has strong implications for electromagnetic wave propagation and\nwill need to be taken into account in future modeling studies of the stable\nboundary layer.\nModeling studies of wave/mean-flow interaction in the middle atmosphere\nwere aimed at understanding dissipation processes and the transport of nitric\noxide. This transport is important in trying to determine the processes in-\nvolved in the winter anomaly, an event in which an increase in radio wave\nabsorption is observed. Preliminary results of the model indicate that plane-\ntary waves and auroral activity are necessary to provide the required trans-\nport of nitric oxide out of the polar regions and into the middle latitudes.\nExperimental work was done using Doppler radars in the equatorial middle atmos-\nphere. An experiment, at the Jicamarca, Peru, observatory was designed to\nmeasure the neutral winds in order to examine the diurnal tide. This tide is\nbelieved to be important in providing frictional drag in the equatorial middle\natmosphere.\nPlans FY 1986\nATMOSPHERE-OCEAN INTERACTION\nExperimental work on the atmospheric boundary layer will continue with\nCIRES scientists' participation in the forthcoming Frontal Air-Sea Interaction\nExperiment (FASINEX) in February and in the subsequent data analysis. FASINEX\nis a multi-agency field program to investigate the atmospheric and oceanic\nprocesses on each side of the subtropical Atlantic (ocean) front; in addition\nto the NOAA/OAO P-3 used by the CIRES researchers, the field plan includes\nfive other research aircraft and two research ships; extensive satellite data\nanalysis will take place during and after the field phase. In support of\n252","FASINEX, the hybrid ocean model discussed above will be used to simulate the\nfrontal dynamics and changes in air-sea interaction across the front.\nThe extensive marine stratocumulus cloud data set obtained during the FY-\n1985 missions will be analyzed in detail with several objectives. These in-\nclude the examination of the influences of the diurnal cycle on the dynamics\nof the cloud deck, for which purpose early+morning and late-afternoon missions\nwere flown; one of the least-known aspects of cloud dynamics is the effect of\nvariable radiative forcing on the cloud, and these data will lend insight into\nthose processes. The field program was coordinated with dedicated retrievals\nof LANDSAT Thematic Mapper images of the cloud deck (with nominal resolution\nof 30 m), and an important aspect of the data analysis will be comparison of\nthe radiative properties of the clouds as observed by the aircraft and the\nsatellite. These high-resolution platforms will be compared with the GOES\noperational data that were recorded routinely. Although interactions of cloud\ndynamics and radiative transfer are relatively obscure, it is known that the\nstratocumulushtopped boundary layer represents a case of strong interaction.\nThe conditional sampling of gust probe data will be extended to this case, and\nresults compared with the more canonical cases analyzed previously. This\nshould provide fundamental insight into very basic aspects of boundary-layer\ntheory, including a new perspective on the scaling quantities.\nCRYOSPHERE-CLIMATE INTERACTION\nTwo aspects of the glacial surge studies will be pursued. The modeling\nstudies will be crossvalidated with data from glacial monitoring for a vari-\nety of locations, and the models improved on that basis. In addition, other\nmodeling assumptions will be tested using the data set to be assembled. The\nmajor new initiative will involve a combined field/modeling study of the\nJakobshavens ice stream in Greenland. Airborne (helicopter) sampling of the\nsaline properties of the outflow fjord will establish the rate of basal melt-\ning, and this will be compared with model predictions. During the sampling\nmissions, photographic surveys will record changes in the thickness and the\nflow rate of the ice.\nIt is expected that the suite of analytic instruments associated with the\nCDMS project will be expanded with the acquisition of an automated digitizing\nsystem. This device will be used to re-digitize selected parts of the exten-\nsive DMSP film archive housed at CIRES at nearly the original resolution, and\nhence allow construction of climatological data bases on Arctic sea ice and\nclouds. When combined with the power of the image analysis system, it will\nalso provide a means of integrating previously incompatible data formats. The\nability to perform data services for the Data Centers' customers will be in-\ncreased markedly. In-house analyses to occur during FY 1986 include compari-\nsons of DMSPminferred Arctic melt progression with that observed by the\nNimbus-7 passive microwave system, and comparisons of Antarctic sea ice extent\nCIRES\nand sea surface temperatures with atmospheric trends in carbon dioxide at\nSouthern Hemisphere stations.\n253","INTERACTION OF WAVES AND TURBULENCE WITH MEAN FLOWS\nThe analysis of the fine-structure observations will be completed with\nemphasis on explaining the occurrence of layering and the spacing between the\nsheets and layers. This will include hultiple-regression/partial-correlation\nanalyses of the mean gradient and the turbulence quantities to examine the\nimplications for atmospheric diffusion. The roles of Kelvin-Helmholtz instabi-\nlity and gravity waves in creating the fine structure will be studied, and\nfurther implications for wave propagation will be explored.\nAn outgrowth of the ESG/Climate Research Program investigations concern-\ning the development of extratropical waves in relation to convective episodes\nin the tropics will be explored. The case study will use GOES sounder data\nthat, serendipitously, captured a wave development episode that seems to be\nrelated to deep convective forcing in the central equatorial Pacific. The\nwave subsequently propagated eastward and brought significant weather to the\nU.S. Gulf Coast. The study to be initiated will begin the investigation of\nthe predictability of such weather events, based on wave development in the\nPacific.