{"Bibliographic":{"Title":"Climate Analysis Center FY 1991 Annual Report","Authors":"","Publication date":"1990","Publisher":""},"Administrative":{"Date created":"08-16-2023","Language":"English","Rights":"CC 0","Size":"0000218170"},"Pages":["NHC\n3\nCLIMATE ANALYSIS CENTER\nFY 1991\nANNUAL REPORT\nNational Hurricane Library\n1320 S. Dixie Hwy.\n6th Floor, Room 631\npies Florida 33146\nU.S. DEPARTMENT OF COMMERCE\nNational Oceanic and Atmospheric Administration\nNational Weather Service\nNational Meteorological Center\nQC\n851\n.C5\nC55","QC\n851\nC5\nOF\nC55\n*\n*\nAvenue\nSTATES\nOF\nNational Hurricane Library\n1320 S. Dixie Hwy.\n6th Floor, Room 631\nCoral Gables, Florida 33146\nCLIMATE ANALYSIS CENTER\nFY 1991\nANNUAL REPORT\nTECHNICAL EDITOR: LUKE MANNELLO\nJanuary 1992\nU.S. DEPARTMENT OF COMMERCE\nNATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION\nNATIONAL WEATHER SERVICE\nNATIONAL METEOROLOGICAL CENTER\nNOAA Coral Gables Library Center\n1320 South Dixie Highway, Room 520\nCoral Gables, Florida 33146\n1712","","FY 1991 ANNUAL REPORT\nTABLE OF CONTENTS\nPage\nSTAFF OF THE CLIMATE ANALYSIS CENTER.\niv\nEXECUTIVE SUMMARY\nV\n1.\nCLIMATE DIAGNOSTICS\n1\nTropical Ocean/Atmosphere Interaction\n1.1\n1\nCirculation Diagnostics\n1.2\n5\n2.\nCLIMATE MONITORING\n21\n2.1\nSurface Climate\n21\nClouds and Precipitation\n2.2\n29\n2.3\nAtmospheric Circulation\n31\nOperational Products\n2.4\n41\n3.\nSTRATOSPHERE AND TRACE GASES\n47\n3.1\nField Analysis\n47\n3.2 Ozone/Temperature Trends\n48\n3.3\nOperational Products\n52\n4.\nAPPLIED CLIMATOLOGY\n55\n4.1\nSurface Data\n55\nAgricultural Applications\n4.2\n58\n4.3\nClimate Impacts: Monitoring\n58\nOperational Products\n4.4\n64\n4.5\nSupporting Projects\n68\n5.\nCLIMATE PREDICTION\n75\n5.1\nEmpirical Studies\n75\n5.2\nDynamical Methods\n80\n5.3 Evaluation\n96\n5.4\nOperational Products\n98\n5.5\nSupporting Projects\n105\n6.\nSUMMARIES\n107\n6.1\nClimate and Global Change Program\n107\nTOGA Activities\n6.2\n107\n6.3\nEPOCS Activities\n107\nBilateral Activities\n6.4\n108\nWorld Climate Program Activities\n6.5\n109\nNational Weather Service Programs\n6.6\n110\nAnnual Climate Diagnostics Workshops\n6.7\n111\n7.\nBIBLIOGRAPHY\n113\nJournal Articles\n7.1\n113\n7.2\nArticles in Non-Refereed Literature\n115\nPresentations at Formal Scientific Meetings\n7.3\n120\nSeminars and Briefings\n7.4\n125\n7.5\nGrant/Contract Program\n129\nCAC-Sponsored Seminar Series\n7.6\n130\n7.7\nVisitors\n136\niii","STAFF OF THE CLIMATE ANALYSIS CENTER\nOFFICE OF THE DIRECTOR\nDirector, D. R. Rodenhuis\nSecretary, G. S. Lucas\nE. S. Epstein\nL. P. Mannello\nA. M. Wieser\nPREDICTION BRANCH\nANALYSIS & INFORMATION BRANCH\nChief H. M. van den Dool 1\nChief, J. D. Laver\nSecretary, K. Donaldson\nSecretary, E. Michaelides\nJ. Anderson 2\nR. J. Bermowitz\n4\nA. M. Artusa\nN. L. Canfield\nA. G. Barnston\nR. H. Churchill\nW- Y. Chen\nJ. M. Dionne\nW. N. Ebisuzaki 3\nG. G. Fulwood\nJ. D. Hoopingarner\nM. E. Gelman\n3\nHuang\nJ.\nJ. A. Harrison\nF. D. Hughes\nT. R. Heddinghaus\n3\nR. E. Livezey\nA.\nHerman\nR.\nMartin\nB.\nHurley\nA. H. Murphy 2\n3\nS.\nKatz\nE. A. O'Lenic\nM.\nKnezevic\nR.\nSchechter\nR. L. Lehman\nTian 3\nP.\nC. S. Long\nM. S. Tracton\nA. J. Miller\nA. J. Wagner\nD.\nMiskus\nR. M. Nagatani\n3\nDIAGNOSTICS BRANCH\nA.\nOngurer\nP.\nSabol\nChief, C. F. Ropelewski\nD.\nStutzer\nSecretary, P. Davis\nL. K. Thomas\nR.\nJ.\nTinker\nWild 3\nBassist\nA.\nJ.\n3\nJ. D. Bell\nYang3\nS-K.\nChelliah 3\nM.\nD. R. Garrett\nAGRICULTURAL WEATHER SECTION\nM. S. Halpert\nJ. E. Janowiak\nChief, D. M. LeComte\nJ. D. Kopman\nSecretary, J. Houston\nV. E. Kousky\nK. C. Mo\nV.\nBjerknes\nPan 3\nJ.\nO. W. Byrd\n4\nE. M. Rasmusson\nB.\nRippey\n3\nSchultz\nP.\nD.\nSecora\n2\nSmith\nT.\nR. J. Stefanski\nJ.\nWang\n2. Visiting Scientist\n1. IPA\n3. Contractor\n4. Research Associate, CICS\niv","EXECUTIVE SUMMARY\nINTRODUCTION\nAfter another year in a \"growth industry\" of climate-related\nissues, the variety of projects and interests at the Climate\nAnalysis Center (CAC) defies a concise summary. Within a\ngrowing and changing environment, the mission of the CAC should\nbe emphasized, that is, \"to maintain a continuous watch on\ncurrent climate fluctuations and diagnose and predict them. \"\nThese efforts are designed to assist in coping with climate-\nrelated applications to food supply, water resources, and energy\nallocation.\nThis year we can present a record of progress in the monitoring\nof climate anomalies, in the development of diagnostic tools,\nand in the improvement of forecasting methods for a unified\nsuite of four climate outlook products: 6-10 days, monthly,\nseasonal, and ENSO. In addition, we have taken on a new program\n(Regional Climate Centers) which is focused on regional climate\nservices and applications. Through this program, we hope to\ncontinue to improve our ability to apply research results to\npractical problems which will benefit the national economy.\nI.\nNEAR REAL-TIME CLIMATE PRODUCTS\nMonthly Climate Diagnostics Bulletin - Improvements include the\nexpansion of the Bulletin to include \"Discussion and Outlook\"\nof global ENSO-related climate anomalies in the Forecast Forum,\na significant expansion of the discussions of extra-tropical\nclimate, and augmentation of figures used in ocean diagnostics.\nData sets from the Climate Diagnostics Bulletin were, for the\nfirst time, made available on the CAC Climate Dial-Up Service;\nthus, allowing other NOAA Offices, Government Agencies and\nUniversity scientists easy access to these data.\nENSO Advisories - The current ENSO event stimulated a new set of\nAdvisories to provide real-time assessments of the evolving warm\nepisode. These advisories served as the scientific basis of\nENSO monitoring for the governments of several South American\ncountries as well as the domestic and foreign media.\nClimate Diagnostics Data Base (CDDB) - A comprehensive plan was\nformulated to improve and enhance the CDDB. Elements of this\nplan addressed the relationship of the CDDB to the Climate Data\nAssimilation System (CDAS) and the Reanalysis Project and\nexpanded current data base activities to include satellite data\n(the Satellite Climate Diagnostic Data Base) coupled model\nassimilated data, and input from the ETA model.\nV","Decadal Review - CAC produced, coordinated, and distributed the\npublication: \"Climate Assessment - A Decadal Review 1981-1990\".\nThis review represented a syntheses of NOAA's understanding of\nthe state of the global climate over the past decade. This is\nthe second year of this publication which we plan to establish\nas standard for end-of-the-year climate assessment.\nGraphics - Improvements in the quality of graphical climate\nproducts have been made in a number of steps.\nFor example,\nmachine-independent applications, use of optimum interpolation,\nand incorporating scanning and desk-top-publishing techniques.\nAs a result, quality has improved and automation of products has\npermitted meteorologists more time for their primary tasks.\nCAC Routine Products - A complete list of CAC routine products\nunder climate services, climate diagnostics, and climate\nprediction follows this Summary.\nII. REGIONAL CLIMATE CENTERS PROGRAM\nProject Office - A Project Office was established at the CAC\n(November 1990), for regional climate applications and services.\nThe program of six Regional Climate Centers (RCCs) was organized\nwith a plan which recognizes the importance of consensus\ndecisions, prompt funding of the Centers, development of\nregional services and research programs, peer review at the\nregional and national levels, and the flexible application of\nthese principles to the needs of each center. Also,\na\ncomprehensive RCC Budget Initiative for FY 1993 was written for\nan expanded RCC program to include a solar radiation network,\nclimate impacts research, and applications of research results\nfrom the Global Change Research Program.\nA Climate User Community - A national user community for climate\nproducts and services drawn from private industry, state and\nlocal governments, and academia is being developed. To support\nthis effort, CAC has developed a real-time national data backup\ncapability for the RCCs and is developing an NWS product\ndelivery system for them. Selected RCC products (e.g. impact\nassessments) are being distributed to NWS Regional Offices. The\nRCCs maintain unique data sets which are not available at\nnational centers and can identify and educate potential users on\nthe availability and means to obtain climate data and products.\nvi","III. CLIMATE DIAGNOSTICS RESEARCH\nCDAS and Reanalysis Projects - The CAC has maintained an active\nsupportive role in the development of the Climate Data\nAssimilation System (CDAS) and the planning of the Reanalysis\nProject. In particular, CAC scientists planned and executed an\nextremely difficult and complex series of diagnostics analyses\nof NMC model output for the CDAS project. These analyses\n(comparisons among the T40, T60, and T80 models) served as the\nbasis for further development of both the CDAS and Reanalysis\nProjects.\nDiagnostics of Tropical Precipitation - As part of the\ninternational Global Precipitation Climatology Project, the CAC\nwas designated as an \"Algorithm Intercomparison Center.\" This\nCenter worked effectively with other U. S. Government Agencies,\nas well as with representatives from other nations (Germany,\nJapan, United Kingdom) to conduct a successful cooperative\nprecipitation intercomparison study.\nImproved Empirical ENSO Prediction - The operational statistical\nENSO prediction method based on correlation analysis was\nimproved in content and presentation. These ENSO predictions\nappear regularly in the Monthly Climate Diagnostics Bulletin and\n\"official\" CAC ENSO forecast. These empirical forecasts will be\na standard for judging improvements in model prediction.\nASOS Intercomparison A special session on ASOS-Climate issues\nwas organized and held at the 15th Climate Diagnostics Workshop\nfollowed by a working meeting of the ASOS Climate Working Group\nin October 1990. This meeting provided a basis for the\ndevelopment of a comprehensive ASOS temperature intercomparison\nstudy in cooperation with the NESDIS/ National Climatic Data\nCenter and the University of Colorado. Management of these\nstudies was turned over to the NWS/Office of Meteorology and\nfunded by the new NOAA/ESDIM Activity.\nImproved Ocean Diagnostics- New diagnostics analyses techniques\nwere initiated which utilize assimilated data from oceanic,\natmospheric, and coupled models . These techniques are designed\nto improve the operational monitoring of ENSO variability and\nrelated research. This new activity is being carried out in\ncooperation with NOAA/ERL and the university community under\nEPOCS funding.\nvii","IV. CLIMATE PREDICTION\nClimate Outlooks - Record skill scores for the 6-10 day\nforecasts were achieved on final U. S. surface temperature and\nprecipitation forecasts for several months during FY 1991. This\nwas due to: 1) continuous improvements of raw forecasts\nby\nmodels, 2) the high level of predictability of persistent flow\nobserved during Spring 1991, and 3) increased experience\nwith\nnumerical products. Monthly and seasonal skill scores were\nvariable. Some forecasts were highly successful; but, some\nhad large discrepancies. As usual, CAC forecasters had frequent\ninteractions with the public and the media during the year.\nVerification Summary - Forecast verification summaries that\nhighlight the temporal history of skill for both monthly mean NH\nheights and U.S. surface temperature have been published\nnationally (Proceedings of the 15th Annual Climate Diagnostics\nWorkshop) and internationally (ITCP/WMO Report on the Technical\nConference on Long-Range Weather Forecasting Research). These\nreports highlight positive trends in skill, including the\nachievement of a clear advantage over persistence in the 1980's.\nDERF Program - The operational, bi-weekly lagged forecast\nexperiment was restructured to consist of 9 members at 6 hour\nspacing. Continuous adjustment took place in response to ever-\nchanging computer resources. An improved version of lagged\nforecasting was developed that appears to be successful.\nFollowing the recommendations of a DERF Workshop (Boulder, CO,\nJune 1990) about 20 cases were selected that would provide the\nbest tests for models to investigate Monte Carlo forecasts,\nsensitivity to resolution, and the impact of observed SST.\n10-YEAR RUN - The same model used to generate 128 90-day\nforecasts (DERF90 Experiment) was also used for a successful 10-\nyear run. The amplitude and phase of the annual cycle were\nbetter than expected. One issue, the inclusion of mass sinks and\nsources due to water, was found to be important in the annual\ncycle. As a result, the CAC recommended that a change be made\nin the continuity equation of the MRF. It appears that this\nchange has a positive impact on the 1-10 day forecast as well.\nIn addition to the above activities, CAC scientists participated\nin many National and International Programs (see Section 6)\nScientific articles have been published and a number of formal\npresentations were made (see Section 7). It is appropriate,\ntherefore, to conclude this Summary with an acknowledgment to\nthe entire CAC staff for all of the above accomplishments.\nDavid R Rodenhuis\nDirector, CAC\nviii","NOAA/NATIONAL WEATHER SERVICE\nNATIONAL METEOROLOGICAL CENTER\nCLIMATE ANALYSIS CENTER\nMISSION\nThe mission of the Climate Analysis Center is to maintain\na continuous watch on short-term climate fluctuations and\nto diagnose and predict them. These efforts are designed\nto assist agencies both inside and outside the federal\ngovernment in coping with such climate-related problems\nas food supply, energy allocation, and water resources.\nPRODUCTS\nWeekly Climate Bulletin\nSpecial Climate bulletins\nDrought Advisories\nClimate Dial-Up Service\nDaily Weather Maps\nWeather and Climate Update\nPrecipitation Summary & Temperature Observations (PRESTO)\nWeekly Weather and Crop Bulletin\nSpecial Agricultural Bulletins\nWeekly Agricultural Assessment Briefings\nGlobal Stratospheric Analyses\nGlobal Ozone Analyses and Trends\nMonthly Climate Diagnostics Bulletin [real-time & delayed]\nMonthly Global Atmospheric Analyses\nMonthly Global Oceanic Analyses\nENSO Advisories\nSeasonal Climate Review Article (J. of Climate)\nMedium-Range (6-10 day) Outlook [3 times weekly]\nMonthly Outlook\n(semi-monthly)\nSeasonal Outlook\n[monthly]\nAnnual Climate Diagnostics Workshop\nix","THIS PAGE INTENTIONALLY LEFT BLANK\nX","1. CLIMATE DIAGNOSTICS\n1.1\nTropical Ocean - Atmosphere Interaction\n1.1.1\nOcean-Atmosphere Coupling (Kousky, Ropelewski, Smith,\nChelliah)\nThe goal of this collaborative project (with NMC/Coupled\nModel Group) is to develop an understanding of the evolution of\nthe Southern Oscillation in the ocean-atmosphere coupled system.\nA system is being designed that will enable detailed diagnostics\nto be performed on the coupled ocean-atmosphere model runs.\nThus far, efforts have focused on joint principal component\nanalysis of blended monthly SST anomalies and cross sections of\nocean temperature anomalies. Figure 1 shows the first mode of\nanalysis of north-south cross section temperature anomalies at\n165°E, and 110° W with an east-west section along the equator\n(1985 1991). This mode clearly shows the dominance of the warm\nENSO event in 1986-1987, and the cold event in 1988. Loadings\nalong the equator show the near surface temperature variations\nover the period, extending deepest in the east due to deepening\nor shoaling of the thermocline. The 110°W section's loadings\nsuggest variability in the strength of the North Equatorial\nCurrent, as well as equatorial temperature variation associated\nwith the warm and cold event. At 165°E, most of the\ntemperatures are out of phase with the dominant equatorial\nsurface event.\nIn another joint study (with R. Reynolds, NMC), tests\nfor optimal averaging (OA) of SST were completed for 10°x10°\nareas. The OA is a statistical averaging technique which\nminimizes least-squared error and uses the same statistics as\nthose needed for optimal interpolation (OI) The principle\nadvantage of OA is that it improves the accuracy of area\naverages in regions where data are unevenly distributed. The\nstatistics used in OA and OI have been computed directly from\nSST data, which improves their accuracy over earlier estimates.\nA year of SST increments were assembled from day and nighttime\nsatellite observations as well as ship and buoy data. To date\nstatistics have been computed within non-overlapping 200x206\nocean areas. Table 1 shows globally-averaged statistics for the\nvarious data types, as well as the values currently used by the\nOI. The analysis error standard deviation, in theory, should be\nthe same for each data type, and the relative closeness of the\ndifferent estimates is encouraging. A test of the OI using the\nnew globally constant statistics was computed and compared to\nthe operational version. The results (figure 2) show that the\ncomputed statistics yield a smoother SST field than the\noperational statistics do. The major reason is the increase in\nsize of the correlation scale, which tends to smooth out\nsmaller-scale features. The overall pattern and the magnitude\nof highs and lows is the same in both versions.\n1","PCA OF 3 OCEAN TEMP X-SECTIONS AT EQ. EOF MODE 1\nOM\n100M\n200M\n(a)\n300M\n400M\n500M\n120E\n140E\n160E\n180\n160W\n140W\n120W\n100W\nBOW\nAT 155E\nOM\n100M\n200M\n(b)\n300M\n400M\n500M\n203\n10S\nEQ\n10N\n20N\nAT 110W\nOM\n100M\n(c)\n200M\n300M\n400M\n500M\n20S\n10S\nE2\n10N\n20N\nPCA-MON.ANOM ALL-3 OCEAN-TEMP CROSS SECT-ROT MODE# I /5\n2400\n2000\n1600\n1200\n800\n(d)\n400\n0\n-400\n-800\n-1200\n-1600\n-2000\n-2400\n1985\n1986\n1987\n1988\n1989\n1990\n1991\nYEAR\nFigure 1:\nRotated joint principal component analysis of ocean\ntemperature anomalies on cross-sections: east-west\nalong the equator (a) , north-south at 165E (b)\n,\nnorth-south at 110W (c) . The first mode loadings and\nassociated time series is shown in (d) .\n2","Table 1: Computed global averages of the correlation scale (D),\nstandard deviation of the data error (Sd) , standard deviation of\nthe analysis error (S) and ratio of the standard deviation\nof\nthe data error to analysis error (Sd/Sa). . Data types are day\nsatellite (DSAT) , night satellite (NSAT), ship data (SHIP) , buoy\ndata (BUOY) , and the combined satellite data (DS+NS). . For\ncomparison, the estimates currently used in the operational OI\nfor satellites, ships, and buoys are also given.\nI\nD (Km)\nSd\nS a\nS d / S a\nComputed:\nDSAT\n686\n0.41\n0.48\n0.85\nNSAT\n740\n0.31\n0.36\n0.86\nDS+NS\n705\n0.37\n0.43\n0.86\nSHIP\n947\n1.31\n0.50\n2.94\nBUOY\n901\n0.75\n0.51\n1.34\nOperational:\nDSAT\n222\n0.50\n0.50\n1.00\nNSAT\n222\n0.50\n0.50\n1.00\nSHIP\n222\n0.90\n0.50\n1.80\nBUOY\n222\n0.50\n0.50\n1.00\n3","(CL)\n60W\n40W\n20W\n0\n20E\n140E\n160E\n180\n160W\n140W\n120W\n100W\n80W\n20E\n40E\n60E\n80E\n100E\n120E\n80N\n80N\n38.15\n-10cm\n323\n6\n4 30 0\n60N\n60N\n14\no 2\n1-816\nD\n948\n3\n19\n20\nO\n2\n20\n40N\n24%\n40N\n223,\n2213\n4\n22\n4\n25\n27\n22\n27\n24\n2805\n26\n290\n26.\n29376000\n27\n$\n28\n20N\n28\nUsg\n20N\n26\n24\nLos\n29th\n27m\n29\n29\n2028\n282\n25\n28\n24\n27\ne\n28\n29\n26\n524\n0\n0\nD\n2969\n.8\n23\n2828\n26\n00\n2\n24\n7\n124\n24\n7\n20S\n20\n4\n20S\n16\n23\n4\n16\n6\n2\nNAO\n40S\n40S\n10\n60S\n60S\nWHILE\n80S\n80S\n20W\n0\n20E\n160W\n140W\n120W\n100W\n80W\n60W\n40W\n20E\n40E\n60E\n80E\n100E\n120E\n140E\n160E\n180\n22 SEP 91 TO 28 SEP 91\n(NO BIAS COR: 1-2-1) SST ANALYSIS\nOI\n(b)\n0\n20E\n120E\n140E\n160E\n180\n160W\n140W\n120W\n100W\n80W\n60W\n40W\n20W\n20E\n40E\n60E\n80E\n100E\n80N\n80N\n-10\n00\nRS\n00\n775\n9\n60N\n60N\n2\n4\n4\n19\n7\n18\n9\n40N\n40N\n23\n28\n28\n2\n20N\n2\n20N\n25%\n<04\n2\n2\n2627\n24\n28\n27\n0929\n0\n0\n20\n00\n25\n21\n12\n7\n$25\n7\n2\n2\n20S\n20S\n20\n23\n22\n6\n22\n20\n14\n161616\n13\n2\n40S\n40S\n12\na\n0\n60S\n60S\n80S\n80S\n20E\n40E\n60E\n80E\n100E\n120E\n140E\n160E\n180\n160W\n140W\n120W\n100W\n80W\n60W\n40W\n20W\n0\n20E\nOI (NO BIAS: TEST) SST ANALYSIS, D=700 KM 22 SEP 91 TO 28 SEP 91\nFigure 2 :\nThe OI of SST with no bias correction for the week of\nSeptember 22, 1991 using (a) the operational\nstatistics and (b) the computed statistics.\n4","1.2.\nCirculation Diagnostics\n1.2.1 Large Scale Tropical Circulations (Mo, Rasmusson)\nIn this study, an examination was made of tropical extra-\ntropical linkages during the 1987-1989 ENSO cycle. Figure 3\nshows the 200 mb streamfunction and divergence differences\nbetween the warm and cold seasons during the Northern Hemisphere\nwinter. The linkages between the equatorial Pacific convection\nanomalies and the extratropical circulation are viewed in terms\nof regional Hadley component anomalies and the tropical extra-\ntropical divergence anomaly zones. The primary ingredients of\nthe coupling are: the subsiding branch of the anomalous Hadley\ncell in the North Pacific (figure 3a), enhanced downstream\nsubtropical westerlies across the Gulf of Mexico into the\nAtlantic, and an equatorward enhancement of 200 mb synoptic\nscale variability associated with the enhanced westerlies\n(figure 3b) The northeastward extension of the anomalous\nequatorial convection across Mexico into the Gulf of Mexico and\nAtlantic gives rise to the anomalous divergent circulation. The\nupward branch of this circulation coincides with the region of\nenhanced convection and the subsiding branch extends from the\nAmazon Basin eastward to the Atlantic.\n1.2.2 Australian Monsoon (Wang, Mo)\nA study was completed that examined relationships among\nthe Australian monsoon, equatorial intraseasonal oscillation,\nand Asian cold surges during the past five Northern Hemisphere\nwinters. The data included twice daily wind, temperature, and\nhumidity from the NMC/Global Data Assimilation System. The\nresults indicate that the monsoon activities are modulated by\nthe Madden Julian oscillation and can be classified into two\ncategories. The first is when equatorial intraseasonal oscilla-\ntions are strong and regular (e.g., during the 1988-1989\nwinter) the monsoon is strong and has clear breaks and few\nepisodes (figure 4) The second is during an ENSO winter or\nwhen the SSTs are above normal in the western Pacific (e.g.\nduring the 1990-91 winter); intraseasonal oscillations are\nweaker, there is one monsoon onset, and the breaks are weak and\nbrief (figure 5)\nResults also showed that Asian cold surges have an impact\non the onset of the monsoon, only when the major events are in\nphase with the Madden Julian oscillation. The major cold surge\nevents are, in general, accompanied by an increase of moisture\nconvergence and convection upstream over the Singapore-Borneo\nregion. The convection moves downstream as a part of the intra-\nseasonal oscillation and strengthens the local Hadley cell. As\na result, the Australian subtropical jet grows stronger and\nshifts poleward. Then, baroclinic eddies increase and the upper\nlevel equatorial easterlies extend to Australia. This activity\nis usually followed by intense monsoon rainfall.\n5","DIVERGENCE\n90N\nof\nO.\n60N\n0.\n0.\n2\n30N\n2\nG2\nEQ\n2\n30S\n0\n60S\n0.\n-0.\n90S\n180W 150W 120W 90H 60W 30W OE 30E 60E 90E 120E 150E 180E\nWarm minus cold phase 200 mb divergence difference\nFigure 3a:\nfrom analyses for JFM. Contour interval 1.E-06/sec.\nSTREAMFUNCTION\n90N\n0\n60N\nB\n10\n10.\n8\n0\n401\n0\n30N\n3\nN:\n10.\n10\n20.\nEO\n30S\n(10)°\n0\n60S\n90S\n120E\nOE\n30E\n60E\n90E\n150E\n180E\n180W\n150W\n120W\n90W\n60W\n30W\nCONTOUR INTERVAL 5.00\nWarm minus cold phase 200 mb asymmetric stream-\nFigure 3b:\nfunction difference for JFM. Contour interval is\n1.E+07m*m/sec.\n6","5 DAY MEAN PRECIPITATION (MM/DAY)\n5S-15S\nNOV87-MARB8\n3\n246\n702\nG\na\n15\n9\n12\n1.2\na\nV\n15\nm\n(31)\nTO\n18\n21\n24\n149\n8\n506\nof\n27\n10.0\n0\n30\nGOE\n90E\n120E\n150E\n180\nCONTOUR FROM 0.00000 TO 97.500 CONTOUR INTERVAL OF 2.5000 P113.31= 11.173\nFigure 4 :\nHovmoller diagram for pentad mean precipitation\naveraged over 5S-15S (Nov. 1, 1987 to March 31, 1988)\nfrom GPCP. Also shown is the zonal wind at sigma\nlevel 1, averaged over the box (110E-140E, 5S- 15S).\n7","5 DAY MEAN PRECIPITATION (MM/DAY)\nNOV90-MAR91\n5S-15S\n329\n3\n90\n0\n9\n12\n518\nBl\n15\nIT\n18\n8\nD\n21\n24\n27\nC\n0\n$94\n.072\nto\n30\n150E\n180\nGOE\n90E\n120E\n2.5000\nP113.31= 8.0424\nCONTOUR FROM 0.00000\n10 97.500\nCONTOUR INTERVAL OF\nSame as figure 4, but for the winter of 1990-91.\nFigure 5 :\n8","1.2.3\nClimate Model Diagnostics\n1.2.3.1 Global Data Assimilation System (Mo, Wang)\nA diagnostics study was performed (July 1991 case) to\nassess the impact of horizontal resolution on the Global Data\nAssimilation System (GDAS) . Two assimilation processes were run\nusing identical observed data. The first set was obtained from\nthe current operational GDAS, with a horizontal resolution of\nT126. The second set was obtained using the same model, but\nwith a horizontal resolution of T62. A comparison was then made\nbetween the 2 data sets. Results showed that for the rotational\npart of the flow (e.g., 500 mb height or 200 mb streamfunction) ,\nthe differences in both patterns and magnitudes in the Northern\nHemisphere are small (figure 6) However, larger differences\noccur over the tropics and the southern Indian Ocean, where the\nT62 model underestimates ITCZ-associated divergent circulation\nby at least 25% and produces a weaker Hadley circulation.\n1.2.3.2 MONEG Experiments Using the NMC MRF Model (Mo)\nTwo sets of experiments were performed in this study.\nThe first set consisted of 90 day forecasts with sea surface\ntemperature anomalies (SSTA) updated daily during the entire\nintegration. For the summer of 1987 and 1988, SSTA experiments\nwere made using different initial conditions centered on June 1,\nseparated by one day. The second set of experiments used the\nsame initial conditions; however, the integrations were\nperformed using SST from climatology (CSST). The results showed\nthe SSTA experiments to be more skillful. A comparison was\nthen made between simulated monthly ensemble mean rainfall from\nthe SSTA experiments and satellite estimates of precipitation\n(from the Global Precipitation Climatology Project).\nThe results from this comparison showed good overall\nagreement (figure 7a-d). Two centers of maximum rainfall, over\nthe Arabian sea and the Bay of Bengal, are well simulated;\nhowever, the model failed to capture the movement of the\nrainfall associated with the Indian monsoon. The model did\nsimulate the interannual variability of rain over India and the\nSahel; although, the simulated convection in the central Pacific\nassociated with the 1987 warm episode is not realistic. The\nresults also indicate that when the model is able to simulate\nthe convection associated with the SSTA's, then the updated SSTs\nhave a large positive impact on tropical seasonal forecasts.\nThe impact on the extratropical forecasts is, in general, small.\n9","vp ( t62-t126) lev 12 jul91\n90N\n0.4\n0.2\n0.2\n3\n0.4\n0.2\n0.6\n60N\n<0.4\n0.8\n0.2\n-0\n0.2\n0\n8\no\n-0.2\n30N\n0\n0.4\n-0.4\n0\n-0.6\n0.8\nC\n0.2\n-0.6\nX\n0.4\n0.2\nC.0\n:0.6\n-0\nEQ\n-0.2\n45\n12\n-0.2\n-0.8\n0.4\n-0.4\n-0.2\n0\nC\nD\n-0.4\n1.2\n0\n-0.6\n0.8\n0\n-0.2\n30S\n-0.2\n-0.4\n-0.6\n0\n-0.2\n0.4\n0.2\n0\n0\n60S\nD\n-0.4\n0\n0.2\n0\n90S\n120W\n60W\n0\n120E\n180\n60E\n0\nFigure 6: Difference of analyzed velocity potential difference\nat the sigma level 12 for July 1991 between T62 and\nT126 model. Contour interval is 0.2E+06m*m/sec.\n10","RAIN MM/DAY\nS87\n40N\nB\n20N\nB.\nB.\n16\nEQ\n20S\nB.\n4DS\n40W\n20W\nDE\n2DE\n4DE\n60E\nBDE\n100E\n12DE\n140E\nCONTOUR INTERVAL=\n4.00\nFigure 7a:\nSeasonal mean rainfall for JJA 1987 from GPCP.\nRAIN MM/DAY\nS88\n40N\n2DN\nB.\n16\n0\n16.#\nB.\nB.\nEQ\n2DS\n40S\n40W\n20W\nDE\n2DE\n40E\n60E\nBDE\n100E\n12DE\n14DE\nCONTOUR INTERVAL=\n4.00\nFigure 7b:\nSeasonal mean rainfall for JJA 1988 from GPCP.\n11","S87\nRAIN MM/DAY\n40N\n2.\n2.\n2DN\n05\nB.\n(B'\nB\nEQ\nB.\n20S\n2\n2\n40S\n12DE 14DE\nBOE\n100E\n40E\n60E\nDE\n20E\n20W\n40W\n1.00\nCONTOUR INTERVAL\nFigure 7c: Seasonal ensemble mean rainfall for SSTA 87\nexperiments.\nS88\nRAIN MM/DAY\n40N\n2\n20N\n0\nB.\nB.\nB.\nEQ\nCB.\nB.\n20S\n2\n2\n40S\n100E\n120E\n140E\n20E\n40E\nSDE\nBDE\n4OH\n20W\nDE\nCONTOUR INTERVAL=\n1.00\nFigure 7d: Seasonal ensemble mean rainfall for SSTA 88\nexperiments.\n12","1.2.4 Tropical Convection/Atmospheric Circulation (Kousky)\nA collaborative study (with visiting scientist M. Kayano,\nINPE) was initiated to determine the principal atmospheric\ncirculation (250 mb) and related deep convection (OLR) modes in\nthe South American sector. These modes were computed using\nrotated combined principal component analysis, which enables\ncomputations based on more than one variable. The time series\nwas filtered to isolate variability on intraseasonal and inter-\nannual time scales. The resulting modes show physically\nconsistent relationships between the selected variables. As one\nwould expect, the lowest order modes (as shown in figure 8) are\nclosely related to the Southern Oscillation and intraseasonal\n(30-60 day) oscillations. The analysis was performed using all\nseasons together and cool and warm seasons separately.\nThe resulting patterns display certain seasonal aspects\nof the Southern Oscillation. The first mode (figure 8a), for\nthe low-pass filtered case in which intraseasonal oscillations\nhave been removed, describes variability associated with the\nSouthern Oscillation. The major OLR anomalies, for positive\namplitudes of this mode, agree with the precipitation anomaly\npattern over South America for warm episodes. This mode shows\nvery little seasonality (figure 9a). The second mode (see figure\n8b), also related to extremes in the Southern Oscillation, shows\nstrong seasonality with the largest positive and negative\namplitudes occurring during March - May (figures 9b and 9c).\nThis mode focuses on a regional feature of the effects of\nPacific warm and cold episodes; i.e., circulation and rainfall\nover northern and northeastern South America.\n1.2.5 Oscillatory Modes Flow Regimes (Mo)\nIn a joint study (with M. Ghil, UCLA) , oscillatory modes\nin the interannual frequency band for the Northern Hemisphere\nwere examined, based on monthly mean 700 mb height data from\n1949-1990. Singular spectrum analysis of the leading principal\ncomponents of these data revealed two dominant modes. One is a\nquasi-biennial (QBO) mode with a period near 32 months; the\nother is a low frequency (LF) mode with a period of about four\nyears. Weaker oscillations with periods of 22, 10 and 6 months\nwere also found. The time series associated with the QBO mode\nshows a long interval of strong activity from 1954 to 1966\n(figure 10a) After that, the oscillation became irregular in\namplitude. The LF mode (figure 10b), which is closely linked to\nENSO variability, does not appear to be phase-locked with the\nannual cycle. During strong warm ENSO events, the extratropical\nQBO and LF modes are both amplified and in phase with each\nother.\n13","20X\nBCH\nand\n,\nEU\n(a)\n485\nSOS\nTV\n40W\n26W\nTOOW\nOLR/250 MB VECT WIND PATTERN FOR ANNUAL EOF0701 (VLF)\n40%\n201\nION-\nED\n(b)\n20N\nTYLY\nBOW\nAre\nOLR/250 MB VECT WIND PATTERN FOR ANNUAL EOF0702 (VLF)\nCombined rotated outgoing longwave radiation and 250\nFigure 8 :\nmb vector wind patterns, using the entire calendar\nyear, for a) EOF-1, and b) EOF-2. OLR loadings are\ncontoured with negative values shaded.\n14","PC01 FOR FILTER (N=64) R=07\n(a)\nPC02 FOR FILTER (N=64) R=07\n(b)\n1.0\n1.0\n0.5\n0.5\n0.0\n0.0\n-0.5\n-0.5\n-1.0\n-1.0\n00\n81\n02\n03\n84\n05\n06\n07\n88\n89\n80\n81\n82\n83\n84\n85\n86\n87\n88\n09\nYEARS\nYEARS\nVARIANCE FOR PC02 TIME SERIES (VLF ANNUAL R=07)\n(c)\n0.4\n0.3\n0.2\n0.1\n0.0\nI\n13\n25\n37\n49\n61\n73\nPENTADS\nFigure 9 :\nAmplitude time series (a) and (b) for the first two\ncombined rotated modes shown in figure 8.\nVariance\nof the principal component time series for EOF-2, as\na function of pentad (c) .\n15","a)\n0.4\n0.2\n0.0\n-0.2\n-0.4\n52\n54\n56\n58\n60\n62\n64\n66\n68\n70\n72\n74\n76\n78\n80\n82\n84\n86\n88\n90\nYear\nFigure 10a: Standardized temporal principal components 1 and 2\nassociated with the QBO mode.\nb)\n0.4\n0.2\n0.0\n-0.2\n-0.4\n52\n54\n56\n58\n60\n62\n64\n66\n68\n70\n72\n74\n76\n78\n80\n82\n84\n86\n88\n90\nYear\nFigure 10b: Same as figure 10a, but for LF mode.\n16","1.2.6 Extratropical Circulation (Bell)\nA study was initiated to document the structural\nevolution of low frequency (periods greater than 30 days) and\nmedium frequency (periods of 10-25 days) fluctuations during the\nevolution of blocking episodes. A major blocking episode,\nwhich persisted from March-June 1991 over the South Pacific\nOcean, was examined. Preliminary results suggest that height\nfield variability in the vicinity of the mean block position,\ncentered near 60°S, 120 o W (figure 11c), is dominated by low\nfrequency fluctuations (figure 11a, b, d). These low-frequency\nfluctuations account for a significant portion of the total\nheight anomaly in the vicinity of the block during May and June,\nthe time of maximum block intensity (figure 12a, b). . The height\nfield variability, both upstream and equatorward of the mean\nblock position, is dominated by medium-frequency fluctuations\n(figure 11e); whereas, high-frequency fluctuations (periods of\n2-6 days) contribute little to the observed height field\nvariability in vicinity of the block (figure 11f).\n17","ST. DEV. ABOUT MEAN ANOMALY- AMJ\nST. DEV. OF MEAN ANDM. WRT CLIMO: - AMJ\nST. DEV. WRT CLIMO: 500 MB ANOMALY- AMJ\n/\n180\n28\nD\n180\nao\n60\nL\n80\n80.\nBiO\n120\n1/20\n120\n0°\n20\n20\n60\n60\nb\nEXP. VAR. 1 2-6 DAY FLUCTUATIONS- AMJ\nEXP. VAR.: >30 DAY FLUCTUATIONS- - AMJ\nEXP. VAR. 10-25 DAY FLUCTUATIONS- AMJ\n20J\n1\n20\n20\n40\n20\n20\n20\n20\n20\n2D\n20\n120\n20\n0\n48\n20\n20\n0\n20\nx\n40\n20\nO\n420\n040\n$\n20\n20\nX20\n20\n20\n20\n20\n20\n20\n20\n20\n207\nFigure 11: Southern Hemisphere - (a) Standard deviation from\nclimatology (interval is 30 m) of the 500 mb height\nanomaly field during AMJ 1991; (b) standard\ndeviation (interval is 30 m) of the 500 mb height\nfield from the AMJ mean height anomaly field; (c)\nmean AMJ height anomaly field (absolute values\nreflect the standard deviation of the mean AMJ height\nanomaly from climatology). Percent of variance\n(interval is 10%) in (b) explained by fluctuations\nhaving periods (d) greater than 30 days, (e) between\n10-25 days, and (f) between 2-6 days. Shading\nidentifies regions in which explained variance\nexceeds (d,e) 40% and (f) 25% (shaded values identify\nregions in which explained standard deviation\nexceeds 63% and 50%, respectively). Anomalies are\ncomputed from the 1979-1988 base period.\n18","TOTAL ANOMALY: ( 120.0W 9 60.0S )\nTOTAL ANOMALY\n500.0\n500.0\n400.0\n400.0\n300.0\n300.0\n200.0\n200.0\n100.0\n100.0\n0.0\n0.0\n-100.0\n100.0\n-200.0\n200.0\n-300.0\n300.0\n2\n3\n4\n5\n6\n7\n8\nMONTH\nTOTAL ANOMALY: ( 20. OW 9 60.0S )\n30 - -DAY LOW-PASS - FILTER\n500.0\n500.0\n400.0\n400.0\n300.0\n300.0\n200.0\n200.0\n100.0\n100.0\n0.0\n0.0\n-100.0\n100.0\n-200.0\n200.0\n-300.0\n300.0\n2\n3\n4\n5\n6\n7\n8\nMONTH\nFigure 12: Time series of (a) 500 mb height anomaly (meters) and\n(b) the contribution to the 500 mb height anomaly\nfield by fluctuations having periods >30 days\n(meters) for the period April-July 1991 over the\nmean block position (120° W, 60°S). .\nAnalyses are\nbased on daily 0000 UTC height data and anomalies are\ncomputed with respect to the 1979-1988 base period.\n19","THIS PAGE INTENTIONALLY LEFT BLANK\n20","2. CLIMATE MONITORING\n2.1\nSurface Climate\n2.1.1\nSurface Climate Anomalies (Halpert, Ropelewski, Garrett)\nNew global temperature and precipitation normals were\ncomputed for the 1961-1990 base period. Comparisons were made\nbetween the new mean temperatures and those from the 1951-1980\nperiod. Preliminary results reveal that the 1961 - 1990 base\nperiod mean temperatures are generally higher than the 1951-1980\nmean temperatures (figure 13) However, large differences do\noccur between regions and even between seasons.\nIn another task, comparisons were made between CLIMAT\ndata and monthly summary values (computed by CAC). Results, so\nfar, show that the monthly temperature values are 0.5 - 1.09\ngreater than the CLIMAT values, with the largest differences in\nAfrica and Southeast Asia. This task will continue in an effort\nto determine the cause of these differences.\nCAC staff participated (with other NOAA scientists) in\nmeetings to help develop the Global Climate Perspectives System.\nThis system will enable NOAA to place local-to-global scale\ntemperature and precipitation anomalies in century-scale\nperspective. Also, plans were established for a global drought\nmonitoring system and for the coordinated development and\nimplementation of an integrated software and hardware system.\n2.1.2 Normalized Difference Vegetation Index (Halpert, Schultz)\nThe satellite-derived Normalized Difference Vegetation\nIndex (NDVI) continues to be used as a climate monitoring tool.