\nThe investigation of the winter anomaly will continue. In addition,\nanother modeling effort will begin on the interaction of stationary and trans-\nient planetary waves and their coupling between the troposphere and strato-\nsphere. The data obtained from the Jicamarca experiment will be analyzed for\nthe winds. Other experiments are being planned for studying large-scale atmos-\npheric waves. One such experiment involves the hardware and software design\nof a portable system that can be attached to existing radar systems.\nThe interactions between large-scale (quasi-geostrophic) waves in the\nstratosphere and the mean zonal flow will be studied with a numerical model.\nIn particular, the effects of transient versus stationary forcing of the wave\non the wave's structure will be examined to determine the role of frequency of\nthe forcing and the resultant wave amplitudes. This will lead to insight into\nthe role of transient forcing in the structure of resonant traveling waves and\nthe stratospheric mean flow.\nSOLID-EARTH GEOPHYSICS\nAccomplishments FY 1985\nSolid-earth geophysics continues to be a major theme of CIRES research,\nalthough support for the program is obtained predominantly from outside\nNOAA/ERL (e.g., USGS, NSF, NASA, DOD). Some of the CIRES research on geodesy\nis now supported by the National Geodetic Survey. The NOAA-National Geo-\nphysical Data Center also provides support and an important point of interac-\ntion between CIRES and NOAA scientists.\nThe current program concerns whole-earth geodesy, geodynamics, laboratory\nstudies of rock failure and rock properties under high stresses, earthquake\nprediction and other observational seismology, theoretical studies of wave\ngeneration and propagation, and engineering seismology.\n254","The geodynamics program has used a variety of modern techniques to invest-\nigate local and regional deformation of the crust. Current research, funded\nby and of importance to the National Geodetic Survey includes two- and three-\ncolor laser electronic distance measurement instruments (which are being used\nto measure crustal movement in southern California); theoretical and observa-\ntional studies of variations in the rotation of the Earth, Earth and ocean\ntides, and other large-scale motions within the Earth.\nResearch directed to understanding local and regional crustal deformation\nis based on (1) high=precision measurements of changes in the length of lines\nseveral kilometers long that monitor tilts of the crust, and (2) the develop-\nment and use of NASA-sponsored extraterrestrial geodetic techniques using\nlaser ranging to satellites and radio interferometric observations of natural\nor artificial radio sources in space.\nRecently the University Navstar Consortium was awarded $1.5 million to\nbegin the assembly and testing of satellite geodetic terminals. The terminals\nwill make use of the Navstar Global Positioning System (GPS) satellites. The\nprincipal investigator of the project is in CIRES. One of the important\naspects of GPS geodesy is correction for path delay resulting from tropo-\nspheric water vapor. The use of microwave water vapor radiometers (WVRs) is\nbeing investigated with recent funding from USGS. A follow-up GPS test was\nconducted in the spring of 1985 by the consortium and a number of other\nagencies. The resulting data set is now under analysis, including corrections\nfor ionospheric, tropospheric, orbit, and phase ambiguity resolution errors.\nObservational seismology is directed to the investigation of dynamic\nEarth processes and Earth structure on the basis of the data from seismograms\nof earthquakes or other seismic sources. Earthquake prediction research pro-\nvided a focus for much of the work in observational seismology in the past\nyear; seismotectonic studies offered a closely related second focus. In the\nsearch for approaches to earthquake prediction we are currently studying\nseismicity patterns, focal mechanisms, seismic wave velocities, crustal defor-\nmations, average magnitudes of earthquake sets, stress drops, wave attenua-\ntion, and the chemistry of soil gas. We have shown that some of these observ-\nables have changed before past major earthquakes.\nThe theoretical seismology program, which is largely supported by DOD as\npart of its nuclear test-monitoring research program, has resulted in the\ndevelopment of powerful computer codes for calculating synthetic seismograms\nand new approaches to source interpretation based on the analysis of very-high-\nfrequency seismic waves.\nA major theme of experimental and theoretical studies is seismic velocity\nanisotropy. A recently completed study, supported by NSF, yielded a pattern\nof anisotropy in the upper mantle beneath Tonga and Fiji that can be related\nto flow patterns associated with major plate movements. The laboratory rock\nCIRES\nphysics group has developed new models of upper mantle mineralogy that\naccounts well for many observed properties, including anisotropy.\nThe engineering seismology program, funded by NSF, has included studies\nof surface motion amplification due to topographic features and alluvial\nvalleys, and investigation of dynamic response of extended underground struc-\n255","tures like pipelines and tunnels. Work has continued also in wave dispersion\nand attenuation in media with microstructures, e.g., cracks, voids,\ninclusions.\nThe present efforts of the rock physics group are directed to gaining\nbetter understanding of the dependence of rock deformation and fracture on\ntime and ambient conditions. This work is motivated by the desire to eluci-\ndate such diverse phenomena as the evolution of planetary crusts, earthquake\nmechanisms and precursors, and problems associated with the disposal of hazard-\nous waste materials.\nThe group recently embarked on a challenging experimental approach to\ngaining an understanding of the stresses within the mantle that drive tectonic\nplates. The attenuation of seismic waves in the mantle seems to be due to\ndislocations within mantle crystals. The equilibrium dislocation density is a\nfunction of the stress within the mantle. The experimental approach will be\nto measure the attenuation of elastic waves in the seismic frequency band as a\nfunction of dislocation density. The experiments will have to be performed\nwith the sample at temperatures in excess of 1000 °C. Parallel with the experi-\nmental effort there will be theoretical studies of the seismic anisotropy of\nEarth's crust and mantle. As results from seismology are combined with those\nof solid state physics, an understanding of the physics of flow of the mantle\nis emerging.