\nNormalization techniques were tested to try to eliminate the\nbias in the NDVI, which is caused by sensor degradation and\norbital drift. Figure 14 shows a time series of the NDVI for\n1986 - 1989 in a 3° latitude by 6° longitude area in Iowa.\nAlthough a severe drought affected this area during 1988, the\npeak values (week 30) for the index during 1988 and 1989 appear\nsimilar (figure 14a). However, after the NDVI values were\nnormalized by the mean of the first 12 weeks of the year, the\n1988 peak values appear significantly lower than in 1989 (see\nfigure 14b).\nIn a related task, a diagnostic study is being performed\non six years of historical NDVI data. The first harmonic has\nbeen fit to vegetation data for the United States during 1986 -\n1988. Difference maps between the years indicate that the\nannual cycle of vegetation during 1986 and 1987 was about 10-20%\ngreater than during 1988 in the drought-stricken Midwest.\n21","100E\n0.2\n806\nPIZBE\n0.0\n0.2\n0.4\na\n2\n0.\n2\n0.4\n/\n0.2 0\n2\n191\nBOE\n140E\n0.0\nthe\n10.0\n0\n0\n0.21\nQ\n0.2\n0.0\n0.\n0.0\n-0.\n0.2\n0.\nL\nX\nx\n0.0\n0.0\n0.2\n0.0\n40E\n0,0\n160E\n0.2\nit\n8\n0.0\n0\n2\nL.\n0.2\n0.2\nH\n0.\nA\n-0.4\n0\n4\n0\n6\n0\n0.1\nx\n0.2\nK\n0.2\nH\n0.0- -0.2\n0.0\n0,\n0\nH\nH\nCo\n0\n-0.2\n0\n2\n0.0\nH\n0.4\n0.0\n20E\n0\n180\n0.0\n&\n+\nH\nEM\n0.2\nat\n0\n+\nD\n2\n180\n0.2\n0.2\nLOTO\nRG\n0.0\n-0\n2.0.2\n0\no\n2\n0.4\n+\n4\n0.4\nD\nH\nto\nH\n-0.2\n0.2\nM\n0.0\n0.41\n0.0\n160W\n2\nH\n0.0\n0.00\nx\nx\n0.0\n0.2\n0\n0.0\n0.0\nQ\n0%0 but 0.0\nx\nx\nQ\n20W\n140W\nof\nx\nX\n0.2\n0\nU\n0.\n00\n40M\n120W\n0.\n0.00\n0.0 0.0\n60%\n100%\n80W\nTEMP DIFFERENCES (1961 - 1990) - ( 1951 - 1980)\n9999\nFigure 13 : Northern Hemisphere temperature differences between\nthe 1961 -1990 - and the 1951-1980 base periods for the\nMAM season. Contour interval is 0.2°C with negative\ncontours dashed. Positive differences indicate that\n1961-1990 base period means are greater than the\n1951-1980 means.\n22","0.6\n0.5\n0.4\n0.3\n0.2\n0.1\n0\na\n40\n50\n60\n20\n30\n0\n10\nWeek\n0.6\n0.5\n0.4\n0.3\n0.2\n0.1\n0\n-0.1\n0\n10\n20\n30\n40\n50\n60\nb\nWeek\n86\n87\n88\n89\nFigure 14: (a) Time series of the NDVI for the years 1986 - 1989\nand (b) normalized by the mean of the first 12 weeks\nof data for each year. Data are spatially-averaged\nover an area from 41°N-43°N and 92°W-97°W and are\nsmoothed with a four point median filter.\n23","2.1.3 Snow/Ice Monitoring (Ropelewski, Garrett)\nWeekly snow cover data (from NESDIS) were reprocessed for\nthe 1973-1990 period to provide a temporally consistent set of\nweekly and monthly data. A study was then initiated to\ninvestigate the relationships of large - scale seasonal\ntemperature anomalies and snow cover. Preliminary analysis (see\nfigure 15) indicates that for the last half of the\n1980's,\nNorthern Hemisphere positive temperature anomalies were\nassociated with snow cover deficiency at the southerly\nboundaries of the largest temperature anomalies.\n2.1.4 Climate Assessment (Halpert, Ropelewski)\nA comprehensive decadal review was produced and\npublished, which contains numerous surface and atmospheric\ncirculation parameters for the 1981 - 1990 period. These\nparameters include decadal summaries of surface temperature,\nprecipitation, snow and ice, tropospheric temperatures,\nteleconnections, and ozone. In addition, there were summaries\nof significant meteorological events, such as the Southern\nOscillation and extreme temperature and precipitation events.\nFigure 16 is an example of the type of figure contained in the\nreview. In this analysis, surface temperature anomalies for the\n10-year period were computed for both warm and cold seasons in\neach hemisphere. One can see, from this figure, that the\nmajority of the above normal temperatures occurred in the\nDecember-May season in the Northern Hemisphere.\n2.1.5 Diagnostic Studies of the Coupled Ocean-Atmosphere\nSystem (Chelliah, Smith, Ropelewski)\nA diagnostic study was initiated to compare sea surface\ntemperature (SST) data from the COADS data set and CAC's\ndatabase. The main purpose is to show how these 2 datasets\ncompare over the data-rich and data-poor regions of the tropical\nPacific. The CAC blended SST (from 1982 to the present) is\nbased on ship reports, drifting buoys and satellite data, while\nthe COADS based SST (historical record) is based only on exist-\ning ship reports. The analysis period is from 1982 to 1987 and\nthe domain is the tropical Pacific (20°N - 20°S, 120°E - 80°W).\nFor both data sets, monthly anomalies were computed using the\nsame monthly COADS based climatology. Rotated principal\ncomponent analysis was performed on both data sets.\nFigure 17 shows the time series and the spatial loading\npatterns for the leading two principal components of the COADS\nbased SST analysis. Figure 18 is same as figure 17, except for\nthe blended SST analysis. The explained variances of each of\nthese modes is given at the top right hand corner of the corre-\nsponding loading functions. Overall, it appears that the\n24","DD\n<-1. 0\n<-0.5\n-1.0\n0.54\n<1.0\n1.0\n(a)\n(b)\nFigure 15: Northern Hemisphere, December to May surface\ntemperature anomaly for the period 1981 to 1990 (a)\nSchematic of Northern Hemisphere snow cover anomaly\nfor the same period (b)\n.\n25","Dec - May\nJun - Nov\n0\ne-1.0\n-1.0\n<-0.5\n0.5\n1.0\n1.0\nDec - May\nJun - Nov\n50\ne-1.0\n-1.0\n<-0.5\n0.59\n<1.0\n1.0\nFigure 16: Decadal (1981-1990) mean surface temperature season anomaly (left)\nfor the December through May analysis is\npatterns November season (right) . The surface\nand based June on - station data over land and for station sea data\nover water. Anomalies from the\ntemperature the 1951-1980 base period, and signs\nare from climatology over water. The\nSmall plus\nCOADS/ICE data locations over land. dashed.\nindicate interval is 0.5°C with negative anomalies\ncontour\n26","PCA - COADS SST MON. ANOM. TIME SERIES-\nROT MODE # I 14\nROT MODE # 2 /4\n1200\n500\n1000\n400\n800\n300\n600\n200\n400\n100\n200\nC\n0\n-200\n-100\n-400\n-200\nof\n-600\n-300\n-800\n-1000\n-400\n-1200\n-500\n1982\n1983\n1984\n1985\n1936\n1987\n1982\n1983\n1984\n1985\n1996\n1987\nYEAR\nYEAR\nCOAD (1982-87) P. EOF ANALYSIS MODE\n1\n30 ) %\n20N\n-.20\n0\n.40\n40\n10N\n20\n60\n.60\n40\n11\nEQ\n0\n80\n20\n10S\n60\n.80\n20\n.40\n60\n40\n40\n40\n20\n20S\n120E\n140E\n150E\n180\n160W\n140W\n120W\n100W\nBOW\nCOAD (1932-87) P. EOF ANALYSIS MODE\n2\n10%\n20N\na\n20\n20\n10N\n.60\n40\n20\n.40\nEQ\n0\n0\n0\n10S\n-.20\n20\n.20\n0\n20S\n120E\n140E\n160E\n180\n160W\n140W\n120W\n10CW\nBOW\nFigure 17: The time series and the spatial loading patterns for\nthe two leading principal components of the COADS\nbased monthly SST anomalies from 1982 to 1987.\n27","PCA - -BLENDED SST MON ANOM. TIME SERIES-\nROT MODE # 2 /5\nROT MODE # 1/5\n500\n1200\n1000\n400\n800\n300\n600\n200\n400\n100\n200\n0\n0\nY\n-200\n-100\n-400\n-200\n-600\n-300\n-800\n-400\n-1000\n-500\n-1200\n1982\n1083\n1984\n1985\n1986\n1987\n1987\n1982\n1963\n1984\n1985\n1386\nYEAR\nYEAR\nSST - (1982-87) R ECF ANALYSIS MODE\n1\n29%\n20N\n0\n40\n0\n20\n60\n10N\n20\n40 60\nEQ\nEO\n80\n20\n10S\n60\n20s\n120E\n140E\n160E\n180\n160W\n14CM\n120W\n10CW\nBOW\nSST - (1982-87) R ECF ANALYSIS MODE\n2\n15%\n20N\n20\na\n20\n10N\n.40\no\n.20\no\n80\nEQ\n.20\n.60\n10S\n.40\n20\n.20\n.20\n0\n.20\n0\n40\n20S\n120E\n140E\n160E\n180\n:50W\n140W\n120W\n100W\nBCW\nFigure 18: The time series and the spatial loading patterns for\nthe two leading principal components of the CAC\nblended monthly SST anomalies from 1982 to 1987.\n28","leading two eigenmodes, which are associated with the two warm\nENSO events in the tropical Pacific, correspond respectively\nto each other. However, it is striking to see that there are\nvery large differences between the two SST's (especially over\nthe data-sparse eastern Pacific) in even the leading eigenmodes.\nAn examination of the time series and the spatial loading\npatterns beyond the second mode (not shown) indicates that there\nis very little agreement between the two SST's. A preliminary\nconclusion is that the SST variability in COADS data set is only\ngood enough to analyze the low-frequency ENSO time and space\nscales over the data-rich regions.\n2.2\nClouds and Precipitation\n2.2.1\nGlobal Precipitation Climatology Project (GPCP)\n2.2.1.1 Geostationary Satellite Precipitation Data Center\n(Janowiak)\nThe NMC/Climate Analysis Center was designated as the\nAlgorithm Intercomparison Center for an experiment that was\ndesigned to determine the accuracy of satellite-based rainfall\nestimation techniques. This study was conducted over Japan\nduring June - August 1989. High-resolution infrared and visible\ndata from the GMS geostationary satellite (hourly) and microwave\ndata from the U.S. Defense Meteorological Satellite Program\n(DMSP) spacecraft (twice daily) were sent to each algorithm\ndevelopment group. All of the groups were required to submit\nestimates of monthly rainfall accumulation for specified 1.25 o\nlatitude-longitude squares. A validation data set (composite\nof radar estimates and 1300 automated raingauges) was then\nassembled by the Japanese Meteorological Agency. This data set\nwas not sent to any group until their rainfall estimates were\nreceived by the validation center.\nA statistical plot, used to evaluate the remotely sensed\nprecipitation estimates against the validating observations\n(June 1-30 1989), is shown in figure 19. The figure shows\nestimates of error, correlation (time and space mixed), and\n\"percent correct\"; that is, the percentage of correct estimates\nas computed from a 4 category contingency table. Figure 20\nshows the intercorrelation among estimation methods for both\nobserving periods and is useful in determining the similarities\nand differences among the techniques. Initial results indicate\nthat the majority of the infrared-based techniques yield similar\nresults. There is some evidence that techniques which use\nvisible data in conjunction with infrared data yield more\naccurate estimates. Microwave-based algorithms seem to yield\npromising results for \"instantaneous\" cases; but, for daily or\nmonthly estimates, they suffer from temporal sampling problems\ndue to the polar orbit of the satellite.\n29","IR Algorithms Daily Rainfall Statistics\nover ( Land & Ocean ) in ( June ) Period\n0.7\n12\n10\n0.6\n8\n0.5\n6\n4\n0.4\nLEGEND\n2\nMean Error\nRoot Mean Squore Error\nCorrelation Coefficient\n0\nPercent Correct/100\n0.3\n-2\n0.2\n-4\nFigure 19: Statistics of comparison between IR and IR/VIS\nalgorithm estimates and validation data for June 1-\n30, 1989.\nJuly-August Period\nJune Period\nAMeDAS-Rador\nAust/BMRC/CST\nAust/BMRC/NAWT\nAust/Curtin\nBristol/climate\nBristol/CST\nBristol/model\nBristol/SSMI\nCanada/control\nConado/Gorond\nCanada/roinsot\nChina/Wu\nGPI\nJMA/Oosawa\nNASA/CST\nNASA/CST_odj\nNASA/GPI_odj\nNASA/NAWT\n0.7\n0.8\n0.9\n1.0\n0.3\n0.4\n0.5\n0.8\nFigure 20: Inter-correlation among infrared and infrared/visible\nalgorithm estimates for both observing periods.\n30","2.2.2 Tropical Rainfall (Janowiak)\nA comparison was made between 5-day accumulations of\nsatellite-derived tropical rainfall estimates (GPI) and precipi-\ntation forecasts from the NMC Medium Range Forecast (MRF) and\nECMWF models. Comparisons of mean rainfall from March -\nNovember 1989 show that the satellite estimates and the model\nforecasts agree reasonably well, except in the northern Indian\nOcean and the Pacific ITCZ regions (figure 21) . Zonal-mean\nrainfall for land only, ocean only, and combined (figure 22)\nindicates reasonable agreement among the data sets, except over\nland from 10N-10S where all 3 data sets substantially disagree.\nTemporal correlations (from 54 five-day periods) indicate\nno statistically significant association between the model\nforecasts and the satellite estimates in much of the tropical\nbelt as depicted in figure 23. These low correlations\napparently reflect the inability of the models to characterize\n30-60 day bursts of convection that are often seen in the\ntropics. To demonstrate this, figure 24 shows the time series\nof spatially-averaged rainfall forecasts and estimates for a\nlocation where there is a low correlation between the model\nforecasts and satellite estimates.\nAtmospheric Circulation\n2.3\n2.3.1 Tropospheric Variability (Kousky, Mo)\nA study was initiated to investigate the principal global\nmodes of anomalous upper tropospheric stream function. A pentad\narchive (from NMC analyses) served as the basis for this study,\nwhich enables the examination of variability on intraseasonal to\ninterannual time scales. Preliminary results indicate that the\nlowest modes describe the spatial and temporal variability\nassociated with extremes in the Southern Oscillation. Research\nis continuing concerning the interpretation of higher modes of\nvariability in both hemispheres.\n2.3.2 Tropospheric Anomalies (Janowiak, Kousky, MO)\nAn archive of zonally-averaged temperature (monthly\naveraged in time) for each discrete pressure level in the\nClimate Diagnostics Data Base (CDDB) was produced to monitor\npossible temperature fluctuations associated with the volcanic\neruption of Mt. Pinatubo, Philippines. Although the time series\nbegins in October 1978, it contains several discontinuities that\ncoincide with changes in NMC's Global Data Assimilation System.\nHowever, this information may still be useful to detect possible\ntemperature trends by comparing current values with past ones.\n31","NOAA Coral Gables Library Center\n1320 South Dixie Highway, Room 520\nCoral Gables, Florida 33146\nGPI\n40N\n5\n2\n6\n6\n2 2\n2\nU\n5\n5\n?\n20N\n0\nA\nEQ\n20S\n52 2\n.5\n.5\n5\n6\n66 6\n2.5\n5266\n2.5\n40S\n20E\n60E\n100E\n140E\n180\n140W\n100W\n60W\n20W\nI\nMRF\n40N\n52286\n6525\n2\n5\n82\n2.5\n20N\n10\n0\nOR\nEQ?\n6\nill\n20S\n50\n22\n2\n5\n66\n2\n522\n2\n2\n40S\n20E\n60E\n100E\n140E\n180\n140W\n100W\n60W\n20W\n0\nECMWF\n40N\n666\n22\n22\n2\n2\n2\nU\n60\n20N\nO\n6\n0\n0\nE02\n-\n20S\n222 2\n2\n22\n2\n40SH\n20E\n60E\n100E\n140E\n180\n140W\n100W\n60W\n20W\nFigure 21: Mean rainfall (mm/day) for the March 7 - December 1,\n1989 period from the satellite - based estimates\n(GPI) , the NMC (MRF) model, and ECMWF model\nprecipitation forecasts.\n32","ZONAL MEAN RAINFALL(land + ocean): MAR 7 - DEC 1, 1989\n26.25\nso\nD = ECMWF\nO MRF\n21.25\n40\nGPI\n16.25\n11.25\n6.25\n1.25\n-3.75\n-8.75\n-13.75\n-18.75\n-23.75\n-28.75\n0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n10.0\nMM/DAY\nZONAL MEAN RAINFALL(land only):\nMAR 7 - DEC 1, 1989\n26.25\nD = ECMWF\n21.25\nO MRF\n= GPI\n16.25\n11.25\n6.25\n1.25\n-3.75\n-8.75\n-13.75\n-18.75\n-23.75\n-28.75\n0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n10.0\nMM/DAY\nZONAL MEAN RAINFALL (ocean only):\nMAR 7 - DEC 1, 1989\n26.25\nD = ECMWF\n21.25\nis\nC = MRF\nGPI\n16.25\n11.25\ns\n6.25\n1.25\n-3.75\n-8.75\n-13.75\n-18.75\n-23.75\n-28.75\n0.0\n1.0\n2.0\n3.0\n4.0\n5.0\n6.0\n7.0\n8.0\n9.0\n10.0\nMM/DAY\nFigure 22: Latitudinal profile of zonal mean rainfall for GPI\n(solid), MRF (dashed) , and ECMWF (dotted) over the\no\nperiod March 7-December 1, 1989 for each 2.5\nlatitude band from 30°N-30°S (centered in the middle\nof each band) for all locations, land only, and\nocean only. Units are \"mm/day\".\n33","GPI / MRF\n40N\n20N\nEQ\n20S\n40S\n100ET40E180140W100W60W20W\n20E\n60E\nGPI / ECMWF\n40N\n20N\nEQ\n0\n20S\n40S\n140W\n100W\n60W\n20W\n20E\n140E\n180\n60E\n100E\nFig are 23: Temporal correlation at each 2.50 location between\n30°N-30°s on rainfall differences between adjacent\npentads between GPI VS. MRF and GPI vs. ECMWF for the\nperiod March 7-December 1, 1989. Black regions are\nwhere mean rainfall for the period (as determined\nfrom the GPI) was < 1 mm/day and correlations were\nnot computed. The lightly shaded regions indicate\nwhere the correlations are significant at the 95%\nlevel. Areas with no shading indicate no significant\ncorrelation between the GPI estimates and model\nforecasts, and symbols inside these areas are where\nthe correlations are negative.\n34","BOX AVG (90E - 100E, 5N - 2.5S)\nMAR 7 - DEC 1, 1989 (PENT.)\n35.0\no = MRF\n30.0\nA = ECMWF\n= GPI\n25.0\n20.0\n15.0\nA\nA\n10.0\nA\nA\n5.0\n0.0\nAPR\nMAY\nJUN\nJUL\nAUG\nSEP\nOCT\nNOV\nDEC\n1989\nFigure 24: Time series of rainfall in grid box defined by 90° -\n100°E and 5°N-2 - . 5°S for the period March 7-December\n1, 1989 (mm/day) for GPI (solid) , MRF (dashed) , and\nECMWF (dotted) .\n35","Software was developed and implemented that enhances user\naccess to the CDDB and its products. All CDDB fields that\nappear in CAC's Monthly Climate Diagnostics Bulletin are now\nroutinely uploaded to the CAC Dial-Up Data Service. The method\nby which streamfunction, velocity potential and divergence\nvalues are computed for the Bulletin has been changed from grid\npoint calculations to a spherical harmonic approach. Data,\nnecessary for the production of time-longitude plots and index\ntime series, are now routinely transferred to a workstation for\nthe automation of many graphical products.\n2.3.3 Mid-latitude Monitoring Program (Bell)\nThe goal of this project is to monitor and diagnose mid-\nlatitude circulation variability occurring on the intra-monthly\nthrough inter-seasonal time scales. The first step was to\ndevelop a set of prototype indices and diagnostics. Some of the\ndiagnostic tools include: (1) a time series of teleconnection\nindices to monitor the phases of 5 primary Northern Hemisphere\nteleconnection patterns (figure 25) ; (2) an analyses of monthly\n500-mb height variability to identify persistent positive and\nnegative anomalies in each hemisphere (figure 26) ; and (3) an\nanalyses of spectrally-decomposed 500-mb height anomalies to\nmonitor planetary and sub-planetary scale contributions to\nintra-monthly circulation variability in each hemisphere\n(figures 27 and 28) These diagnostics depicted the spatial and\ntemporal evolution of two features (described below) which\nexhibited remarkable persistence during April - June 1991.\nIn the Northern Hemisphere, the 500-mb circulation was\ndominated by a stationary wave-train of large amplitude height\nanomalies extending eastward from North America to north-central\nUSSR (figure 26a, b). A time series of the total anomaly field\n(figures 27a, d) the planetary scale (figure 27b, e) and sub-\nplanetary scale (figure 27c, f) height anomaly fields suggest\nthat the anomalous wave pattern reflected persistent positive\nsub-planetary scale height anomalies that were reinforced by a\nplanetary scale pattern. The analysis also shows that the\nstationary wave pattern represented a major disruption of\ntransient wave activity emanating from the eastern and central\nNorth Pacific (figure 27d). . Finally, the positive height\nanomalies over the USSR reflected the persistent positive phase\nof the Eurasian teleconnection pattern (figure 25e)\nIn the Southern Hemisphere, a major blocking episode began\nin late March and persisted through June. During this event,\npersistent 500-mb height anomalies were concentrated over the\nsouth-central and south-eastern South Pacific and a pronounced\nlack of persistence was noted elsewhere (figures 26c, d) In\ncontrast to the Northern Hemisphere analysis, persistent\nplanetary scale height anomalies dominated the region of the\nblock (figures 28a, b). This block became particularly enhanced\nduring May when positive sub-planetary scale height anomalies\nbecame concentrated over the region (figure 28c).\n36","WEST PACIFIC TELECONNECTION INDEX\nPNA TELECONNECTION INDEX\nDJFMAMJJASONDJFMAM\nDJFMAMJJASONDJFMAMJJ\n2.00\n2.00\n2.00\n2.00\n1.00-\n1.00\n1.00\n1.00\n0.00\n0.00\n0.00\n0.00\na\n-1.00\n.00\n-1.00\n.00\nDJFMAMJJASONDJFMAMJJ\nDJFMAMJJASONDJFMAMJJ\n89\n90\n91\n89 90\n91\nWEST ATLANTIC TELECONNEC ON INDEX\nEAST ATLANTIC TELECONNECTION INDEX\nIDJFMAMJJASONDJFMAMJJ\nDJFMAMJJASONDJFMAMJJ\n2.00\n2.00\n2.00\n2.00\n1.00\n1.00\n1.00-\n1.00\n0.00\n0.00\n0.00\n0.00\nC\n-1.00\n.00\n-1.00\n-1.00\nDJFMAMJJASONDJFMAMJJ\nDJFMAMJJASONDJFMAMJJ\n89\n90\n91\n89 90\n91\nEURASIAN TELECONNECTION INDEX\nDJFMAMJJASONDJFMAMJJ\n2.00\n2.00\nFigure 25: 700 mb teleconnection\n1.00\n1.00\nindices (identified by Wallace\nand Gutzler, J. Atmos. Sci.\n,\n1981, pp. 784 - 812).\nCurves\nshow 25-day running mean values\n0.00\n0.00\nof: (a) the West Pacific (WP)\nindex; (b) the Pacific/North\nAmerican (PNA) index; (c) the\ne\nWest Atlantic (WA) index; (d)\n-1.00\n.00\nthe East Atlantic (EA) index and\nA M A S 0 JFMAMJJ\n89\n90\n91\n(e) the Eurasian (EU) index.\nThe running mean is applied to non-overlapping 5-day averaged\nindex values determined from daily normalized 700 mb height data\nfor the period December 1989 through July 1991. Daily height\nanomalies are normalized using 27-year (1964-1990) daily means\nand standard deviations. Tick marks along horizontal axes are\nplaced at the beginning of each month. Inset illustrates\npositive phase of the teleconnection pattern index, with height\nanomalies over action centers indicated by (+) and (-) signs.\n37","500 MB: PERCENTAGE OF POSITIVE ANOMALY DAYS- AMJ\n500 MB: PERCENTAGE DF NEGATIVE ANOMALY DAYS- AMJ\n25\n25\n25\n25\n50\n25\n25\n50\n5\n25\n5\n50\n$\n25\nPAY\nSTATE\nYO\no\nOC\nI\n25\nCUR\n25\n25\n25\n50\nVS\n3\n25\nso\n5\n>25\n50\n50\na\n5\n25\n25\n50\n25\nOX\n50\n50\nb\na\n25\nn\n500 MB: PERCENTAGE OF POSITIVE ANOMALY DAYS- AMJ\n500 MB: PERCENTAGE OF NEGATIVE ANOMALY DAYS- RMJ\n2\n25\n25\n25\n25\n19\nor\n500\n25\n50\n.\n25\n50\n50\n50\n(50\n2\n50\n25\n50.\n0\n50\n25\n50\nd'\n50\nFigure 26: Percentage of days during April-June 1991 in which\n500 mb height anomalies (a,c) greater than 15m were\nobserved in the Northern and Southern Hemisphere,\nrespectively; and (b,d) less than - 15 m were\nobserved in the Northern and Southern Hemisphere,\nrespectively. Values greater than 75% are shaded.\n38","60N: 500 HEIGHT ANOMALY\nAMJ\nEON: 500 MB HEIGHT ANOMALY WAVES 1-5\nAMJ\nSDN: 500 MB HEIGHT ANDMALY WAVES 7-12 RMJ\n1\n1\n1\n6\n6\n5\n11\n11\n11\n16\n16\n16\n21\n21\n21\nCD.\n26\n26\n26\n31\n31\n31\n35\n35\n36\n41\n41\n41\n46\n46\n46\n51\n51\n51\nHID\n300.\n55\n55\n56\n61\n61\n61\n66\n66\n65\nso:\n71\n71\n71\n76\n76\n76\n&\n81\nE1\n81\n&\n86\n86\n86\nb\nC\n91\n91\n91\n0\n60\n120\n180\n240\n300\n350\n0\n60\n120\n180\n240\n300\n350\n0\n60\n120\n180\n240\n300\n350\n45 N : 500 HEIGHT ANOMALY\nAMJ\n45 N: 500 MB HEIGHT ANOMALY WRVES 1-5\nRMJ\n45 N : 500 MB HEIGHT ANDRALLY WAVES 7-12\nAMJ\n1\n1\n1\n6\n6\n6\n11\n11\n11\n16\n16\n16\n21\n21\n21\n25\n26\n26\n-BOY\nS!NUID\n31\n31\n31\n36\n36\n36\n41\n41\n41\n46\n45\n46\n51\n51\n51\n56\n56\n56\n61\n61\n61\n66\n65\n66\n71\n71\n71\n76\n76\n76\n81\n81\n81\n86\nd\n86\n86\ne\n91\n91\n91\n0\n60\n120\n180\n240\n300\n350\n0\n60\n120\n180\n240\n300\n360\nD\n60\n120\n180\n240\n300\n350\nFigure 27: Northern Hemisphere - Daily 500 mb height anomalies\nfor AMJ 1991 averaged over 10° latitude bands\ncentered at (a)-(c) - 60°N and at (d)-(f) 45 N. Panels\n(a) and (d) show the full 500 mb height field\nanomalies (interval is 120 m) ; Panels (b) and (e)\nshow the planetary scale (two-dimensional wavenumbers\n1-6, zonal mean removed; interval is 60 m) height\nanomalies; Panels (c) and (f) show the sub-planetary\nscale two-dimensional wavenumbers 7-12; interval is\n60 m) height anomalies. Positive height anomalies\nare shaded. Anomalies are computed with respect to\nthe 1979-1988 base period.\n39","605: 500 MB HEIGHT ANOMALY WAVES 7-12 AMJ\n60S: 500 MB HEIGHT ANOMALY WAVES 1-6\nAMJ\n60S: 500 HEIGHT ANOMALY AMJ\n1\n1\n60.\n1\n6\n6\n6\n11\n11\n11\n16\n16\n16\n21\n21\n21\n220\n&\n26\n26\n50\n26\n31\n31\n31\n36\n36\n36\n41\n41\n41\n46\n46\n46\n51\n51\n51\n56\n56\nL80\n56\n(120\n61\n61\n61\n66\n66\n66\n71\n71\n71\n360.\n76\n76\n76\n81\n81\n81\n86\n86\n86\nC\nb\na\n91\n91\n91\n360\n120\n180\n240\n300\n360\n0\n60\n180\n240\n300\n0\n60\n120\n180\n240\n300\n360\n0\n60\n120\nFigure 28: Southern Hemisphere - Daily 500 mb height anomalies\nfor AMJ 1991 averaged over 10° o latitude bands\ncentered at 60°s. Panel (a) shows the full 500 mb\nheight field anomalies (interval is 120 m) ; Panel (b)\nshows the planetary scale (two-dimensional\nwavenumbers 1-6, zonal mean removed; interval is 60\nm) height anomalies; Panel (c) shows the sub- -\nplanetary scale (two-dimensional wavenumbers 7-12; -\ninterval is 60 m) height anomalies. Positive height\nanomalies are shaded in all panels. Anomalies are\ncomputed with respect to the 1979-1988 base period.\n40","Operational Products\n2.4.\n2.4.1 Climate Diagnostics Bulletin (Kousky)\nThe Monthly Climate Diagnostics Bulletin (CDB) was\nenhanced by several new diagnostic products, which depicted\nfeatures of the extratropical Northern and Southern Hemisphere\ncirculation patterns. These additions offer users a more\ncomprehensive and balanced analysis of global anomaly patterns.\nDiagnostic plots of subsurface temperature anomalies and upper\nlayer heat content have also been added to further improve real-\ntime monitoring of oceanic variability in the tropical Pacific.\nThe CDB has also highlighted and will continue to feature the\neffects of the eruption of Mt. Pinatubo in the Philippines,\nnamely the stratospheric aerosol cloud and its dispersal.\nSeveral ENSO Advisories were issued during 1991 as\noceanic and atmospheric anomaly patterns in the tropical Pacific\ncontinued a slow trend toward a warm episode (figure 29a, b)\nLow-level easterlies weakened throughout the equatorial Pacific\nand positive sea surface temperature anomalies of greater than\n1°C continued in the central equatorial Pacific near the date\nline. During the northern spring of 1991, the Southern\nOscillation Index became strongly negative (figure 30) and SST\nanomalies increased throughout the equatorial Pacific. However,\npersistent enhanced convection failed to develop in the central\nequatorial Pacific. There was no further evolution toward a\nwarm episode in June or July; however, August and September 1991\ndata did show some indication.\nSeasonal Climate Review (Diagnostics Branch staff)\n2.4.2\n2.4.2.1 September - November 1990 (MO)\nConditions during the September-November (SON) season\nevolved toward a warm episode in the tropical Western Pacific.\nSea surface temperature (SST) anomalies greater than +1°C were\nfound and the oceanic thermocline along the equator continued to\ndeepen. However, the pool of warmest water remained west of the\ndate line. Tropical convection for the season was normal and\ndid not show any characteristics of a warm episode. Also, most\natmospheric conditions were near normal; although, anomalous\nwesterlies at the 850 mb level were observed over the western\nPacific during November.\nIn the Northern Hemisphere, a Pacific blocking event\noccurred in September and a strong Western Pacific Oscillation\n(WPO) pattern persisted through November. The WPO pattern is\nnoted for the strength of the negative correlation between the\ntwo teleconnection centers located at 60°N/155°E and 30°N/155°E\nand for its broad longitudinal extension at low latitudes.\nDiagnostics suggest that this event may be related to anomalous\nconvection in the Pacific. Above normal temperatures continued\nto occur over much of the land areas.\n41","29.5\n29.5\n2928.5\n2827 527\n26\n25\n24\n23\n2324\n29\nL\n25\n28\n28.\nJAN (89)\n27\n28.5\nA\n29\n29.\n24\n25\n29\n29.5\nJUL (89)\n23\n0\n25\n29\n28.5\nJAN (90)\n26\n29\n27\n1\n29.\nH1\n26\n24\nJUL (90)\n25\n29.\n30\nH\n29\n2025\n25\nJAN (91)\n26\n29\n29.5\n90\n#\n26\n29.5\nJUL (91)\n25\n29\n28.5 2828.5\n29\n29.5\n29.5 2928.28 27.27\n26\n25\n24\n24\n100E\n120E\n140E\n160E\n180\n160W\n140W\n120W\n100W\n80W\n0.5\nto\n0.5\n0.0-0.5\n-2.0\n-2.0\n-2.0\n5\n-0.5\n10.0\n0.0\nJAN (89)\n0.5\n0.5\n0.0\nJUL (89)\nH\n0.5\n-0.5\n4\n-0.5\n0.\n-0.5\nJAN (90)\n0.5\n10.5\n0.0\nM\n0.5\n0,5\n0.5\nJUL (90)\nL\n0.5\n0\n0\n0.0\n0.0\n10.0\n0.5\n0.0\n0.5\nJAN (91)\n0.5\no\n0,5\nH\nJUL (91)\n0.5\n0.0\n0.0\n0.0\n0.0\n0.0\n0.0\n1.0\n0.5\n0.5\n0.5\n0.5\n0.5\n0.5\n80W\n100E\n120E\n140E\n160E\n180\n160W\n40W\n120W\n100W\nFigure 29 : Time-longitude section of a) mean and b) anomalous\nsea surface temperature for the latitude band of 5°N-\nContour interval is 1°C and 0.5°c, respec-\n5°S.\nSST values greater than 28°C and anomalies\ntively.\nless than -0.5°c are shaded. Stippled areas indicate\nanomaly values greater than 0.5°c.\n42","SOI\n3.0\n1.5\n0.0\n1.5\n-3.0\n1 2 3 4 5 6 7 8 9 1011121 2 3 4 5 6 7 8 9 1011121 2 3 4 5 6 7 8 9 1011121 2 3 4 5 6\nSOI FROM JAN 1988-JUN 1991\nFigure 30: Monthly values of the Southern Oscillation Index for\nthe period January 1988 - June 1991.\n43","2.4.2.2 December 1990 - February 1991 (Chelliah)\nThere was no significant change in the seasonal mean\nareal extent of sea surface temperature (SST) in the equatorial\nPacific. This was the case for the 29°C and 30°C isotherm and\nthe 1°C SST anomaly over the western and central sections.\nHowever, along the South American coast, negative SST anomalies\nwere replaced by positive values. On a month-to-month basis,\nthe area occupied by the +1°C SST anomaly (centered on the\nequator and the date line) and its eastward extent started to\ndecrease steadily in January and February from their peak\nDecember values. These changes at the surface are consistent\nwith changes in the upper layer heat content in the Pacific\nbasin and the depth of the 20°C isotherm along the equator. The\nthermocline showed steady signs of deepening in the eastern\nPacific and shallowing in the western equatorial Pacific since\nDecember 1990. Consistent with these SST changes, 850 mb\neasterly anomalies returned to all three index regions in the\nPacific during January and February, for the first time since\nOctober 1989. Also, both the Southern Oscillation Index and the\n200 mb zonal wind index approached near zero values in February.\nFor the season as a whole, much of the Northern\nHemisphere continued to experience above normal temperatures.\nHowever, normal to below normal temperatures occurred over the\nwestern two thirds of the continental United States and Canada.\nDrought conditions continued in the western U. S. particularly\nin California. In contrast, the Gulf Coast states had above\nnormal precipitation. In Europe, both the temperature and\nprecipitation were below their seasonal means.\nIn the Southern Hemisphere, pockets of above normal temp-\neratures were observed in southeastern Africa, coastal South\nAmerica, southern Australia, and for most of Indonesia. Winter\nmonsoon rainfall was deficient, except over northern Australia.\n2.4.2.3 March - May 1991 (Bell)\nMost tropical oceanic and atmospheric indices during\nMarch-May (MAM) 1991 indicated the initial stages of a develop-\ning warm episode. Positive SST anomalies spread throughout\nthe central and eastern equatorial Pacific during April and May,\nresulting in the largest SST anomalies in the east-central\nequatorial Pacific since the 1986-87 ENSO event. These\nincreased SST anomalies were combined with sharp decreases in\nthe SOI. Atmospheric wind indices suggested a reduced strength\nof both the easterly trades and subtropical jet speeds over the\neast-central equatorial Pacific, implying a reduced strength of\nthe Walker circulation. One key feature, generally associated\nwith ENSO events (enhanced convection in the central equatorial\nPacific), was not observed during MAM. Instead, convective\nactivity (as indicated by OLR anomalies) has been near normal\nalong the equator near the date line.\n44","In the Northern Hemisphere, the primary mid-latitude 500-\nmb circulation anomaly shifted from the central North Pacific\n(in March) to the entire Atlantic sector (in April) The mean\n500-mb circulation was then dominated by a wave-train of large\namplitude height anomalies extending eastward from North America\nto north-central USSR. In May, the mean 500-mb height anomaly\nfield reflected primarily an intensification of the April\npattern throughout this region.\nFor the season as a whole, the contiguous United States\nexperienced its third warmest MAM since 1931; while the north-\neastern states had their warmest MAM. Similarly, mean MAM\ntemperatures were the second highest on record for the south-\neastern and Gulf Coast states and the upper midwest. Above\nnormal precipitation was observed in the western United States,\nparticularly during March. Above normal precipitation also\noccurred in the Northern and Central Plains states (April and\nMay) Rainfall along the Gulf Coast was very heavy, with totals\nexceeding the 90th percentile throughout much of the region.\nIn the Southern Hemisphere, a pattern of persistent\npositive height anomalies over Australia was associated with\nabove normal temperatures in southern and eastern portions of\nthe continent. This pattern was also associated with large\nprecipitation deficits throughout Australia, which is consistent\nwith precipitation patterns often observed during warm episodes.\n2.4.2.4 June - August 1991 (Halpert)\nTropical Pacific atmospheric/oceanic indices continued\nto indicate the early stages of an El Niño/Southern Oscillation\n(ENSO) episode. One year ago, sea surface temperatures (SST) in\nthe central Pacific increased to about 1.0°C above normal and\nhave remained anomalously warm. During this season, however,\npositive SST anomalies decreased to near normal in the eastern\nPacific, but remained above normal in the west. Also, weak\nwesterly low-level wind anomalies occurred over the central\nPacific throughout the season. In addition, outgoing longwave\nradiation anomalies over the tropical Pacific were strongly\nnegative (greater than normal convection) during August for the\nfirst time in over a year. This increase in convection may\nindicate that conditions, which prevailed in the Pacific for the\npast year, are now evolving into a significant warm episode.\nOver the Northern Hemisphere, a major blocking pattern\nthat became established over north-central USSR in April\ndissipated in July. Negative height anomalies then prevailed\nthroughout the region for the remainder of the season.\nPersistent positive height anomalies were found over eastern\nSiberia and also over central Canada during JJA. These two\nanticyclonic circulation anomalies were associated with above\nnormal surface temperatures and below normal precipitation.\nElsewhere, positive temperature anomalies were observed over\nmuch of the hemisphere.\n45","In the Southern Hemisphere, the primary circulation anomaly\nfor the past several months has been a blocking episode centered\nover high latitudes in the central and eastern South Pacific.\nThis feature dissipated during July in association with a major\ncirculation change throughout the South Pacific basin. Positive\nheight anomalies over the south-central South Pacific during\nAugust reflected the retrogression of a planetary scale ridge\naxis, whose evolution appears to be independent of the previous\nblocking episode.\n46","3. STRATOSPHERE AND TRACE GASES\n3.1\nField Analysis\n3.1.1 Stratospheric Winds (Long)\nOne of the goals of this project is to derive an accurate\nwind field from CAC's analyzed stratospheric height fields. A\n\"balanced\" wind field has been computed from the height field\nand compares favorably with MRF-analyzed winds at overlapping\npressure levels of 70 and 50hPa. One deficiency found in the\n\"balanced\" wind field is the lack of resolution which prevents\nthe discernment of small scale eddies. However, wind fields\nproduced by the above method are being used to track the ash\ncloud and the movement of stratospheric aerosols from the Mt.\nPinatubo volcanic eruption. Another use of the balanced wind\nfields will be to assess the validity of winds derived by the\nHigh Resolution Doppler Imager (HRDI) instrument on board the\nUpper Air Research Satellite (launched in September 1991).\n3.1.2 ERBE (Yang)\nAn evaluation was made of the new (S-4G) products, as\npart of the NASA/Earth Radiation Budget Experiment (ERBE). The\ndata and documentation were evaluated and suggestions were made\nthat resulted in changes to accommodate computer systems. The\navailability of these S-4G data have proved useful in a joint\nstudy (with D. Kann) on atmospheric energy transport. The\nseasonal energy transport (computed from net atmospheric\nradiation) was compared with the energy transport (calculated\nfrom dynamic fields) Some deficiencies were found over the\ntropics that may be due to procedures in the initialization.\nIn another study, several forecast runs with NMC's global\nmodel have been conducted to investigate the roles of clouds.\nThis work supports the NASA \"First April 1989 Surface Radiation\nBudget Experiment.\" The results were compared with the other\nradiative transfer calculations and substantial differences\noccurred over the tropics. The differences can be attributed to\nthe different treatment of the surface temperature and\nspecification of the optical properties of the low level clouds.\nA new algorithm was developed (with S. Zhou, NRC visiting\nscientist and L. McMillin, NESDIS) to improve the cloud product\nfrom NOAA/TOVS algorithm. An intercomparison between TOVS-\nderived cloud products and cloud datasets has shown that the\nTOVS products substantially underestimate the lowest and highest\nlevel cloud. The new algorithm uses two pilot channels to\ndetermine the approximate cloud levels and then selects the\nproper channels for cloud retrievals. The results have shown\nimprovements and the new algorithm will be tested further with\nthe goal of replacing the current algorithm.