\nPlans FY 1986\nWe are extending current models of the Earth's rotational motion (nuta-\ntions, variations in rotation rate, etc.) to compare with the rapidly improv~\ning observations in an attempt to learn about the Earth's deep interior. We\nare modeling deformation of the Earth's surface caused by nontectonic proces-\nses, such as atmosphere and oceanic forcing, so that its effects can be re-\nmoved from high-quality geodetic data.\nFor FY 1986, the form of support for the Central Aleutian seismic network\nprovided by the U.S. Geological Survey (USGS) will change to a cooperative\nagreement, rather than a contract. Network operations and earthquake catalog\npreparation will continue. The prediction research effort, with USGS support,\nwill concentrate on the analysis of physical parameters along the main fault\nzone under the Central Aleutian Islands and the application of fracture mech-\nanics theory to the interpretation of time-varying stress patterns.\nWork on precursors to Hawaiian earthquakes will continue.\nSome work has been initiated in the area of ultrasonic nondestructive\nevaluation of composite plates. This is a combined and theoretical study of\nwave propagation and scattering in layered anisotropic plates. Funding for\nthis work is being actively sought from NSF, ONR and ARO. Recent developments\nof a high-frequency, absolute displacement transducer will allow precise ultra-\nsonic signed measurements. Work is also in progress in phase transformations\nin ceramic materials under stress and in the nondestructive evaluation of\nfailure progression in concrete.\n256","Work in the engineering seismology area is now directed toward wave propa-\ngation and amplification in layered media. Also under investigation is the\ndynamic response of structures embedded in layered media.\nJIMAR\nThe Joint Institute for Marine and Atmospheric Research (JIMAR) is\nlocated at the University of Hawaii. JIMAR was formed in FY 1978 in associa-\ntion with the University and PMEL. The principal research interests of JIMAR\nare climate, equatorial oceanography, and tsunamis.\nAccomplishments FY 1985\nCLIMATE RESEARCH\nJIMAR's climate research in FY 1985 included studies of interactions\nbetween middle- latitude and tropical circulation, Pacific island rawinsonde\nprofiles, and surface wind fields derived from surface and satellite data.\nComposites of middle-latitude dropwindsonde data collected near tropical\neast Pacific cirrus surges during the Global Weather Experiment (Special\nObserving Period-1) were analyzed. The analyses indicated that surges were\ncaused by equatorward-penetrating middle-latitude systems. Cross sections of\nindividual events agreed with the composites. We confirmed a published com-\nposite model that linked Asian winter monsoon activity with synoptic develop-\nments in the Hawaiian region.\nEmpirical orthogonal function analysis showed an inverse relationship\nbetween large-scale convective activity over the Australian monsoon region and\nthe Society Islands. Spectral analysis indicates that systems with 20-40 day\nperiods account for the inverse relationship.\nPacific island station rawinsondes for 1971-1976 were also examined.\nPower spectrum analysis of zonal winds showed 15-30 day oscillations in the\nmidtroposphere for the 1972-1973 El Niño. In the upper troposphere 30-60 day\nmodes were insignificant during El Niño but appeared significant during pre-\nand post-El Niño periods.\nThe meshed data from ships, buoys, small islands, and atolls, and derived\nsurface winds from low-level satellite winds were analyzed and grid point data\nextracted through March 1983 for the Pacific Ocean. Owing to the extreme wind\nanomalies during the 1982483 ENSO, our normal method of using climatological\nshear to derive surface winds from satellite data was modified for the period\nJIMAR\nNovember 1982 through May 1983. Subjective analysis and evaluation of the\nComprehensive Ocean-Atmosphere Data Set (COADS) revealed many instances of\nsuspect and/or misplaced data. The COADS data have proved sufficient for a\nvery reasonable wind analysis over most areas of all three oceans. The COADS\npressure data permit a subjective analysis of the atmospheric pressure at sea\nlevel, which is in good agreement with the winds.\n257","EQUATORIAL OCEANOGRAPHY\nJIMAR's equatorial oceanography activities in FY 1985 included new obser-\nvational efforts with the Line Islands Array and Western Equatorial Pacific\nOcean Circulation Study (WEPOCS), data analysis of NORPAX and PEQUOD data\nsets, and theoretical studies. Several sea level networks, data centers, and\nprojects also continued.\nIn February and March 1985 inverted echo sounders and shallow subsurface\npressure gauges were installed in the equatorial central Pacific using the R/V\nMachias. The Line Islands Array consists of these instruments in combination\nwith island tide gauges. This array will be maintained for 5 years to study\nsynoptic oscillations in sea level and their relation to wind and current fluc-\ntuations. Sixty-two hydrographic stations were occupied on two meridional\nsections throughout the array.\nWEPOCS field work started in June 1985. Large-scale hydrographic surveys\nwere conducted, and five shallow subsurface pressure gauges were deployed\nfrom the R/V Thompson in the Solomon and Bismarck seas. Pegasus current pro-\nfiles at six sites along 150°E were carried out aboard the Australian R/V\nFranklin. An Acoustic Doppler Current Profiling program began on the R/V\nMoana Wave and R/V Franklin. Near-surface relative current profiles were made\non both WEPOCS cruises and on an equatorial transit aboard the R/V Moana\nWave.\nAnalysis of NORPAX and PEQUOD data continued, using more than 500 Pegasus\nprofiles taken during the Line Islands Profiling Project. Studies of the\nstructure of the deep equatorial jets indicated that the jets did not propag-\nate vertically during the 16-month period of these observations.\nEvent detection methods were used to study near-equatorial sea level\nevents. Many events appear to be Kelvin wave pulses generated by westerly\nwind bursts, best described statistically by a Poisson process model. A\nseasonal cycle of event frequency, and interannual variability of both event\nfrequency and event sign were observed in the data.\nTheoretical studies continued, and development began on a model of the\ninfluence of Indian Ocean coastal geometry on equatorial wave generation.\nThis model will be used extensively to look at 40-50 day oscillations in the\nIndian Ocean as part of an India/U.S. bilateral effort on monsoon variability.\nWork on a second model began cooperatively with investigators from JISAO on a\nmodel to study interaction of equatorial waves and mean flows. Studies on\nvertically propagating Kelvin waves have led to a more general study of\nequatorial waves.\nResearch on sea level studies continued in several areas. Operation of\nthe Pacific Sea Level Network continued through 1985, and data were routinely\nprocessed and evaluated. Four additional stations were converted to satellite\ndata transmission, bringing the total to ten. Sea level observations were\nused to estimate the amounts of warm water exchanged during the 1982-83 El\nNiño event; an eastward flux of about 40 X 106 m³ s-1 is indicated.\n258","The TOGA Sea Level Data Center, established in 1984, acquired necessary\nequipment and moved into new accommodations. A data-handling system was\ndeveloped, and the bulk of past monthly mean sea level data for the tropical\noceans was acquired. Acquisition of past daily sea level data from a variety\nof sources started.\nThe Integrated Global Ocean Station System (IGOSS) Sea Level Pilot Pro-\nject, established in early 1984, continued to issue monthly maps of sea level\nfor the Pacific Ocean. Data from 67 stations located in 25 IGOSS member\nstates are included in the analysis for each Pacific map.\nTSUNAMI RESEARCH\nThe construction of five solid-state tsunami gauges was funded by the\nUniversity of Hawaii. The electronic and package work was completed as well\nas design and fabrication of a prototype model. The tsunami observer list was\nupdated with the addition of five new observers.\nPlans FY 1986\nCLIMATE RESEARCH\nExamine the role of tropical storms in ENSO and delineate large-scale\nclimate system fluctuations necessary for their occurrence.\nParticipate in the United States/Peoples Republic of China western\nPacific research project cruises starting in December 1985.\nContinue production of the Pacific Ocean surface wind data set and\nevaluate non-U.S. satellite products and meteorological reports from\nfishing fleets.\nEQUATORIAL OCEANOGRAPHY\nContinue PEQUOD analysis and comparison with NORPAX shuttle observations.\nContinue to operate the Pacific Sea Level Network and convert three more\nstations to satellite data transmission.\nEstablish a data base of the Indian Ocean at the TOGA Sea Level Data\nCenter.\nTSUNAMI RESEARCH\nJIMAR\nDeploy five gauges to test calibration and gain field experience.\n259","JISAO\nThe Joint Institute for Study of the Atmosphere and the Ocean (JISAO) was\nformed in FY 1977 with the University of Washington. The main areas of empha-\nsis within JISAO continue to be climate dynamics, estuarine processes, and\nenvironmental chemistry.\nAccomplishments FY 1985\nCLIMATE\nJISAO contributed to the EPOCS and TOGA programs through the support of\nfour postdoctoral appointees and one visiting scientist whose research in-\nvolved both observational and theoretical studies, and through active partici-\npation in planning for TOGA at the national and international levels.\nA continuing study of nonlinear Rossby waves showed that critical layers\nprovide a theoretical framework on which to base many ideas concerning the\nbreaking of Rossby waves. More and more evidence is becoming available that\nin the atmosphere this process is extremely important in the transport of\npotential vorticity and chemical tracers.\nThis study of nonlinear Rossby waves concentrated on four topics:\n(1) Evolution of a nonlinear critical layer. Novel physical effects in-\nclude the possibility of long+term absorption, the formation of a wake in\nwhich material contours are highly contorted, and the tendency for closed~\nstreamline regions to be inhibited as the enduring vorticity field in turn\nalters the streamfunction.\n(2) Barotropic instability of a nonlinear critical layer. A great deal\nof time was spent on simulating the evolution of the entire nonlinear critical\nlayer including the instability in a numerical model. This effort provided\nvery strong evidence that the instability is highly effective in changing the\nevolution of the nonlinear critical layer. A number of problems remain to be\nsolved before this study is complete.\n(3) Simple analytical and numerical solutions of critical layer behavior.\nA precise picture was revealed of the way in which reflecting/absorbing proper-\nties of critical layers are affected by numerical resolution and flow\ncurvature.\n(4) Research related to the effect of potential vorticity mixing in the\nstratosphere on atmospheric free modes.\nAnother climate study area focused on low#frequency variability of the\nsea level and near surface temperature at the Galapagos Islands during 1979-84.\nThe analysis concentrates on the 2-30 day frequency band where peaks are ob-\nserved at 5 and 12 days.\n260","Previous theoretical work was extended on the ocean response to spectral\nwind forcing on a continental margin, removal of the long-wave approximation,\nhandling the \"corner\" region and merged Ekman layers, and cross shelf varia-\ntion in bottom friction.\nScientific activity at the Experimental Climate Forecast Center focused\non the preparation of a reformatted version of the National Meteorological\nCenter (NMC) data. The new form is intended to be one that can be updated\nwith NMC grids in real time. Real-time diagnostics in the context of the long-\nterm climatic record will then be done.