\n47","In a joint project (with NMC/Development Division, NESDIS\nand the University of Maryland), the bulk atmospheric longwave\ncooling rates were calculated utilizing NMC archived data for\nthe mid-December 1990 to mid-January 1991 period. The results\nwere compared with those derived from satellite measurements and\nbetter agreement was found for upper layers (250 mb and above).\n3.1.3 Upper Air Intercomparisons (Gelman)\nA number of tests were conducted on radiosonde\ninstruments that are used for NWS operations. An evaluation\n(with NWS personnel at Sterling VA) was made and technical\nreports have been completed. These reports describe the\nprecision and compatibility of the new radiosondes manufactured\nby VIZ Corporation relative to the older model. Results showed\ngood temperature compatibility, but there were differences\nbetween humidity values. Reports are also in preparation\ndescribing test results of Space Data Corporation radiosonde\nprecision and compatibility versus the present VIZ radiosonde.\nResults from this test showed differences in both temperature\nand humidity. Also, a first draft of the Federal Handbook No.\n3, Rawinsonde Observations was reviewed by M. Gelman, as\nChairman of the Ad Hoc Group.\nCAC staff continued to provide technical support and\ninformation to NASA/Houston in connection with Space Shuttle\nlandings. Data from rawinsondes, rocketsondes and NMC analyses\nare used to derive detailed estimates of atmospheric parameters\nfrom 400,000 feet to the surface along the re-entry path of each\nflight. Support was provided for 8 landings during the year.\nOzone/Temperature Trends\n3.2\n3.2.1 Trend Analysis (Nagatani)\nThe joint trend analysis project continues with personnel\nfrom the University of Chicago, University of Wisconsin, and\nLawrence Livermore Laboratories (LLL) Ozone and temperature\ntrends were calculated from monthly-averaged ozonesondes and\nradiosonde temperatures. With the use of an autoregressive time\nseries model, calculated trends from radiosonde temperatures\nwere compared with computed model results from the LLL radiative\ntransfer model. The observed temperature trends indicate a\nsignificant cooling in the upper troposphere and lower\nstratosphere that is in substantive agreement to that projected\nfrom the observed ozone decrease when the ozone decrease is put\ninto the LLL model. Together, the results confirm the existence\nof the lower stratospheric changes which were not anticipated\nfrom traditional gas-phase chemical models. Figure 31a shows\nthe ozone trends, figure 31b shows the calculated temperature\ntrends, and figure 31c shows the computed LLL model trends.\n48","55\n50\nOZONESONDE TREND ESTIMATES\n45\n40\nTHROUGH 1986\n35\n30\n25\n20\n15\n10\n5\no\n-10\n0\n10\n20\n-15\n-5\n5\n15\nFigure 31a: Decadal ozonesonde trend estimates as a function of\nheight. Horizontal lines represent 95% confidence\nlimits. (Units are percent per decade.)\n55\n50\nRAWINSONDE TEMPERATURE\n45\n40\nTREND ESTIMATES\n35\nTHROUGH 1986\n30\n25\n20\n15\n10\n5\no\no\n0.5\n1\n-1.5\n-1\n-0.5\nFigure 31b: Decadal rawinsonde temperature trend estimates as a\nfunction of height. Horizontal lines represent 95%\nconfidence limits. (Units are degree per decade.)\nLLL ESTIMATE OF TEMPERATURE CHANGE\n1970-1986 SCALED TO DEGREE/DECADE\n55\n50\n45\n40\n35\n30\n25\n20\n15\n10\n5\no\n-1.5\n-1\n-0.5\no\n0.5\n1\n-\nFigure 31c: Decadal temperature trend estimate derived from LLL\nradiative transfer model. The circles represent\nestimates with CO2 changing through the period and\nthe horizontal lines represent 95% confidence\nlimits. The x's represent the calculation with CO2\nfixed at the 1970 value. (Units are degree per\ndecade.)\n49","In addition to trends computed from profiles, a combined\nNimbus 7 SBUV, NOAA-9 SBUV/2, and NOAA-11 SBUV/2 total ozone\ndataset was compiled and adjusted to Dobson data. Integrated\ndata from 60N to 60S were used to compute an overall trend using\nthe autoregressive time series model for the period November\n1978-August 1990. The computed decadal trend was a decrease in\nozone of 3.25% (+ 0.27%) at the 95% confidence level. This\ncompares well with trends computed from TOMS and Dobson data.\n3.2.2 Temperature Trends (Gelman)\nLower stratospheric temperature conditions are being\nmonitored closely using CAC's daily global analyses, especially\nafter the eruptions of Mount Pinatubo, Philippines (June 1991)\nThe magnitude of the eruptions suggests that significant strato-\nspheric temperature increases may be anticipated. Figure 32\nshows the progression of zonally-averaged 30 mb (24 km) tempera-\nture for 1991 relative to the long-term (1978-91) average at\n10S. From January to June 1991, the tropical 30 mb temperatures\nwere approximately 2C below the long-term average. After the\nMt. Pinatubo eruption, temperatures have increased dramatically,\nreaching approximately 2C above average by the end of September.\nA presentation on the detection of stratospheric change\nwas made before the TOVS Pathfinder Science Working Group. The\nemphasis was on the important use of TOVS data in monitoring the\nstratosphere and the need for careful intercalibration of\nmeasurements from the successive satellite instruments. The\nWorking Group completed a Report that recommended an approach to\nreprocessing TOVS data for detecting climate change.\nA comparison was made between CAC analyzed stratospheric\ntemperature and geopotential height fields with radiosonde,\nrocketsonde, and lidar data. Preliminary results showed some\nproblems with lidar data during several summer seasons. These\ncomparisons are especially important because of the drastic\nreduction of the rocketsonde program. Ground-based temperature\ninformation are essential for interpreting long-term changes of\nCAC's upper stratospheric temperatures, which are based on\nsatellite data from successive operational TOVS instruments.\n3.2.3 Stratospheric Climatology (Nagatani)\nGlobal monthly mean rawinsonde data and CAC stratospheric\ngridded analyzed data are being used to compile a climatological\ndataset for NASA's High Speed Research Program. The purpose is\nto use the same initial input into various models (employed by\nresearchers around the world) for evaluating the impact of\nthousands of high-speed aircraft that are expected to be flying\nin the stratosphere in the 21st century. This dataset will be\nmade available at a central computer facility (NASA/Langley\nResearch Center) from which an international group of modellers\nwill be able to access data for initial input into their models.\n50","30 MB 1991 ZONAL MEAN TEMPERATURE\nAND LONG-TERM AVERAGE\n10S\n-50\n-51\n-52\n1991\n-53\n-54\n-55\n-56\nLong-term average\n-57\n-58\n-59\n-60\nJAN\nAPR\nJUL\nOCT\nFigure 32: Daily zonal average 30 mb (24 km) temperatures for\n1991 (solid line) at 10S, relative to the 1978-1991\naverage (dashed line). .\n51","Operational Products\n3.3\n3.3.1 Circulation/Temperature Analysis (Gelman, Nagatani)\nDuring the Northern Hemisphere 1990-91 winter, a strato-\nspheric warming took place (mid-January to mid-February), which\nwas accompanied by strong anticyclonic easterlies over northern\nlatitudes. Although the circulation never met the criterion for\na major stratospheric warming (10-mb westerly circulation was\nnot completely replaced by easterlies poleward of 60N) , the\ncirculation was quite active. Stratospheric temperatures were\nbelow their long-term average from mid-February to March 31.\nThe CAC is disseminating daily Southern Hemisphere 70 and\n30 mb charts to researchers in Antarctica, where lower strato-\nspheric temperature conditions are of special interest in regard\nto the \"ozone hole.' Figure 33 shows that 50 mb zonal temper-\natures, during 1991 at 80S, are near their long-term average.\nThis is consistent with reported near record low ozone values.\nCAC's stratospheric analyses are also being used in\nsupport of other scientific projects. One use is for data\nprocessing algorithms of several instruments on board the Upper\nAtmosphere Research Satellite (launched in September 1991)\n.\nAnother use is for the upcoming NASA/Arctic Airborne\nStratospheric Experiment (October 1991 - February 1992) to\nsupport aircraft routing and data interpretation.\n3.3.2 Atmospheric Angular Momentum (Kann, Long)\nThe major activity this year was the program review that\nwas conducted as part of the Chapman Conference on Geodetic Very\nLong Baseline Investigation: Monitoring Global Change in April\n1991. As a result of this review, it was recommended that the\ntwo-year commitment by the NMC/CAC to support the International\nSub-Bureau for Angular Momentum be continued. Further activities\nincluded coordination with the European Center for Medium -\nRange Weather Forecasts and the Japan Meteorological Agency.\nOne purpose is to have these two important Groups expand their\nefforts within this program. The responses of the agencies has\nbeen positive and the CAC is working closely with them to ensure\nthat all information is inserted into the Sub-Bureau data base.\n3.3.3 Ozone Analysis (Nagatani)\nAlthough the algorithm for all SBUV and SBUV/2 retrievals\nis undergoing change and the entire dataset will be reprocessed,\nday to day changes in the ozone values can still be monitored.\nFor example, ozone profile and total ozone values have measured\nthe effects of the Mt. Pinatubo eruption and the Antarctic ozone\nhole. Ground-based Dobson and Umkehr measurements are also\nundergoing reprocessing. Comparisons will then be made with\nreprocessed satellite and ground-based data.\n52","50 MB 1991 ZONAL MEAN TEMPERATURE\nAND LONG-TERM AVERAGE\n80S\n15\n-25\nU\n-35\nLong-term average\n-45\n-55\n-65\n-75\n1991\n-85\n-95\n105\nJAN\nAPR\nJUL\nOCT\nFigure 33: Daily zonal average 50 mb (20 km) temperatures for\n1991 (solid line) at 80S, relative to the 1978-1991\naverage (dashed line). .\n53","THIS PAGE INTENTIONALLY LEFT BLANK\n54","4. APPLIED CLIMATOLOGY\n4.1\nSurface Data\n4.1.1 Surface Climate Assessment (Miskus)\nMuch of the Northern Hemisphere recorded widespread and\nprolonged above normal temperatures during late 1990 and most of\n1991. However, there were also significant periods of subnormal\ntemperatures covering portions of the hemisphere. Bitterly cold\nArctic air enveloped eastern Alaska and western Canada during\nNovember; the western U.S. experienced its coldest December on\nrecord; frigid conditions persisted across eastern Canada during\nJanuary; most of Europe endured a cold February; and the\nwestern U.S. and Europe had unusually cool weather during late\nspring and early summer. Similarly, precipitation anomalies\nvaried greatly during October 1990-September 1991, as depicted\nin figure 34.\nIn the contiguous United States, conditions varied\ngreatly. While heavy winter rains inundated the Gulf Coast,\nlong-term drought continued across most of the far West, partic-\nularly in southern California, as the area recorded its fifth\nconsecutive below normal rainy season. However, at the end of\nFebruary and continuing into March, a series of strong Pacific\nstorm systems produced copious precipitation over much of\nCalifornia. Heavy spring rains soaked the Mississippi Valley,\nbut abnormal late spring and summer warmth and dryness afflicted\nthe Ohio Valley and mid-Atlantic. Although the 1991 Atlantic\nhurricane season was rather tranquil, Hurricane Bob slammed into\nNew England (in August), producing wind gusts of 115 mph, 7\ninches of rain, and causing an estimated $1.5 billion damage.\nIn Europe, a stormy and wet November and December, was\nfollowed by extremely dry weather during the first five months\nof 1991. Then, in late July and early August, torrential rains\nfell on central and southeastern Europe, especially Moldavia,\nthe western Ukraine, northeastern Rumania, and Austria, with the\nlatter reporting its worst flooding in 30 years.\nIn Asia, many areas had ample precipitation during late\n1990 and most of 1991. Parts of China, Korea, Japan, Siberia,\nthe Philippines, and South-east Asia endured several episodes of\ntorrential rains that caused extensive destruction and loss of\nlife. In July, some of the worst flooding on record battered\neastern China's Yangtze River Valley; while in August, copious\nrainfall caused Burma's worst flooding in 50 years south of\nRangoon. Also, intense August monsoonal rains produced\ndevastating floods in southwestern Cambodia. An extremely\nactive western Pacific Ocean produced 24 tropical storms, most\nof which became typhoons. In contrast, below normal rainfall\nin southeastern China, Taiwan, and the Philippines adversely\naffected hydrological and agricultural interests.\n55","12-MONTH GLOBAL PRECIPITATION ANOMALIES\nOCTOBER 1990 - SEPTEMBER 1991\n30W5\n0\n30E\nGOE\n90E\n120E\n150E\n150W\n201\n60W\n'90W\n0\n60N\n30N\n30N\nCOUNTRIES WITH INSUFFICIEN\nDATA FOR ANALYSIS\n30S\n30S\nLEGEND\nSHADING DEPICTS REGIONS WHERE\nPRECIPITATION ANOMALIES WERE ESTIMATED\nDRY\nTO BE WITHIN THE WETTEST 10% OR\nDRIEST 10% OF CLINATOLOGICAL OCCURRENCES\nWET\nCL MATE ANALYSIS CENTER\nOCT 1990 THRU SEP 1991\nNOAA/NWS/NMC\n60S\n60S\n0\n30E\n60E\n90E\n120E\n150E\n150W\n120W\n90W\n60W\n30W\nSignificant global precipitation anomalies for\nFigure 34:\nOctober 1990 - September 1991. Shading depicts\nregions where anomalies were estimated to be within\nthe wettest (double hatched) or driest (dotted) 10%\nof 1951-1980 climatological occurrences.\n56","Just before the Indian monsoon season began, an intense\ntropical cyclone (with estimated winds of 160 mph and 20-foot\nwaves at landfall) devastated coastal Bangladesh and its low-\nlying offshore islands. This storm left over 10 million\nhomeless and took more than 139,000 lives. The remainder of the\n1991 monsoon season (June-September) was fairly typical, with\nample rains occurring over southern and eastern India. Although\nPakistan and central and western India experienced generally dry\nconditions, timely rains kept crop production high.\nThe African Sahel experienced above normal rainfall in\nApril and May and near normal rainfall during the summer. In\nSenegal, early summer dryness was eased by late season rains.\nFarther east, however, rainfall was infrequent in northern Sudan\nand Ethiopia and this prompted concerns of additional famine.\nIn the Southern Hemisphere, widespread inundating rains\ndrenched northern Australia in early 1991, after an extremely\ndry November and December. The wet spell began with rains from\nCyclone Joy in late December and continued into early March. In\ncontrast, drought has afflicted much of Indonesia since mid-\nyear. In east-central South America, surplus spring rainfall\nwas offset by subnormal summer precipitation. After an\nextremely slow start to the rainy season in southern Africa,\ngenerous rains fell during late December to early March 1991.\n4.1.2 CLICOM (Katz)\nSoftware support for CLICOM's international program\ncontinues to be funded jointly by the NWS/Office of Meteorology\nand CAC. Work has concentrated on corrections and revisions to\ngraphic applications, based upon test results from WMO regional\nCLICOM experts. Additional efforts have focused on verification\nof non-graphic printer codes, user manual updates, installation\nprocedures, and instructions for the upcoming CLICOM version\n3.0. The release date of CLICOM 3.0 is scheduled for late 1991.\n4.1.3 SOLRAD (Yang)\nThe Solar Radiation Monitoring Network (SOLRAD) has\nperformed at about the same level as the previous year, even\nwithout funding. Five stations showed significant improvement\nin the data reporting rate, while six stations showed signs of\ndegrading. Due to the phasing in of ASOS, Dodge City, KS has\nhad to cease operation. The data communication system stayed\nthe same, with twenty-two stations reporting via AFOS and the\nrest submitting diskettes. In other related activities, data\ndistribution from CAC's Climate Dial-Up System has been normal\nand processed data (submitted to World Radiation Data Center\nLeningrad, USSR) are being quality controlled more stringently.\n57","Agricultural Applications\n4.2\n4.2.1 Climate/Agricultural Assessments (LeComte)\nClimatic fluctuations during the past year resulted in\ncrop losses for many important agricultural areas. A wet spring\nfollowed by a dry, hot summer reduced wheat, corn, and soybean\nyields in the United States. Summer drought in the Soviet\nNewlands hurt the wheat crop, while devastating floods during\nMay through July reduced rice production in China's Yangtze\nRiver Basin. Severe dryness occurred over sections of Indonesia\nand Australia during July-September 1991, drastically reducing\ncrop output. In addition, the southwest monsoon was weak over\nnorthern India which affected crop output.\nA WMO-sponsored visit was made (by D. LeComte) to Drought\nMonitoring Centers in Zimbabwe and Kenya (May 13-22, 1991). The\nmain purpose was to discuss the development of improved drought-\nmonitoring products. Various Climate Analysis Center maps and\npublications were distributed as examples of useful products.\n4.2.2 Africa FEWS (LeComte)\nCAC's Agricultural Weather Section began providing\nautomated color rainfall maps (developed by A. Herman,\nEllsworth) to the Agency for International Development. The\nmaps, in support of the Famine Early Warning System (FEWS)\nincorporate Meteosat rainfall estimates with reported ground\nobservations. Also, Inter-Tropical Convergence Zone location\ndata and written weather summaries were provided to FEWS.\nIn the Sahel region, the 1991 growing season was\ngenerally favorable and better than in 1990. Rainfall totals\nwere mostly near long-term averages, except for below normal\nvalues in Senegal, Mauritania, and western Mali.\nClimate Impacts: Monitoring\n4.3\n4.3.1 Products for Impact Evaluation (Laver)\nCAC products were incorporated into several color graphic\npackages on special topics. These included a ten-page package\non California Drought Conditions (see figure 35), and a seven-\npage package on Nevada Drought Impacts for the honorable Senator\nReed of Nevada (presented by the Director/NMC). Also, a special\n\"Executive Climate Summary\" was developed to depict current and\nhistorical climate information for top-level NOAA executives.\nThis four-page package (figure 36) contains geography, recent\nconditions, climatology, and a long-range (one-month) outlook\nfor requested areas of the world.\n58","WEST COAST DROUGHT UPDATE\nMarch 20, 1991\n0 Drought -\n5th Consecutive Year\nWet Season: Oct - Apr\nMoisture deficit reduced to\nWA\nmoderate-severe in\nCentral Valley and\nSan Joaquin Valley\nAs of Mar 18, 1991, total\nR\nrainfall was 65% of\nnormal in California\nthis season\no Reservoir storage\nestimate:\nCalifornia - 70%\no Snowpack in CA Sierra\nNevada Mountains increased\nfrom 16% on Mar 1 to 65% of\nnormal on Mar 18\nMODERATE\nDROUGHT\n0 Streamflow on Mar 1\nforecast at 15 - 25% of\nCENTRAL\nnormal, increased to\nVALLEY\n45 - 60% on Mar 18, 1991\n0 Widespread precipitation\n(1 - 3 inches)\nsince Mar 13\nDROUGHT SEVERITY\nNV\nPALMER DROUGHT INDEX\nSAN\nJOAQU\nmeasures prolonged moisture\ndeficit relative to normal\nMODERATE -2 to -3\nCA\nSEVERE -3 to -4\nEXTREME below -4\nIMPERIAL\nMOIST above +2\nData as of March 18, 1991\n(Based on preliminary data)\nFigure 35:\nSummary page of the ten-page (normally in color)\nCalifornia Drought Conditions briefing package\nprepared for the USDA/JAWF.\n59","NOVEMBER TEMPERATURE CLIMATOLOGY\nNORMAL NUMBER OF DAYS PER NOVEMBER\n10\n2.8\n5\n1-2\n0\n-0.6\n-5\no\n-6.6\nC\n13\n10\n-9.7\n-15\n-12.7\n-20\nFog\n-20.7\nPrecipitation (all frozen)\n-25\n2\n-30\n-28.3\n7-8\n-35\nRecord\nNormal\nNormal\nNORMAL\nNormal\nNormal\nRecord\nMONTHLY\nLow\nHigh\nMONTHLY\nDaily\nDaily\nExtreme\nExtreme\nHigh\nLow\nMinimum\nMaximum\nHighs Above 25F (-4C)\nHighs Below 10F (-12C)\nNOVEMBER PRECIPITATION\n3-4\n550\n7-8\n533\n500\n450\n400\n350\nLows Above 15F (-9C)\nLows Below OF (-18C)\n300\nmm\n2\n250\n203\n4\n200\n127\n150\n100\n42.4\n28\n50\n10.2\nT\n0\nDriest Nov. SNOWIEST Nov. Nml SNOW\nDaily Rec'd Daily Rec'd SNOW\nWettest Nov.\nNORMAL\n3 PM RH 80%\n3 PM RH 40%\nPrecipitation\nSNOWFALL\nMISCELLANY (NOVEMBER)\nSKY COVERAGE\n(Percentage of Hourly Reports)\nThunder is observed 1 day in 6000\nTemperatures have never reached 0°C during Oct 31-Nov 11\n12.2\nThe prevailing wind is from the East at 12 knots\n27.6\nThe normal monthly wind chill is -21°C\nA peak gust of 77 knots was reported in 1976\nThe normal November peak gust (each year) is 48 knots\n26.0\nWIND SPEED FREQUENCY DISTRIBUTION\nCalm (11.5%)\n34.1\n1 - 6 knots (22.0%)\n% of all reports with the given sky cover\n7 16 knots (53.1%)\nScattered (<50% coverage)\nClear\n17 27 knots (12.7%)\n28 40 knots (0.8%)\nBroken (>50% coverage)\nOvercast\n% of hourly reports with given wind speed\nFigure 36: Page from the Executive Climate Summary (ECS) color\npackage for November at McMurdo, Antarctica. This\nproduct was developed to depict current and historic\nclimate information for top-level NOAA executives.\n60","In addition, diskettes containing files of snow cover and\nsnow water equivalent (produced by the NWS's National Hydrologic\nRemote Sensing Center, Minneapolis, MN) were converted into\nimages and then color hardcopied. An experimental color version\nusing a special analysis scheme on these files is depicted in\nfigure 37. Also, test versions of \"detailed\" monthly Regional\nClimate Centers weather and climate impact reports have been\nproduced for downloading on the CAC's Climate Dial-Up System. A\n\"condensed\" test version from the Northeast RCC (NERCC) has been\nevaluated by the NWS/Eastern Region and their suggestions are\nbeing incorporated by the NERCC for potential AFOS transmission.\n4.3.2 Socioeconomic Impacts (Lehman)\nA number of interactive PC software products were\ndeveloped to model climate data sets used to assess departures\nfrom normal and the likelihood and impacts of extreme events.\nThese products were distributed to Regional Climate Centers,\ngovernment agencies and private groups. One software product\naccepts data file or keyboard input of monthly averages and\ncreates an output file of daily normals, with on-screen verifi-\ncation that the output is summed and/or averaged accurately.\nAnother product accepts data file input, calculates the maximum\nlikelihood estimates of the alpha and beta parameters in the\ngamma function model of the data, and gives the modeled proba-\nbilities of a range of outcomes including extremes. Other\nsoftware accepts keyboard input of the skewness parameter\nspecifying a gamma model and calculates the probabilities for a\nrange of standardized outcomes for the model.\n4.3.3 Regional Climate Centers (Bermowitz)\nA NOAA Project Office for regional climate applications,\nbased on the program of six Regional Climate Centers (figure\n38) was established at the NMC/Climate Analysis Center in\nNovember 1990. At that time, responsibility for the management\nof the Regional Climate Center's (RCC) Program was transferred\nto the Climate Analysis Center from the NOAA National Climate\nProgram Office. There have been a number of activities since\nthe transfer took place. A RCC Management Plan was developed\nwhich recognizes the importance of consensus decisions, funding\nof the centers, development of regional services and research\nprograms, peer review of operational services and applied\nresearch at the regional and national levels, and the flexible\napplication of these principles to the needs of each Center. A\nstrategy document, detailing desirable activities of a RCC as a\nkey link in a national climate services system, was also written\nand approved by each RCC. This document will provide a basis\nfor consistency and a means for judging performance.\nDuring the year, proposals from each RCC for operations,\nservices, and applied research were submitted to the Climate\nAnalysis Center for funding. Support was also provided to a\n61","Snow Water Equivalent\n4 to 6 6 to 8 8 to 10 10 to 12 12 to 14 14 to 16\nclouds\n2 to 4\n>16\nAn experimental enhanced analysis of snow water\nFigure 37:\nequivalent in the western U.S. (normally in color) .\nThe data and image were originally collected,\nproduced, and distributed by the NWS National\nOperational Hydrologic Remote Sensing Center in\nMinneapolis, MN.\n62","REGIONAL CLIMATE CENTERS\nNORTHEAST RCC\nCornell\nUniversity\nMIDWEST\nWESTERN RCC\nHIGH PLAINS RCC\nultnois State\nDesert Research\nWater Survey\nUniversity of\nInstitute\nNebraska\nSOUTHEAST RCC\nS.Car. Water Resources\nCommission\n*\nSOUTHERN RCC\nLouisiana State\nUniversity\nand\n38: Locations of the six Regional Climate Centers.\nFigure\n63","U.S. /Canadian climate change impacts effort for the Great Lakes\n(involving four of the RCC's) and a Southern Weather Data\nManagement Workshop (involving the other two RCC's).\nIn\naddition, a RCC Budget Initiative for FY 1993 was written to\nenhance the development of the RCC's as an important element of\na NOAA Climate Services Program. This initiative also proposed\nan additional level of activities consisting of database\ndevelopment, improvements to the NOAA SOLRAD Network, impact\nassessments of climate anomalies and potential climate change,\nand the transfer of current global change research results into\noperational climate services.\n4.4\nOperational Products\n4.4.1 Climate Dial-Up Service (Fulwood)\nThe first full year of Microvax operations of CAC's\nClimate Dial-Up Service (CDUS) went well; although, as with any\nnew system, modifications were needed. One feature requiring\nsubstantial effort was modem operation refinement to disconnect\nany modem from the CDUS if no signal was detected during a\nspecified time period. Also, many of the CDUS automated data\nretrieval routines and their NAS9000 counterparts were modified\nto operate properly under this new environment. In addition,\nCDUS software was modified and a new forecast release time was\nestablished to accomodate security requirements and update\nprocedures for CAC/Prediction Branch's 6-10 day forecasts.\nInterest in the CDUS continues to increase with many\nrequests for new accounts and renewals of existing accounts for\nthe NWS/Family of Services. The total number of monthly users\nis about 400. The network capabilities of the CDUS are being\nutilized by routine transmission of CLIMAT data to NCDC elimina-\nting the need for computer tapes. In addition, accounts were\nestablished for the Regional Climate Centers that have enhanced\ninformation exchanges between the Centers and CAC.\n4.4.2 Daily Weather Maps (Dionne)\nA number of activities were conducted to enhance the\nproduction of the Daily Weather Maps. A new contract/printer\nwas selected, which has resulted in greater attention to the\nproper registration of base maps and overlays. Most of the\nartwork is now produced on an interactive workstation (by NMC/\nMeteorological Operations Division), which eliminates the need\nfor manual shading of the maps. This action has also improved\nthe quality of the final product and reduced the time needed in\ndata preparation. Finally, the processing of subscriptions, and\nfree-list maintenance continues in a timely fashion.\n64","4.4.3 Weekly Climate Bulletin (Heddinghaus)\nThe production of the Weekly Climate Bulletin (WCB)\ncontinued to improve, with the number of recipients now up to\n1500. All maps are now automatically analyzed which enables\nquicker and easier publication, utilizes fewer people, and main-\ntains quality standards. Also, most of the pages are routinely\nproduced on an workstation (using desk-top publishing software).\nA Global Climate Highlight page was added as a regular\nfeature (see figure 39), replacing the weekly degree-day maps.\nThe WCB also featured articles on climate-related impacts that\nwere received from Regional Climate Centers (RCCs) These\nincluded: drought in California and subsequent beneficial March\nrains, heavy rain and flooding in the lower Mississippi Valley,\nand low soil moisture conditions in the Corn Belt, Northeast,\nand mid-Atlantic states.\nOther special articles included: typhoons in the Far\nEast, Tropical Cyclone (2B) which devastated Bangladesh, and\nHurricane Bob which struck New England. In addition, monthly\nand seasonal historical data from the National Climate Data\nCenter and eight El Niño Southern Oscillation (ENSO) advisories\nfrom CAC's Diagnostics Branch were included during the year.\n4.4.4 Weekly Weather and Crop Bulletin (LeComte)\nThe production of the Weekly Weather and Crop Bulletin\ncontinued, as well as changes to enhance its appearance. More\npages are now being produced on a PC, using desktop publishing\nsoftware. The international temperature and precipitation\ntables and U.S heating degree day tables were converted to this\nmethod which decreases the need to photographically reduce pages\nand will be economical in the long run.\nSpecial articles were published in the Bulletin including\none on the devastating cyclone which struck Bangladesh (April\n1991) A historical list of storms (included in the article)\nindicated that this storm was one of the deadliest of all time.\nOther articles dealt with the heavy March rains in California,\nthe December freeze in the western U. S., the record rainfall in\nthe lower Mississippi Valley, and the South African drought.\n4.4.5 Weekly Climate and Weather Update (Sabol)\nA number of changes have been made to the Weekly Climate\nand Weather Update. The orientation of the page was changed and\nthe size of text type reduced (figure 40), which allowed more\nspace for maps and/or graphics. Then, values were added to the\nmaps to give the reader an indication of the highest\nprecipitation total or the strongest temperature anomaly. A\nlead story was added and highlighted in color and the maps were\nconverted to a full-color, fully-automated analysis.\n65","GLOBAL CLIMATE HIGHLIGHTS FEATURE\nBOE\n100\n100\nTOTAL PRECIPITATION\n50\n50\nJULY 21 - AUGUST 3, 1991 (14 days):\nI\nAt least 12 daily reports were necessary\n50\n190\nfor inclusion\n32\n50\n48\n100\n147\n100\n127\n101\n132\nINDIA\nPAK\n332\nBANGL\nSI\nGuna\n300\n100\nAHMEDABAD\n98\n163\n208\nPendra\n300\n283\nCalcutta\n352\nBhopal\n293/\n138\n298\n12\n130\n200\n177\n132\n202\n98\n241\n182\nBhubaneshwar\n48\n200\n100\n336\n20N\n20N\n300\n34\nBombay\n300\nBAY\nARABIAN\n286\n101\n200\nOF\n24\n100\nSEA\n200\n50\n50\n89\nBENGAL\n80E\nAfter a slow start to the 1991 monsoon across central and western India, torrential downpours have inundated\nmuch of central India from the northwestern Bay of Bengal coast westward into Eastern Gujarat during the\nlast two weeks. According to press reports, more than 10,000 individuals were left homeless and several\nhundred people lost their lives as a number of rivers, including the Wardha River in Maharashtra's Nagpur\nregion, swept out of their banks and engulfed numerous villages.\n500\nCUMULATIVE PRECIPITATION\n450\nOBSERVED (solid line) vs. NORMAL (dashed line)\n400\nAHMEDABAD, GUJARAT, INDIA\n350\nJUNE 1 - AUGUST 3, 1991\n300\n250\n200\n150\n100\n50\n0\nJUNE 1\nJUNE 15\nJULY 1\nJULY 15\nAUG 1\nFigure\nGlobal Climate Highlight Feature page from the Aug.\n39:\n3, 1991 issue of the Weekly Climate Bulletin,\ndepicting the heavy late July monsoonal rains across\nwest-central India.\n66","3.81 INCHES OF RAIN\n3.89 INCHES OF RAIN\n9°F BELOW NORMAL\n3°F to +6F\n3°F to 3°F\nCape Hatteras, NC\nParkersburg, WV\nAbove 6F\n-6°F to -3°F\nAbove 4\n0.1\" 1\nBelow 6F\nBoston, MA\n3.83 INCHES OF HAIN\n2\" 4\n1 2\nBelow\nBirmingham, AL\nDEPARTURE OF AVERAGE TEMPERATURE FROM NORMAL (°F)\n13°F BELOW NORMAL\n1200 GMT SUNDAY - 1200 GMT SUNDAY\nLansing, MI\nCLIMATE ANALYSIS CENTER, NOAA\nCLIMATE ANALYSIS CENTER, NOAA\nCOMPUTER GENERATED ISOPLETHS\nCOMPUTER GENERATED ISOPLETHS\nBASED ON PRELIMINARY DATA\nOBSERVED PRECIPITATION (INCHES)\nBASED ON PRELIMINARY DATA\n10°F BELOW NORMAL\n3.34 INCHES OF RAIN\n9°F BELOW NORMAL\nBlytheville AFB, AR\nWausau, WI\nMonroe, LA\nSeptember 22 - 28, 1991\nSeptember 22 - 28, 1991\nFigure 40: The new format of the cover page of the Weekly\n2.98 INCHES OF RAIN\nPalacios, TX\n6°F ABOVE NORMAL\n4.06\nCut Bank, MT\nTO\n0\n8°F ABOVE NORMAL\n0.19\nPhoenix, AZ\n0\n0.04\n.0\n-1\n11°F ABOVE NORMAL\nSan Bernadino, CA\n+2\n3.96\n9°F ABOVE NORMAL\nMedford, OR\n0.02\n4.58\nD\n+6\n+1\n0.84\n+4\n0.06\n0\n0.68\nClimate and Weather Update.\nHEAVY RAINS DRENCH DEEP SOUTH, ATLANTIC COAST: Severe thunderstorms\nbrought torrential downpours, high winds, and hail to the deep South as cold air plunged\nthrough the nation's midsection. Almost six inches of rain deluged portions of Texas\nwhile totals exceeded three inches across large sections of the South (top right). The\nleading edge of the same cold air mass also brought heavy rains and severe\nthunderstorms to New England and the Atlantic coast. Winds gusted to 110 MPH at\nBoston's Logan International Airport, and up to four inches of rain inundated the\nRECENT WEEK (September 22-28,1991): - Rare thunderstorms rumbled across the San\nFrancisco Bay area while unusually wet weather persisted across central and southern\nCalifornia. The western states experienced unseasonably warm weather as temperatures\naveraged up to 11°F above normal (bottom right). In sharp contrast, subnormal\ntemperatures dominated the central and eastern states. Departures reached -13°F in\nMichigan as temperatures dipped to record lows by the end of the week. Hawaii reported\nnear normal temperatures while Alaska was unseasonably warm, with temperatures as\nCURRENT SITUATION (September 29 - 30, 1991): Summer-like conditions returned to\nportions of the central and southern United States, with highs exceeding 90°F in the\ncentral Plains. Strong thunderstorms dumped almost eight inches of rain near\nJacksonville, FL and brought showers to much of the south Atlantic and central Gulf\ncoasts. In sharp contrast, wintry weather affected the upper Great Lakes and New\nEngland. Snow and sleet fell in parts of Vermont and northern Maine while record cold\nHYDROLOGIC CONDITIONS: Major flooding developed along the Rio Grande River in\nsouthwestern Texas. Water was released from several reservoirs as they reached record\nlevels. Significant damage occurred at Big Bend National Park, and many roads and\nbridges in the arca were washed out. Levees broke about sixteen miles southcast of\nPresidio, flooding large tracts of farm land and closing roads. Some minor to moderate\nriver flooding was also reported during the week in parts of south-central Texas while\nbeneficial rains helped ease abnormally dry conditions in parts of the middle Atlantic\nOUTLOOK (October 1 - 5, 1991): Above normal temperatures will persist across the\nwestern quarter of the nation and are expected to develop in the Northeast by the end\nof the week. A surge of tropical moisture may bring soaking rains from the Carolinas\nnorthward by midweek. Chilly Canadian air is expected to push southward through the\nPlains by the weekend, generating shower activity over the castern quarter of the nation.\nLONG RANGE OUTLOOKS: October Monthly Outlook and October through December Outlook for the United States are attached.\nCLIMATE AND WEATHER UPDATE\nHydrometeorological Information Center, OH, NWS\nContacts: P. Sabol, J. Harrison: 301-763-8071\nClimate Analysis Center, NMC, NWS\nMonday, September 30, 1991\ngripped Michigan as temperatures dipped into the twenties.\nS. Kroczynski; 301-427-7630\nmuch as 7°F above normal.\nAtlantic coast\nregion.\nOF","As a result of the above efforts, more information is now\nprovided, improvements in readability and attractiveness were\nmade, and the production time was reduced. Also, frequent use\nhas been made of monthly precipitation and/or temperature\nquantile analyses to give the reader some perspective on how an\nanomaly compares to climatology. In addition, full-color maps\nof one- and three-month temperature and precipitation outlooks\nwere published on a second page. This product is now included\nin the Secretary of Commerce's Weekly Briefing Book.\n4.4.6 PRESTO - National Capital Summary\n(Harrison)\nThe production of PRESTO continues with improvements and\nmodifications made, as required. For example, the January 1991\nissue featured a \"special decadal edition. The archival of\nmonthly temperature and precipitation data for National,\nBaltimore, and Dulles Airports has been installed into Lotus\nsoftware and has been beneficial for statistical computations.\nCurrently, the archival of daily data (January 1949 - present)\nfor National Airport is almost completed and interactive soft-\nware is being developed to manipulate the archived daily data.\nAlso, microvax software was developed to extract the daily local\ntemperature and precipitation data to automatically produce\nstatistics tables. In addition, PRESTO is now distributed to\nall Washington D.C. television stations, after a visit by local\nTV weathercasters. Lastly, the number of recipients is now 280.