\nENVIRONMENTAL CHEMISTRY\nResearch continued on the absorption and removal of dissolved constit-\nuents in sea water by settling particles, which is termed scavenging. Scaveng-\ning is considered to be one of the main removal mechanisms of trace elements\nfrom seawater and a sink for pollutants in the coastal zone. The rates of\nscavenging under natural conditions were estimated by measurements of the\ndistribution of dissolved and particulate Th-234. Laboratory experiments were\nused to extend the field measurements on Th-234 to a wide range of other\nelements. Experiments on the kinetics and equilibrium uptake of Th-234 and\nother elements by natural marine particulate matter were designed and con-\nducted. Field and laboratory measurements were brought together to develop a\nmodel for scavenging in the open ocean and in Puget Sound. A box model to\npredict the rate of uptake of reactive elements in Puget Sound was\nconstructed.\nJISAO continued its role of facilitating collaboration and interaction\namong environmental chemists working in several departments on the University\ncampus. The annual Environmental Chemistry Day was held on 24 January.\nPlans FY 1986\nContinue an active program in climate with four postdoctoral appointees,\nsenior visiting scientist in residence, and a large number of\na\nshort-term visitors who will be giving seminars.\nSecure funding for continuation of the core program in Environmental\nChemistry.\nSponsor a 3-day workshop on oceanic general circulation in January 1986;\n25 from outside the Laboratory are expected to attend.\nBegin a Distinguished Scientist Program.\nJISAO\n261","","Rex J. Fleming\nSTORM PROGRAM OFFICE\nDirector\nBoulder, Colorado\nDirector\nCooperative\nP/O\nInstitutes\nDep. Director\nSTORM\nESG\nTOGA\nCRP WRP PROFS WMP\nWPL\nARL\nAL\nSEL\nAOML\nPMEL\nGLERL\nGFDL\nNSSL\nThe National Stormscale Operational and Research Meteorology (STORM) Pro-\ngram Office was established in NOAA in November 1984. The office is funded by\nand serves the Federal agencies expected to participate in the National STORM\nProgram, receives its general guidance from the Federal Coordinating Committee\nfor Science, Engineering, and Technology Subcommittee on Atmospheric Research\n(SAR), and obtains its administrative support from the Environmental Research\nLaboratories of NOAA. The main function of the office is to prepare the docu-\nmentation needed to obtain fiscal support for the program, and ultimately, to\nprepare the detailed implementation plans for each of the field phase efforts\nthroughout the 14-year life of the program.\nWEATHER OBSERVATIONS AND PREDICTION\nSTORM is a major interagency operational and research program that will\nenable the United States to deal with the mesoscale weather elements that\nactually affect day-to-day activities. The purpose of the program is to make\ndramatic improvements in observation, prediction, and warning systems for\nthose weather phenomena that take tolls in life and property.\nProgress in meteorology has been significant on the synoptic scale and on\nthe microscale. The mesoscale has eluded us, in a relative sense, for tech-\nnological reasons; the barely perceptible progress over the last 25 years in\nnumerical prediction of precipitation is but one example of this. However,\nwe\nnow have the technology to advance. Soundings from geostationary satellites,\nSTORM\natmospheric wind profiling systems, NEXRAD and other new research radars on\nthe ground and in the air, automated surface stations, rapid communications,\nand new software for display, analysis, and prediction are now here or on the\nimmediate horizon.\n263","The Program Design for STORM-Central had been written in 1984 and en-\ndorsed by the National Academy of Sciences. The plan contains a novel use of\ntechnology and highly skilled people to accelerate technology transfer,\nthrough the use of Experimental Forecast Centers. The plan calls for new\nbasic and applied research, and offers a framework for significant contribu-\ntions to other disciplines such as hydrology and atmospheric chemistry.\nStating that a National STORM Program is long overdue, the National\nAcademy of Sciences recommended that the government take action. In the 98th\nCongress, the Senate passed Senate Concurrent Resolution 109, calling for a\nNational STORM Program with NOAA as the lead agency. The same Congress appro-\npriated FY 1985 funds for NOAA to initiate PRE-STORM activities. A successful\nOklahoma-Kansas PRE-STORM field phase was conducted in the summer of 1985.\nResults will be incorporated into the detailed design of STORM.\nSTORM-Central should begin in the spring of 1990 and will cover the\ncenter third of the country. It will focus on severe weather, flash floods,\nand severe winter storms. It will also concentrate on improving the predic-\ntions of those mesoscale convective systems that bring beneficial rain to the\ncorn and wheat belts. STORM-East is scheduled for the early 1990s, and STORM-\nWest is scheduled for the mid-1990s. Both will have a notable oceanographic\ncomponent.\nThe Federal agencies will work together to implement this program and\nsupply the budgetary and personnel resources required. The budget is large\nrelative to conventional meteorological funding but not large relative to the\nbudgets of other national activities of comparable importance to society.\nAccomplishments FY 1985\nThe STORM Program Office initiated studies and discussions with scien-\ntists, engineers, and potential contractors to define a workable and afford-\nable communications system for the real-time requirements of STORM-Central.\nIt is expected that the Geostationary Operational Environmental Satellite\n(GOES) data collection system of NOAA will be used to deliver data from\nseveral of the automated data systems to be used in STORM-Central. A separate\nreal-time communications network, linking the data sources with the Experi-\nmental Forecast Centers and the Operational Control Center, will be estab-\nlished; its hub will be colocated with the ERL/PROFS facility.\nThe STORM Office established academic working groups to revise the STORM-\nCentral Implementation Plan. More than 80 of the best mesoscale scientists in\ngovernment laboratories and universities have agreed to serve and work toward\ncreating a revised STORM=Central Program Design that will provide a consistent\nscientific direction to mesoscale research.\n264","Plans FY 1986\nFurther studies and discussions will be conducted to define staffing and\nlogistical requirements for each of the major STORM-Central observing\nsystems, and for the forecasting facilities.\nA new budget will be prepared, consistent with the revised timing of\nSTORM:\n- Eliminating or reducing the budget for those elements required in\nSTORM-Central, but now wholly or partially planned for\nimplementation elsewhere.\n- Tightening the budget in specific areas by further use of base\nfunds or other actions.\nSoliciting further support from other agencies whose planned role\n-\nin STORM was slight or nonexistent.\nThe research radar network strategy will be revised on the basis of the\nnew implementation schedule of the Next-generation Radar (NEXRAD)\nsystems in the STORM-Central region.\nThe STORM-Central Program Design document will be revised to be more spe-\ncific about the role of the program in winter storm forecast\nimprovement, STORM-related hydrology, and STORM-related chemistry.\nINTERNATIONAL TOGA PROJECT OFFICE\nThe Director of the National STORM Program Office is also responsible for\nimplementation of the International Tropical Ocean and Global Atmosphere\n(TOGA) Project Office. This office, with its own staff, serves those inter-\nnational organizations supporting the 10-year TOGA program, receives its\ngeneral guidance from the Director of the World Climate Research Programme\n(located in Geneva, Switzerland, within the World Meteorological Organiza-\ntion), and obtains its administrative support from the Environmental Research\nLaboratories of NOAA. Its main function is to prepare Implementation Plans\nfor the TOGA program.\nThe scientific aspects of TOGA have been defined and planned by the TOGA\nScientific Steering Group (SSG) The SSG was established by the Joint Scien-\ntific Committee of WMO and ICSU and by the Committee on Climate Change and the\nOcean (CCCO) formed by the IOC and SCOR. The SSG also formulates scientific\npriorities for the implementation of TOGA.\nResearch on large-scale oscillations of the tropical atmosphere has been\nconducted for more than 80 years. Through the years, scientists correlated\nthese low-frequency atmospheric oscillations with changes occurring in the\nTOGA\ntropical oceans. Later, it was realized that these interactions between the\ntropical oceans and atmosphere were linked to changes of weather and climate\nin the higher latitudes of both hemispheres. However, it is only recently\nthat the latest analyses of data and results from field experiments and theo-\n265","retical work have come together to create a sense of priority in the scien-\ntific community concerning this subject.\nIn the last few years, recognition of the importance of predicting varia-\ntions in the Earth's climate has led to a large increase in individual re-\nsearch investigations. However, it is clear that progress in understanding\nand predicting these climate events will require information about the rele-\nvant atmospheric and oceanic variables. An international activity that will\nprovide this information has been organized and is called the TOGA program.\nTOGA is part of the World Climate Resarch Programme (WCRP) established by the\nWorld Meteorological Organization (WMO) and the International Council of\nScientific Unions (ICSU) to determine to what extent climate can be predicted\nand the extent of human influence on climate. The TOGA program was organized\nwith the joint support of SCOR (ICSU's Scientific Committee for Oceanic Re-\nsearch), WMO, and the UNESCO Intergovernmental Oceanographic Commission (IOC).\nThe scientific community has been aware of the existence of anomalous\noceanic and atmospheric circulation patterns that develop on time scales of\nseveral months to several years, and has recognized that a significant part of\nthese variations can be explained by the dynamics of the coupled system consis-\nting of the tropical oceans and the global atmosphere. The study of this\nsystem is the objective of the TOGA program.\nNew insights have been gained on the planetary-scale monsoon system under\nthe Monsoon Experiment (MONEX) Sub-programme of the First GARP Global Experi-\nment (FGGE), as well as under national, bilateral, and international monsoon\nresearch programs prior to MONEX. The sub-seasonal and interannual variabil-\nity of monsoons is now regarded as having close links with ocean surface con-\nditions on regional and planetary scales. Monsoon variability is also a func-\ntion of interactions with other major atmospheric systems. Recognizing the\nimportant role of the planetary-scale monsoons, as an energy source for the\nglobal atmosphere and as a potential link to Southern Oscillation and El Niño\nevents, the TOGA program has included the study of monsoon variability as an\nimportant element in achieving its overall objectives.\nAccomplishments FY 1985\nA conference on the TOGA Scientific Programme was convened in Paris 17-21\nSeptember 1984. Representatives from 38 countries attended. It was a success-\nful conference and there was considerable enthusiasm for participating in the\nTOGA program. Several representatives from various countries expressed con-\ncern that there needed to be accessible information about TOGA. That informa-\ntion is now being made available.\nThe International TOGA Project Office (ITPO) contributed to two chapters\nof the TOGA Scientific Plan. The plan has been completed and will be distri-\nbuted in October 1985 by the World Meteorological Organization. The ITPO pre-\npared several drafts of the International TOGA Implementation Plan for appro-\npriate review, and the final version was completed in October 1985.\nThe ITPO began publishing a quarterly newsletter, \"TOGA Topics.\" The pur-\npose of the newsletter is to keep the international community informed of\nactivities at the Project Office, to pass along news of interest and, most\n266","important, to provide the meteorological and oceanographic communities with\nrecent information on the status and operation of TOGA.\nThe ITPO also prepared a high quality brochure that describes the TOGA\nprogram in laymen's terms, indicates what contributions are needed, and offers\nsuggestions to countries on how to make such contributions. The brochure is\nto be available in English, French, Spanish, Russian, Japanese, and Chinese.