\nSupporting Projects\n4.5\n4.5.1 Graphics Applications (Miskus, Herman)\nA major milestone in the operational graphics production\nwas reached this year. The capability now exists to produce\noperational maps automatically at either the World Weather\nBuilding or USDA/JAWF, send them in various formats across the\nnetwork, and print publication-quality monochrome versions (see\nfigure 41) at both locations. The technique includes a modified\nNCAR graphics software package, a specialized set of analysis\nprograms and options, automated Cray and Apollo batch jobs, and\noptional workstation capabilities for data modification. Color\nscreen and hardcopy output was developed for the above maps, for\nthe Palmer Drought Index, and Northern Hemisphere ozone.\nAlso, Microvax software was developed that automatically\ncollects half-hourly METEOSAT satellite-derived cloud\ntemperatures over the African Sahel, converts them to 10-day\nrainfall estimates, compares them with ground-truth rainfall,\nand then color hardcopies the analysis. Improved mathematical\nmodels for the METEOSAT estimates have now reduced the mean\nsquare errors in semi-arid (dry) areas from 15mm to 8mm, and\nfrom 35mm to 20mm in tropical (wet) regions. In addition,\nsoftware development is underway that will plot and/or contour\ndata for any area with several types of geographic projections.\n68","EXTREME MAXIMUM TEMPERATURE (°F)\nSeptember 15-21, - 1991\n59\n55\n605g\n68\n61\n64\n70\n80\nin\n90\n9Q\n80\n70\n80\n100\n90\n90\nU\n80\n90\n°F\n90\nT\n70\n>90\n60\n100\n80\n90\n80\n90\n90\nCLIMATE ANALYSIS CENTER, NOAA\nComputer generated isotherms\n100\n20\nBased on preliminary data\nto\n54\nAbnormally warm weather affected a large portion of the East and Far West as highs exceeded 90°F (top). Oppressive heat\nand humidity produced apparent temperatures over 100°F in the deep South, mid-Atlantic, and parts of the Southwest\n(bottom).\nEXTREME APPARENT TEMPERATURE (°F)\nSeptember 15 - 21, 1991\n53v\n59\n55\n605g\n55\n60 %\n64\n70\n80\n70\nZD\nink\n80\nas\n80\n80\ngo\n85\n30\nsoil\n80\n90\n80\n100\n60\n95\n95/\n95\n85\n90\n90\n100\n80\n80\n85\n100\n95\ntoo\n80\n90\n100\nCLIMATE ANALYSIS CENTER. NOAA\n95\nComputer generated contours\n95\nBased on preliminary data\n95\n100\nGENERAL HEAT STRESS INDEX\"F\n95\n90\n95\n80-90 Caution\n90-105 Extreme Caution\n100\n38\n105-130 Danger\n32\n1\n>130 Extreme Denger\n3\nHATCHED AREAS>100°F\nFigure 41: Examples of the publication-quality U.S. analyses\nautomatically produced twice a week for use in CAC\npublications. Weekly data are analyzed by a pseudo-\noptimal interpolation analysis scheme (on the Cray\ncomputer) and sent to a workstation. Graphics soft-\nware then produce a monochrome or color version of\nseveral parameters.\n69","4.5.2 Systems and Communications (Thomas)\nHardware systems used by the CAC have been enhanced in a\nnumber of ways. Seven new PC systems (25 MHz-386) were added to\nenhance the office automation and publication capabilities. A\nnew Digital Equipment Corporation VAX 4000 series 300 system was\nadded to the VAX cluster to support the Data Host Facility of\nthe Network for Detection of Stratospheric Change. Also,\nEthernet was expanded to include most PC's operated by the CAC's\nAnalysis and Information Branch and the Director's Office.\nFigure 42 illustrates the extent of the current network for\nCAC's Analysis and Information Branch and the Director's staff.\nIn addition, a 6250 reel to reel tape drive has replaced\nan older one; a thinwire IEEE 802.3 Ethernet multiport repeater\nwas obtained; DEC Pathworks, a software product that allows\nnetworking of PC's was installed on the VAX cluster; and NCAR\ngraphics were installed on the VAX cluster to make it compatible\nwith the NCAR package that was installed on the Cray and Unix\nworkstations. The use of the VAX systems has greatly increased\ndue to the launch of the UARS satellite, the addition of the\nRegional Climate Centers, and the Arctic Airborne Stratospheric\nExperiment. Operations had an uptime exceeding 98% for the year.\n4.5.3 Satellite Monitoring Products (Tinker, LeComte)\nTen-day and monthly maps and gridfields, depicting\nestimated rainfall and percent of normal rainfall across the\nAfrican Sahel, were routinely generated on workstations, printed\non color devices, and provided to the AID-Famine Early Warning\nSystem. These color maps combined any available surface\nrainfall reports with 30-minute METEOSAT satellite data to\ncreate a \"first guess\" analysis. A monochrome version (normally\nin color) of 10-day rainfall estimates is depicted in figure 43.\nIn addition, the lower resolution colorized cloud-top\ncounts were generated on both a 10-day and monthly basis as an\naid to the rainfall analyses. These charts are created on the\nVDUC terminal and printed on a color device. Both the spatial\nand temporal resolution of the product were increased to improve\naccuracy and to create a product that samples the same data as\ncolor maps. Thus, the previous 4-km resolution METEOSAT images\nwere replaced with 2-km resolution images, and the frequency was\nincreased from once every 3 hours to once every 30 minutes.\n4.5.4 Climate Assessment Data Base (Miskus)\nIn maintaining an operational Climate Assessment Data\nBase (CADB), all problems were resolved without any major delay\nor data loss. One task involved the transfer of several CADB\ndata files from one disk pack to another on the NAS mainframe.\nThis required extensive and complex software development, since\nthe two types of disk packs were incompatible. Another problem\n70","LAN BRIDGE\nTO\nPC398\nWWB\n100\n(WWB ROOM 806\nNETWORK\nETHERNET\nNESDIS\nREPEATER\n140.90.129.0\nROUTER\n(MULTIPORT)\nNASA\nPHYLMM\nAIBROU\nVARS\n56.211\n140.90.129.141\nGSFC\n58.1007\n56 KBS DECNET\n(WWB ROOM 810)\nVAXSTATION\nPC386\nPC388\n3100/40\n140.90 129.238\n56.216\nVT320\n1X 380 MB\nMISKUS\nUSER TERM\nFISBOWL\nSBUV\nKAUI\nHAWAII\n1X 1000 MB\nVAX\nNESDIS\n140.90.129.117\n140.90.1 129.207\n140.90.129.124\n140.9 129 113\n4000/300\nVT340\n(WWB ROOM 600\n(WWB ROOM 800)\n(32 MB MEM)\nCONSOLE\n86.212\n58 188\nPC366\nPC388\n(WWB ROOM 810\n(WWB ROOM BOB)\n(WWB ROOM soa)\nPC486 BSA\nVT320\nGAIL\nTHEDO\nCOMMON\nVT320\n140.90 129.78\n140.90 129. 121\nVT320\nUSER TERM\nNZMS\nTHOMAS\nCOMMON\n(WWB ROOM 811)\n(wws ROOM 800\n140.80 129.106\nNESDIS\nPC386\n140.90 129.72\nPC3866X\nVT340\n56214\n189\nLONG\n(WWB ROOM 810)\n(WWB ROOM 606)\nVAXSTATION\nTERMINAL\nNAMS\n3100/40\nSERVER\nVT340\n140.90.129.102\nDIONNE\nRAIN\nWILD\nDECNET\n140.90.129.101\n56 180\nDIAL\n140.90 129.7\nMODEM\n(WWB ROOM BOO\nAIBAX\n(WWB ROOM 808)\n(WWB ROOM 811)\nVT320\nMVII\nMALI\nw 250\nSKY\nPC386\nPC386\n13\nCOLOR\n140.9 129. 11\nMByte\nPRINTER\n56 182\n(WWB ROOM 811\n(WWS ROOM 808)\n1X 400 MB\nFULWOOD\nRCC\n(SYSTEM)\nDIAL\nOZONE\nDIAL\nPC366\nMV 3400\n2X 150 MB\n140.90 129 122\n140.90 129 202\n(20 MEM)\n2X 650 MB\nDIAL\n(WWB ROOM 800\n(WWB ROOM 811)\nDIAL\nPC266\n(WWB ROOM 808)\nAIB SRU\nMEL\nTEKTRONIX\nTERMINAL\n4693FX\nVT320\nSERVER\n140.90 129.123\nUSER TERM\n56.2151\nMILLER\nAIBMET\n(WWB ROOM 811)\nDEC\n(WWB ROOM 808)\n140.9 1.129.202\nLG02\nVT340\nEPSON\n140.90.129.79\nHERMAN\n217\nPRINTER\nPRINT\n(WWB ROOM 805)\nCALCOMP\n(WWB ROOM 800\nSERVER\nDRAWING\nPRINT\nMASTER\nPC286\nPC366\nPC386\nPC306\nOAHU\n(WWB ROOM 806)\nCACBGL\n140.90.129 112\nBOL PRINTER\nLAVER\nLEHMAN\nAIBSUP\n(WWB ROOM BOS)\n140.90.129 107\n140.00 129.115\n140.90.129.209\n1002\n1004\n36 1001\n(WWB ROOM 805)\n(WWB ROOM 805)\n(WWB ROOM 811)\n(WWB ROOM 805)\nCAC's ethernet network for one of its Branches and\nFigure 42:\nthe Director's Office, located in the World Weather\nBuilding.\n71","ESTIMATED RAINFALL (mm)\nOCT 10, 1991 - OCT 20, 1991\n30\n10\n29\n46\n32\n5\n22\n83\n3\n20\n33\n12\n12\n81\n5 to 10 10 to 25 25 to 50 50 to 100 100 to 150 150 to 200\n>200\nOCEAN\n>LAND\n<5\nFigure 43: Analyzed decadal rainfall estimates of the African\nSahel (normally in color), with synoptic rainfall\ntotals plotted. The technique combines ten-day\nMETEOSAT satellite rainfall estimates with decadal\nground station rainfall totals, producing a \"first-\nguess\" analysis that can be manually adjusted to\nremove biases between the station and satellite\ndata.\n72","was the slow turn-around time of the NAS, which created errors\nin the sequential data and data files. This problem was not\nonly solved, but any future delays of this magnitude are now\nanticipated by the program. Also, special software was modified\nthat corrects underestimated precipitation totals caused by new\nor changed synoptic reporting practices.\nAn extensive update of the entire CADB station library\nand its associated software was completed, which resulted in\nacquiring dozens of new synoptic stations. Major modifications\ninvolved updating the station's quality flag, country and region\nnumbers, city and country names, and any incorrect latitudes,\nlongitudes, and elevations. In addition, modifications to the\nmonthly CLIMAT data collection and transmission programs have\nimproved data quality and increased data quantity. Newly\ngenerated statistics allow quick detection of problems, and new\nsoftware enables the manual input of missing CLIMAT into the\nCADB. Also, the electronic transmission of the daily/monthly\nCADB and monthly CLIMAT data (via Microvax computer) has\nrapidly increased the turn-around time of sending data from CAC\nto NESDIS/NCDC and eventually to their users.\n4.5.5 JAWF Briefings (LeComte)\nCAC meteorologists at the Joint Agricultural Weather\nFacility (JAWF) continued to keep USDA meteorologists and crop\nanalysts informed of world weather events by means of daily and\nweekly briefings. Highlights of the weekly briefings included\nthe drought in the Soviet Newlands, floods in China, the cyclone\nin Bangladesh, and the drought in eastern Australia. USDA crop\nanalysts were kept up to date on the progress of the El Niño/\nSouthern Oscillation event and its potential impact on crops.\n73","THIS PAGE INTENTIONALLY LEFT BLANK\n74","5. CLIMATE PREDICTION\n5.1\nEmpirical Studies\n5.1.1 Medium-Range (6-10 day) Forecast Development (Epstein)\nEfforts have focused on reprogramming the imperfect prog\ntemperature forecast system to ensure its predictability\nfactors, predictand selection procedures and regression\ncoefficients. Numerical 5-day mean temperature predictions,\nbased on the original set of predictability factors, are\navailable to 6-10 day forecasters and apparently have reasonable\nskill although this has not been quantified.\nA study was also made of the influence of ENSO condi-\ntions, in a climatological sense, on 5-day precipitation\nfrequencies and amounts conditioned on the frequencies. The\nresults confirmed the strong influence of ENSO on precipitation\nand identified regions in which the effect was primarily one of\nfrequency, primarily one of amount with little influence on\nfrequency, or due to a combination of frequency and conditional\namount. The ENSO effects, while not necessarily large every-\nwhere, did prove to be more widespread than previously thought.\n5.1.2 Seasonal Empirical Prediction (Livezey, Barnston)\nExperiments to compare the analog prediction technologies\nof the CAC and the USSR Hydrometeorological Center culminated in\nthe completion of several experiments in early 1991. This was\nachieved during the visit of Professors G. V. Gruza and E. Ya.\nRankova, under a - Soviet Bilateral Agreement. of primary\ninterest to CAC was the viability of Gruza's \"optimization\"\nconcept for a priori selection of U.S. seasonal analog forecast\npredictors. Validation of this procedure would lead to a more\nefficient design of analog prediction models and the elimination\nof some subjectivity in the process that inevitably resulted in\nover statements in realizable skill. The procedure's effective-\nness was tested using CAC predictor and predictand data sets and\ncross-validation methods. Skills of different models were\nassessed on the basis of 40 seasonal forecasts at 100 stations.\nTests of the Soviet GRAN (\"Group Analog\") method were\nfirst run without optimization, using the a posteriori selected\npredictors employed in the CAC system. A version of the CAC\nsystem which excludes antianalogs (similar to GRAN without\noptimization) was run for comparison. The results shown in\ntable 2 reveal that these systems perform in a practically\nidentical manner when predictor and predicted data sets are the\nsame. GRAN forecasts were then made using all available predic-\ntors and then using only predictors selected by optimization.\nAlso, values in the last row of the table show that objective\na priori predictor selection by optimization is just as\neffective as subjective a posteriori selection.\n75","Winter\nSpring\nSummer\nFall\nCAC Model\n(no antianalogs, a posteriori\n0.11\n0.05\n0.09\n0.08\nselected predictors)\nGRAN Model\n(no optimization, a posteriori\n0.11\n0.04\n0.09\n0.05\nselected predictors)\nGRAN Model\n(no optimization, all\n0.04\n0.08\n0.06\n0.04\npredictors)\nGRAN Model\n(optimized predictors)\n0.11\n0.04\n0.13\n0.07\nTable 2: U.S. seasonal forecast skill, (Heidke) , 1950 - 1989.\n76","5.1.3 Soil Moisture and Temperature Forecasts (van den Dool,\nHuang)\nThe purpose of this project is to calculate daily soil\nmoisture for the United States and to improve long-range\ntemperature forecasts with the knowledge of antecedent soil\nmoisture. As a pioneer study, the relationship between monthly\nmean precipitation (MMP) and temperature (MMAT) was examined by\nusing MMP as a first order proxy for the soil moisture anomaly.\nThe study was based on both climate division and station data\nduring the 1931-87 period. Preliminary results showed that the\nP-T correlation is generally negative, with the maxima in summer\nand for the interior U.S. continent.\nResults also showed, on the whole, that the inclusion of\nMMP as a second predictor only slightly improved the MMAT\nforecasts. This is due to the fact that the first predictor\n(temperature persistence) has accounted for the MMP's predictive\nvariance. However, in wet months, the inclusion of MMP as a\nsecond predictor can make a better MMAT forecast than using\ntemperature persistence only (see figure 44). The higher skill\nin wet months suggests that for the monthly or longer range MMAT\nforecasts, the P-T and T-T correlations can be used with more\nconfidence in these months. Moreover, the predictability of the\nempirical forecasts can be determined when making the forecasts\naccording to the current MMP.\n5.1.4 Long - Range Forecasting of U.S. Surface Temperature at\nNon - Zero Lead Times (Barnston)\nAn exploratory study of long-range forecasting of U.S.\nsurface temperature, at non-zero lead time using canonical\ncorrelation analysis (CCA), has produced evidence of useful\nskill at certain times of the year - particularly late summer\nand late winter. This feature is shared to varying degrees by\nforecasts with leads of one-half month to three months and\naveraging periods of one to three months. The components of\nthe predictor fields for several periods preceding forecast\ntime that give rise to skill in the forecasts are identified as\na standard part of the CCA prediction procedure, making\npossible some understanding of the origin of the skill.\nFor example, figure 45a shows the regional distribution\nof cross-validated predictive skill for forecasts of mean\nAugust U.S. temperature made in mid-July (half month lead time).\nFigure 45b shows the main anomaly centers of the mid-June to\nmid-July sea surface temperature (SST) pattern associated with\nthe strongest of the several modes leading to the forecast skill\nreflected in figure 45a. In this case, anomalously warm SST in\nthe northern equatorial Atlantic Ocean in the latter half of\nJune through the first half of July tends to be followed by hot\nAugust weather in much of the eastern half of the U.S. The SST\npattern (figure 45b) has sometimes been noted in the summer\nfollowing the completion of a warm ENSO episode.\n77","120W\n100W\nBOW\n30 20\n2030\nSON\nSON\n30\n3073\n30\n40\n40\n30\nB\n40N\n3033\n40N\n30-4\n30\n30\n30N|-\n30N\n30\n40\n40\n30-\n120W\n100W\nBOW\n120W\n100M\n80N\n5\n40 20 20\n30 20\n,30-\n20.29\n20\n30KD\n40\nSON-\nSON\n50TH\nLizo\n30\n60\nO\n40\n60\nO\n40N\n40N\n8\n302\nO\n7\nO\nIf\nR\nC\n70\n40\nB\n>30\n30 30\n30N\n50\n30N\n120W\n100W\nBOW\nFigure 44 : Temporal correlation between observed August\ntemperature and predicted by regression models.\nIn the upper panel, the predictor is July\ntemperature. In the lower panel, the predictors\nJuly temperature and precipitation and the\nare\nverification shown is for wet initial Julys only.\nDevelopment of regression and verification are based\non 1931-1987, - i.e., , dependent data.\n78","a\n0\nb\n160W\n140W\n120M\nMOON\nBOW\n60W\nKOW\n20W\nDD\n20E\n40E\n60E\nBDE\n100E\n120E\n14DE\n160E\n180\n6DN\n60N\nis\n42\nG\n+\n50N\n50N\n40N\n,\n40N\n30N\n30N\n20N\n+\n20N\n10N\nON\nEQ\nEQ\n10S\n10S\n+\n20S\n20S\n30S\n30S\n40S\n40S\n160W\n140W\n120W\n100W\nSOW\n60W\n40W\n20W\n00\n20E\n40E\n60E\nBOE\n100E\n120E\n140E\n160E\n180\n45: Diagnosis of CCA forecasts of United States August\nFigure\nmean surface temperature made at mid-June - (one-half month lead\ntime) on the basis of near-global SST, Northern Hemisphere 700mb\nheight, and U.S. surface temperature itself during four previous\n1-month periods. Part (a) shows the spatial distribution of\nforecast skill cross validated over a 35-year period (expressed\nas a correlation between forecasts and observations), , where the\nlight stippling denotes a skill of 0.3 or higher and dense stip-\npling 0.5 or higher. Part (b) illustrates the portions of the\nSST field for the mid - June to mid-July predictor period that\ncontribute most strongly to the skill pattern shown in part (a).\nIn this example, positive SST anomalies in the north equatorial\n.\nPacific, near Indonesia, etc. and negative SST anomalies south of\nthe Aleutians tend to be followed by anomalously warm surface\ntemperatures in the eastern U.S. and the southern Rockies.\n79","5.2\nDynamical Methods\n5.2.1 DERF - Operational Feasibility Assessment (Ebisuzaki)\nThe purpose of this study is to use an ensemble of\nforecasts to produce a single forecast. One such effort is\nfocused on testing a modified lagged average forecast (LAF) -\nensemble which is theoretically better for finding spread-skill\nrelationships. The LAF ensemble being tested in the DERF proba-\nbility forecasts consists of 9 MRF forecasts run from analyses\nevery 6 hours over a 48-hour span. Here, the perturbations\nconsist of the forecast errors from earlier forecasts. A study\nis being conducted on an ensemble whose perturbations are still\ngenerated by forecast errors; however, the amplitudes of the\nperturbations are scaled by the age of the forecast. In\naddition, both positive and negative normalized forecast errors\nare used. Using a six hour spacing over the span of two days,\nthe ensemble consists of 17 members including the control run.