\nThe ITPO produced two satellite films documenting cloudiness and precipi-\ntation during the record 1982-83 El Niño event. One film was composed of a\nsequence of 1-h ull-disk images of GOES-West (135°W) infrared radiances, for\nthe period 1 May 1982 through 20 November 1982. The second film was composed\nof a similar sequence of infrared images from GOES-East (75°W) for the period\n1 November 1982 through 15 June 1983. Copies of these films were distributed\nto countries expressing an interest in TOGA, and a library system of loan\ncopies of these films has been established. The films offer an additional\nscientific tool for assessing the Southern Oscillation phenomena; the second\nfilm is especially interesting because it depicts intense mesoscale convective\nsystems in the eastern Pacific and along the coast of South America--regions\nwhere they rarely occur.\nThe TOGA program had already begun by January 1985. Considerable re-\nsources are already in place (XBT lines, tide gauge stations, and enhanced\nmeteorological observations). The program will continue to evolve as new tech-\nnology becomes available.\nPlans FY 1986\nDistribute 1000 copies of the International TOGA Implementation Plan to\nthe international community.\nPrepare material and make necessary \"marketing\" trips to help the\ninternational organizations supporting the TOGA program achieve the\nremaining data management center commitments.\nPrepare material and letters to various countries and organizations to\nencourage further contributions of observing systems.\nDistribute the TOGA brochure to every country in the world, in English,\nFrench, Spanish, Russian, Japanese, or Chinese. Countries will be\nencouraged to contribute to the TOGA program on a continuous basis--no\ncontribution is too small or too late.\nDistribute \"TOGA Topics\" and Implementation Plan changes to the\ninternational community.\nTOGA\n267","","APPENDIX: Acronyms and Initialisms\nArctic Cyclone Experiment\nACE\nacoustic current meter\nACM\nAutomation of Field Operations and Services (NWS)\nAFOS\nArctic Gas and Aerosol Sampling Program\nAGASP\nAgency for International Development\nAID\nAirborne Investigations of Mesoscale Convective Systems\nAIMCS\nAeronomy Laboratory (ERL)\nAL\nAlpine Experiment\nALPEX\nArgonne National Laboratory\nANL\nAustralian National University\nANU\nAtlantic Oceanographic and Meteorological Laboratory (ERL)\nAOML\nArctic Polynya Experiment\nAPEX\nAirshed Photochemical Model\nAPM\nAir Resources Laboratory (ERL)\nARL\nAir Route Traffic Control Center\nARTCC\nAtmospheric Studies in Complex Terrain (DOE)\nASCOT\nAtmospheric Transport and Diffusion [model]\nATD\nAtmospheric Turbulence and Diffusion Division (ARL)\nATDD\nAutomated Temperature Line Acquisition System\nATLAS\nAnalysis of the Tropical Ocean Lower Layer\nATOLL\nAdvanced Weather Interactive Processing System for the 1990's\nAWIPS-90\nAir Weather Service (USAF)\nAWS\nairborne expendable current probe\nAXCP\nBoulder Atmospheric Observatory (ERL)\nBAO\nClimate Analysis Center (NWS/NMC)\nCAC\ncontrol and monitoring system\nCAMS\nCross-Appalachian Tracer Experiment\nCAPTEX\nCommittee on Climate Change and the Ocean IOC-SCOR)\nCCCO\nClimatological Dispersion Model\nCDM\nCryospheric Data Management System\nCDMS\nComputer and Engineering Support and Development (NSSL)\nCESD\ncloud to ground\nCG\nChicago - University of Illinois [radar system]\nCHILL\nCooperative Institute for Marine and Atmospheric Studies\nCIMAS\nCooperative Institute for Mesoscale Meteorological Studies\nCIMMS\nCooperative Institute for Research in the Atmosphere\nCIRA\nCooperative Institute for Research in Environmental Sciences\nCIRES\nComprehensive Ocean-Atmosphere Data Set\nCOADS\nCoastal Ocean Dynamics Applications Radar\nCODAR\nCorps of Engineers (U.S. Army)\nCOE\nContinental U.S. Meteorological Data System\nCOMEDS\nConvective Dispersion Observed by Remote Sensors\nCONDORS\ncarbon, oxygen, phosphate\nCOP\nClimate Research Project (ERL/ESG)\nCRP\nCommonwealth Scientific and Industrial Research Organization\nCSIRO\n(Australia)\nColorado State University\nCSU\nconductivity, temperature, depth\nCTD\nComplex Terrain Diffusion Model\nCTDM\nCentral Weather Processor (FAA)\nCWP\n269","DAR3E\nDenver AWIPS-90 Risk Reduction and Requirements Evaluation\n(FAA)\nDMS\ndimethyl sulfide\nDMSP\nDefense Meteorological Satellite Program\nDOD\nDepartment of Defense\nDOE\nDepartment of Energy\nDOM\ndissolved organic material\nDOPLIGHT\nDoppler-Lightning\nDOPLOON\nDoppler-balloon\nDRASER\nDoppler Radar And Storm Electricity Research (NSSL)\nDWBC\ndeep western boundary current\nECC\nelectrochemical concentration cell\nEDA\nenergy dispersive analysis\nENAMAP\nEastern North American Model of Air Pollution [superseded; see\nRELMAP]\nENSO\nEl Niño/Southern Oscillation\nEOF\nempirical orthogonal function\nEPA\nEnvironmental Protection Agency\nEPOCS\nEquatorial Pacific Ocean Climate Studies\nERL\nEnvironmental Research Laboratories (NOAA)\nESG\nEnvironmental Sciences Group (ERL)\nEUC\nEquatorial Undercurrent\nEUV\nextreme ultraviolet\nEWH\necho weak hole\nFAA\nFederal Aviation Administration\nFACE\nFlorida Area Cumulus Experiment\nFACTS\nFlorida Atlantic Coast Transport Study\nFASINEX\nFrontal Air-Sea Interaction Experiment\nFGGE\nFirst GARP Global Experiment\nFM-CW\nfrequency modulation-continuous wave\nFOCI\nFisheries Oceanography Cooperative Investigations (NOAA)\nFOX\nFishery Oceanography Experiment\nGAGE\nGlobal Atmospheric Gas Experiment\nGALE\nGenesis of Atlantic Lows Experiment\nGARP\nGlobal Atmospheric Research Program\nGC\ngas chromatography\nGCM\ngeneral circulation model\nGCM\nGlobal Climate Monitoring\nGFDL\nGeophysical Fluid Dynamics Laboratory (ERL)\nGLERL\nGreat Lakes Environmental Research Laboratory (ERL)\nGMCC\nGeophysical Monitoring for Climatic Change (ARL)\nGOES\nGeostationary Operational Environmental Satellite\nGPS\nGlobal Positioning System\nGTN\nGlobal Trends Network\nGTS\nGlobal Telecommunication System\nGWMF\ngravity wave momentum flux\nHEPAD\nHigh Energy Proton and Alpha Detector\nHF\nhigh frequency\nHPBL\nhurricane planetary boundary layer\nHPLC\nhigh performance liquid chromatography\n270","highly reflective clouds\nHRC\nInternational Association for Great Lakes Research\nIAGLR\nInterplanetary Cometary Explorer\nICE\nInternational Council of Scientific Unions\nICSU\ninverted echo sounder/pressure gauge\nIES/PG\nIntegrated Global Ocean Station System\nIGOSS\ninterplanetary magnetic field\nIMF\nInertial Navigation System\nINS\nIntergovernmental Oceanographic Commission (UNESCO)\nIOC\nIntergovernmental Personnel Act\nIPA\nInternational TOGA Project Office\nITPO\nInternational Ursigram and World Days Service\nIUWDS\nJoint Airport Weather Studies\nJAWS\nJoint Ice Center\nJIC\nJoint Institute for Marine and Atmospheric Research\nJIMAR\nJoint Institute for Study of the Atmosphere and Ocean\nJISAO\nJoint System Program Office (NEXRAD)\nJSPO\nKennedy Space Center\nKSC\nLos Alamos National Laboratory\nLANL\nliquid chromatography\nLC\nlimited-area fine mesh\nLFM\nLawrence Livermore National Laboratory\nLLNL\nlaser magnetic resonance\nLMR\nLong-Range Effects Research Program\nL-RERP\nMesoscale Applications Group (ESG/WRP)\nMAG\nMiddle Atmosphere Program (SEL)\nMAP\nMesoscale Analysis and Prediction System (PROFS)\nMAPS\nmesoscale convective complex\nMCC\nmesoscale convective system\nMCS\nMedium Energy Proton and Electron Detector\nMEPED\nMetropolitan Tracer Experiment\nMETREX\nmovable fine-mesh [hurricane model]\nMFM\nmulti-frequency acoustic plankton survey\nMFPS\nmagnetohydrodynamic\nMHD\nMarginal Ice Zone Experiment\nMIZEX\nmultiple opening/closing net environmental sensing system\nMOCNESS\nMonsoon Experiment (FGGE)\nMONEX\nMesoscale Research Group (ESG/WRP)\nMRG\nmass spectrometry\nMS\nMesoscale Studies Group (ERL/ESG)\nMSG\nmesosphere-stratosphere-troposphere\nMST\nNational Acid Precipitation Assessment Program\nNAPAP\nNational Aeronautics and Space Administration\nNASA\nNational Bureau of Standards\nNBS\nNational Center for Atmospheric Research\nNCAR\nNational Climatic Data Center (NESDIS)\nNCDC\nNational Data Buoy Center\nNDBC\nNorth Equatorial Countercurrent\nNECC\n271","NESDIS\nNational Environmental Satellite, Data, and Information Service\n(NOAA)\nNEXRAD\nNext-generation weather Radar\nNHC\nNational Hurricane Center (NWS)\nNICG\nNational Interagency Coordinating Group\nNMC\nNational Meteorological Center (NWS)\nNMFS\nNational Marine Fisheries Service (NOAA)\nNOAA\nNational Oceanic and Atmospheric Administration\nNOMAD\nNavy Oceanographic Meteorological Automatic Device\nNORPAX\nNorth Pacific Experiment\nNRC\nNuclear Regulatory Commission\nNSF\nNational Science Foundation\nNSSL\nNational Severe Storms Laboratory (ERL)\nNWAFC\nNorthwest and Alaska Fishery Center\nNWP\nnumerical weather prediction\nNWRI\nNational Water Research Institute (Canada)\nNWS\nNational Weather Service (NOAA)\nOAR\n[Office of] Oceanic and Atmospheric Research (NOAA)\nODW\nOmega dropwindsonde\nO-K PRE-STORM\nOklahoma-Kansas PRE-STORM\nPACE\nPrecipitation Augmentation for Crops Experiment\nPAH\npolycyclic aromatic hydrocarbon\nPAM\nportable automated mesonetwork\nPBL\nplanetary boundary layer\nPEQUOD\nPacific Equatorial Ocean Dynamics\nPMEL\nPacific Marine Environmental Laboratory (ERL)\nPOWER\nPROFS Operational Weather Education and Research\nPOWS\nPROFS Operational Work Station\nPPI\nplan position indicator\nP-PRIME\nPollutant-Particle Relationships In the Marine Environment\nPRECP\nProcessing of Emissions by Clouds and Precipitation\nPRE-STORM\nPreliminary Regional Experiment for STORM-Central\nPROFS\nProgram for Regional Observing and Forecasting Services\n(ERL/ESG)\nPROVAS\nProfiler-VAS\nQSTING\nquasi-spectral time integration on nested grids\nRADAP\nRadar Data Processor\nRADM\nRegional Acid Deposition Model\nRELMAP\nRegional Lagrangian Model of Air Pollution\nRFC\nRiver Forecast Center (NWS)\nRITS\nRadiatively Important Trace Species\nROM\nRegional Oxidant Model\nRSMAS\nRosenstiel School of Marine and Atmospheric Science\n(U. of Miami )\nSAGE\nStratospheric Aerosol and Gas Experiment\nSANBAR\nSander's Barotropic [model]\nSAR\nSubcommittee of Atmospheric Research (STORM)\nSBUV\nsolar backscatter ultraviolet\nSCCCMP\nSouth Central Coast Cooperative aerometric Monitoring Program\n272","Scientific Committee for Oceanic Research (ICSU)\nSCOR\nSatellite Data Handling System\nSDHS\nSoutheast Area Monitoring and Assessment Program\nSEAMAP\nSouth Equatorial Current\nSEC\nSouth Equatorial Countercurrent\nSECC\nSouthEast Fisheries Center (NMFS)\nSEFC\nSpace Environment Laboratory (ERL)\nSEL\nSEL Data Acquisition and Display System\nSELDADS\nSEL Solar Imaging System\nSELSIS\nSpace Environment Monitor\nSEM\nSpace Environment Services Center (SEL)\nSESC\nstepped-frequency microwave radiometer\nSFMR\nScripps Institution of Oceanography\nSIO\nshuttle imaging radar\nSIR\nSystem for Locating Eruptive Underwater Turbidity and\nSLEUTH\nHydrography\nSolar Mesosphere Explorer\nSME\nSolar Observing Optical Network\nSOON\nsuspended particulate matter\nSPM\nScientific Steering Group (TOGA)\nSSG\nsea surface temperature\nSST\nstratosphere-troposphere\nST\nSubtropical Atlantic Climate Studies\nSTACS\nStormscale Operational and Research Meteorology\nSTORM\nsolar x-ray imager\nSXI\nTrans-Atlantic Geotraverse\nTAG\nTsunami Hazard Reduction Using System Technology\nTHRUST\nTelevision and Infrared Observation Satellite\nTIROS\nTropical Modeling and Analysis Program (PMEL)\nTMAP\nTropical Oceans and Global Atmosphere\nTOGA\nTotable Tornado Observatory\nTOTO\nThunderstorm Research International Program\nTRIP\ntornado vortex signature\nTVS\nUpper Great Lakes Connecting Channels Study\nUGLCCS\nU.S. Air Force\nUSAF\nU.S. Geological Survey\nUSGS\nultraviolet\nUV\nvector-averaged current meter\nVACM\nvelocity-azimuth display\nVAD\nVISSR Atmospheric Sounder\nVAS\nVenting Experiment\nVENTEX\nvery high frequency\nVHF\nVisible Infrared Spin-Scan Radiometer\nVISSR\nvery low frequency\nVLF\nvolume velocity processing\nVVP\nWestern Atlantic Ocean Experiment\nWATOX\nWorld Climate Research Programme (WMO-ICSU)\nWCRP\nWestern Equatorial Pacific Ocean Circulation Study\nWEPOCS\nWorld Meteorological Organization\nWMO\nWeather Modification Program (ERL/ESG)\nWMP\n273","WOCE\nWorld Ocean Circulation Experiment\nWPL\nWave Propagation Laboratory (ERL)\nWRIPS\nWave Rider Information Processing System\nWRP\nWeather Research Program (ERL/ESG)\nWRR\nWorld Radiometer Reference\nWSFO\nWeather Service Forecast Office\nWVR\nwater vapor radiometer\nWWA\nWorld Warning Agency\nWWCE\nwesterly wind/convection episode\nXBT\nexpendable bathythermograph\n274\n* U.S. GOVERNMENT PRINTING OFFICE:1986-676-002/40010"]}