\nResults show that this modified LAF produces better\nforecasts than the control forecast even at short forecast times\n(figure 46). This is an improvement over the simpler LAF which\ngenerally produces a worse forecast at shorter forecast times\n(figure 47), In addition, this modified LAF should show a\nstronger spread-skill relation because the spread is no longer\ndominated by the older members of the LAF ensemble which would\nskew the results. A stronger spread-skill relationship is\nnecessary for making predictions of the forecast skill useful.\nSo far, 5 modified LAF ensembles were run at T40 resolution.\nThe results have been encouraging enough that for the second\nphase, the T62 version of the MRF is being used and two\nensembles were completed. Some of the forecast dates will\ncoincide with either those from DERF Probability Tests and case\nstudy experiments or with those from external ensemble runs.\n5.2.2 DERF - Regime Dependent Predictability (Tracton)\nA detailed evaluation and diagnosis of forecasts for\nselected case studies are being used to assess the dependence of\nforecast skill upon circulation regime and, especially, regime\ntransitions. Each case involves generating a 9 member LAF\nensemble with a 6 hour spacing between initial conditions\n(T80 model) . To date, in this extremely computer-intensive\nexercise, 9 of 20 ensembles have been run. Extensive time and\neffort have been expended in generating appropriate charts,\ndiagnostic output, and verification quantities. Also, to assess\nalternative methodologies for generating ensembles, some cases\nhave been partially rerun with the modified LAF procedure\ndescribed in Section 5.2.1.\n80","ENS1, 1-10-90, - CONTROL VS MODIFIED LAF\n1.0\n0.9\n0.8\n0.7\n0.6\n0.5\n0.4\n0.3\n0.2\n0.1\n0.0\n0\n2\n4\n6\n8\n10\nDAYS\nFigure 46: The forecast skill of the control run (solid) and a\nmodified LAF (dash) for a typical ensemble. Both\nthe control run and the ensemble are T40.\n81","T80 2-5-89, CONTROL VS LAF\n1.0\n0.9\n0.8\n0.7\n0.6\n0.5\n0.4\n0.3\n0.2\n0.1\n0.0\n0\n2\n4\n6\n8\n10\nDAYS\nFigure 47: The forecast skill of the control run (solid) and\nthe (unmodified) LAF (dash) . Both the control and\nLAF are T80, and the LAF has 9 members with 6 hour\nspacing, (9 members, 6 hour spacing) .\nNote that\nthe skill of the LAF is worse than the control at\nshorter forecast times.\n82","The evaluation, so far, has focused on predictability as\nit relates to scale interaction processes, particularly in\nblocking and associated cyclogenesis. Diagnoses reveal that\nevolution of the planetary and sub-planetary scale circulations\ncan be, but is not always, dependent upon their interaction with\none another. The degree of this dependence has clear\nimplications on the predictability of the phenomenon in\nquestion. In one case (January 1989) scale interactions\nappeared crucial to the development of a block in the Pacific.\nIn all but one ensemble member, forecasts did not capture this\ndevelopment. In this exception, the phasing and subsequent\ninteraction of planetary and sub-planetary systems (comparable\nto events in the verifying analyses) resulted in an extra-\nordinarily good prediction at the 15-20 day range (figure 48).\n5.2.3 Probability Forecast Experiment (Tracton)\nThe name of this project (formerly the \"spin-off\" test)\nhas been changed because the medium and extended-range\npredictions are intrinsically probabilistic in nature, and\nforecast ensembles are necessary to provide estimates of the\nuncertainties. Beginning in February 1991, the lagged average\nforecast (LAF) ensembles were upgraded from 5 forecasts at 24-\nhr. intervals to 9 members with 6-hr. spacing. In addition,\nthe target period of the LAF ensembles was extended from D+8 to\nD+13. This configuration was implemented on the Cyber computer\nusing the T80 version of the MRF. However, due to the loss of\nthe Cyber in March and time constraints on the new Cray super\ncomputer, the probability forecast extensions were truncated to\nT62 in April. Limited experiments suggested that the T62 model\nis less satisfactory, at least in some cases (e.g. blocking).\nAttempts were made, but were unsuccessful, for\nmodifications to NMC's operational suite which would have\npermitted a return to the T80 model. Although less than\noptimum, the probability experiment is realistic in the sense of\nreflecting the most that can be done in the context of NMC's\noperational environment. Also, this experiment can be viewed as\nthe benchmark for judging possible improved versions pursued\noutside the operational block. Evaluation of the upgraded\nexperiment awaits a longer, more stable sample of cases, e.g.,\nduring the cold season. A comprehensive evaluation of the\nprobability experiment through March 1991 was completed and a\npaper was written for journal publication. The results did not\ndemonstrate any positive influence of the extended runs on CAC's\nMonthly Outlooks of surface temperature anomalies. This was\nattributable, at least in part, to the limited number of members\nand coarseness of spacing within LAF ensemble\n83","h\n$880.\n5839.\nx\n6880.\n6382.\n$880.\n5743\n5040!\n1829\n4920\n$509.\n1025\n4979.\n5753.\n5536\n5659\n5740\n5400.\n5280\n5040.\n9244\n5640\n$20.\n5782.\n$760\n5880\n\"\n5904\nA\nQ\n5804.\n5808.\n5823\n$2.22\n5012\n766.\n5040\n1017\n950\n5812.\nusso.\n80\n5489\n5701.\n5100.\n5520.\n5640.\n5750\nB\n.\nFigure 48: DERF day-18 500mb height from 00Z, 17 January 1989\n(A), and corresponding verification (B).\n84","5.2.4 MRF Model Skill Prediction (Chen)\nIn an effort to increase the capability of predicting\nforecast skill, an examination is being made of Dynamical\nExtended Range Forecast Experiments. The goal is to determine\nif there is any relationship between the skill of\nmedium/extended range forecasts over the Pacific/North America\n(PNA) region and the fluctuations of the PNA mode of low\nfrequency variability. The relationship between the extent of\nthe PNA mode and predictability of the prediction model was also\ninvestigated. The PNA circulation regime in the initial\nconditions as a predictor of forecast skill is contrasted in\ndetail with that in the forecasts. Statistical significance of\nthe relationships was also examined. The results indicate that\nthe PNA mode extent in the forecasts has a much better\ncapability to sort out in a priori the higher-skill forecasts\nfrom the lower-skill forecasts, as shown in figure 49.\nFurthermore, the performance of forecasts for the North\nPacific and North Atlantic sectors were evaluated separately,\nto isolate the effects of El Niño/Southern Oscillation\nanomalies. A number of distinct features were found. Both\ndynamical and persistence forecasts had higher skill for the\nPacific sector than for the Atlantic sector. In addition, a\nsystematic bias towards a positive PNA circulation pattern was\nfound in forecasts at extended ranges. This explains the fact\nthat the average forecast skill over the Pacific sector at\nextended ranges appears significantly above zero.\n5.2.5 MRF Model Behavior and Predictability (Chen)\nIn order to increase the understanding of atmospheric\npredictability, a case study was examined for November 1989.\nDuring November 1-11, a strong zonal flow occurred over the\nNorth Atlantic, followed by a prominent 30-day long blocked\nflow. As shown in figure 50, the flow was still zonal on\nNovember 9 ; but with only 3 days of transition, a well\nestablished blocking pattern can be seen on November 13. The\nbreakdown of this block was as rapid as its establishment.\nFigure 51a shows a block over the North Atlantic on December 5-\n7; then, on December 11-13, this is replaced by strong zonal\nflow (figure 51b).\nThe mechanisms of regime transition and maintenance of\nblocking were diagnosed, using a daily sequence of isentropic\npotential vorticity (IPV) maps. Prior to block development, the\nambient flow field was found to be diffluent and it stretched\nthe embedded disturbances meridionally and compressed them\nlongitudinally. This resulted in a large amount of vorticity\nand temperature exchanges between low and high latitudes,\noverturning the normal north-south IPV gradient and\nestablishing the blocking configuration. Prior to any breakdown\n85","1.0\na\n0.8\n0.6\n0.4\n0.2\n0.0\n1.0\nb\n0.8\n0.6\n0.4\n0.2\n0.0\n-.2\n-.4\n-.6\n0\n5\n10\n15\n20\n25\n30\n1.0\nC\n0.8\n0.6\n0.4\n0.2\n0.0\n-.2\n- 4\n-.6\n0\nS\n10\n15\n20\n25\n30\nFORECAST RANGE (DAY)\nFigure 49: The anomaly correlation skill scores of those\nforecasts being selected by large 15-day-forecast\nPNA mode extent (panel b) ; by small 15-day-forecast\nPNA mode extent (panel c) . Solid curve is the mean\nof each group. Panel a contrasts those two mean\nvalues, where the solid curve is from panel b and\nthe dashed curve from panel C ; the broken curve\nindicates the confidence level of the difference\nbetween those two means.\n86","9 NOV 1989\n0\n5\n10 NOV 1989\nill NOV 1989\n12 NOV 1989\n13 NOV 1989\nFigure 50: Diagram showing rapid transition from a zonal flow\nto a blocking flow regime for Nov. 9-13, 1989. The\ncontours are 540 and 570 dam Z at 500mb. A three-\nday running mean filter has been applied to each\ncontour.\n87","552\nwas\nTeam\nL35\n120\nDiagram showing rapid transition from a blocking flow\nFigure 51:\nto a strong zonal flow regime over the North\nAtlantic. Daily 500mb 552 dam Z contours are for\nDec. 5-7, 1989 (a) and Dec. 11-13, 1989 (b).\nA\nthree-day running mean filter has been applied to\neach contour.\n88","of the block, the diffluence in the ambient flow field\ndiminished dramatically. A depression became longitudinally\nelongated and pierced through the blocked region with high IPV\nair, which prevented low IPV air from being swept to the blocked\narea. Without replenishment of new low IPV air, the previous\nlow IPV air in the blocked area gradually dissipated and\nsubsequently the block disappeared.\n5.2.6 Prediction of Persistent Atmospheric States (Anderson)\nThe objective of this study is to develop a dynamical\nexplanation and conduct a diagnostic test for unusual persistent\natmospheric patterns. First, a robust algorithm was developed\nthat calculates nearly stationary states of the unforced\nbarotropic vorticity equation that are \"close\" to an observed\nglobal atmospheric stream function distribution. The algorithm\nwas then applied to a number of 300mb Northern Hemisphere winter\ninstantaneous and time averaged flows. In all cases studied,\nthe method is able to converge to a nearly stationary state,\none for which a measure of the time tendency has been reduced by\nseveral orders of magnitude. When applied to instantaneous\nflows, the algorithm converges to either relatively zonal or\nstrongly blocked flows, depending on the initial conditions.\nIn almost all cases, observations that have even slight hints of\nblocking converge to strongly blocked nearly stationary flows.\nFigure 52 shows the observed 300mb stream function (for\nJanuary 14, 1987) and the resulting blocked nearly stationary\nstate. When applied to monthly mean flows, and to apparently\nunblocked instantaneous flows, the algorithm converges to\nunblocked, but still wavy, flows. Only the long wave components\nof the observed state need be retained in the initial condition\nin order to converge to nearly stationary blocking states.\nResults of normal mode instability, using the nearly stationary\nstates as basic states, show that even some weakly blocked\nobserved states are in the \"attractor basins\" of strongly\nblocked nearly stationary states. This suggests that these\nstationary states may play some indirect role in the occurrence\nand persistence of blocking states in the real atmosphere.\n5.2.7 Long Series of Extended Range (90-day) Forecasts\n(van den Dool)\nA joint project (with Saha, Kalnay, Kanamitsu/NMC,\nDevelopment Division) was initiated to study seasonal forecasts/\nsimulations using a state-of-the-art general circulation model.\nThe model integrated was a T40 version of the global spectral\nMedium-Range Forecast model that is used operationally (at T80\nresolution) at the National Meteorological Center. The model\nhas 18 vertical levels in the sigma coordinate system and all\nintegrations were carried out on the CRAY-YMP8 supercomputer.\n89","a\n0\nb\nObserved (a) and corresponding nearly stationary (b)\nFigure 52:\nstreamfunctions for January 14, 1987.\n90","The model was integrated out to 90-days from 128 successive\ninitial states (from May 3, 1990 - October 6, 1990). The first\n90-day integration started on May 3 and its 90th day forecast\nverified on August 1, 1990. Similarly, the last 90-day\nintegration started on October 6 and its 90th day forecast\nverified on December 6, 1990. In order to complete a Lorenzian\ndata block, forecasts were also run from initial conditions, but\nwith decreasing forecast lead time. For example,\nthe\nintegration from October 7 was run out to 89 days, and that from\nthe October 8 was run out to 88 days, and so on.\nThe complete output of diagnostic data (reduced form at\nT21 resolution) for each 90-day integration has been archived.\nThe following fields are now available: A) Surface gridded\nfields (2.5 x 2.5 latitude/longitude grid) of total rainfall,\nconvective rainfall, surface temperature, soil wetness, snow\ndepth, sensible heating flux, latent heating flux, and U-and V\nstress flux. B) Spectral files (T21 resolution) of geopotential\nheight, vorticity, divergence virtual temperature (1000-50mb)\nrelative humidity (1000-300 mb) vertical velocity (1000-100 mb)\nand a surface pressure log. Time series of each of the 74\nfields will be archived separately to facilitate fast access\nfrom magnetic tape or optical disk. Figure 53 shows the skill\nof the models for forecast day 1 to 90 averaged over all cases.\nThe anomaly correlation is negligible at day 10 (in the mean),\nand truly zero at day 20.\n5.2.8 Transient Wave Structures in the Atmosphere and In Models\n(Johansson)\nIn this study, the DERF/90 data set (90-day forecasts\nfrom 128 contiguous daily analyses) was used to analyze: 1) the\nstructure of transient baroclinic waves, and 2) the drift of\nthese quantities from those observed for the atmosphere to those\nof the model. It was found that the structure of the baroclinic\nwaves undergo rapid changes during the first 5 to 10 days of\nintegration, as shown in figure 54. Thereafter, the structures\nseem to have reached its statistical equilibrium. The main\ninterest here is that the climate drift in many of the mean\nquantities occur on a much longer time scale. Thus, it is\nhypothesized that fundamental problems exists with the model\nwhich causes the transient waves to obtain erroneous structures\nrapidly. These erroneous structures imply erroneous feedbacks\nto the mean flow and a subsequent equilibration between mean\nflow and transients that is different from what is observed.\nConsequently, the transients are seen as a cause of the climate\ndrift in the mean flow quantities.\n91","Z 500 ( 1AUG90- 6DEC90) 20N-80N ANOMALY CORRELAT\n100\n90\n80\n70\n60\n50\n40\n30\n20\n10\n0\n-10\n90\n80\n40\n50\n60\n70\n0\n10\n20\n30\nFORECAST TIME IN DAYS\n128 (Aug. 1 -Dec. 6, 1990) ninety-day forecasts.\nFigure 53:\nSkill for forecast day 1 to 90 averaged over all\ncases. (Classic verification!)\n92","ZONAL WAVENUMBER\n91.\n20 0\n20\n&\n18.\n7\n20.0\n28.0\n81.\n20\n0\n8\n30\na\n28\nH\n0\n28.0\no\n71.\n28\n2\n15.0\n28.0\n28.0\nH\n28.0\n20.0\n61.\n30.7\n20.\n20\n0\n0\n20\n22\n0\n28\n51.\n20.0\n2\ne\n23.0\nD\n20.0\n20\nH\n28.0\n20.0\n26\n0\n20\n41.\n20.0\n20\n20\no>\nof\n28.\n2\n30.8\n50.0\n0\n20.0\n20.0\n20.0\n31.\n23\na\nZ\n0\n28\na\n28.0\n21.\n20\na\n28\n28\n20.0\n23.0\n11.\n28.\n0\n20\n2\n1.\n1.\n2.\n3.\n4.\n5.\n6.\n7.\n8.\n9.\n18\nThe phase difference between the\nFigure 54:\ngeopotential\nheight and temperature fields for transient\nbaroclinic waves at 500 hPa in the area between 40S\nand 63S. The zonal wave number is on the abscissa\nand forecast lead time in days is on the ordinate.\nThe contour interval is 4.\n93","5.2.9 The Climate in a Multi-Year NMC Model Run (van den Dool)\nThe purpose of this joint study (Saha, NMC/Development\nDivision) is to establish the climate properties of a state-of\nthe-art general circulation model. The model integrated was a\nT40 version of the global spectral Medium-Range Forecast model\nused operationally (at higher resolution) at NMC. The model has\n18 vertical levels in the sigma coordinate system and was\nintegrated for 10 years (3653 days) on the CRAY-YMP8 super\ncomputer from initial conditions on July 31, 1991. The lower\nboundary conditions were as follows: solar radiation, snow\ndepth, soil moisture, sea-ice and sea-surface temperature were\nupdated daily. As far as external conditions were concerned,\n10 identical annual cycles were processed; thus, year-to-year\nvariability can be attributed to the model's internal dynamics.\nMass was generally well conserved with an increase of only 3 mb\nin global mean surface pressure over 10 years.\nA time series of the global mean surface temperature\n(00Z) at all 3653 days is shown in figure 55a. One can see 10\nannual cycles, the highest values occurring in Northern\nHemisphere summer. One can also see a certain amount of\ninterannual variability (note the cold in year 5) In addition,\nthe initial drift is evident, as a drift towards colder values\nsets in from the initial condition. The climatological annual\ncycle was studied in the model, based on 10-year mean monthly\nfields. Figure 55b shows the annual variation of\nhemispherically averaged 500mb height, i.e., the total heat\ncontent below that level. Apart from the cold bias that helps\noffset the curves, the similarity of the annual variation in\nboth hemispheres is remarkably good.\n5.2.10 Systematic Errors in the MRF Model Five-Day Mean 500mb\nHeight Anomaly Predictions (Schechter)\nThis purpose of this study is to determine the nature of\nsystematic errors in the MRF forecasts of five-day mean 500mb\nheight anomaly centers. The spatial distribution of these\nanomaly centers is a key tool used to prepare the 6 to 10 and\n30-day forecasts. So far, forecasts from the MRF model have\nbeen examined for December 1986 - April 1987 and positive and\nnegative anomaly centers were treated separately. Individual\nanomaly centers that met specified criteria were tracked during\neach available MRF model forecast cycle on an interactive\ncomputer system. Verification of anomaly tracks was achieved\nusing 5-day mean 500 mb height analyses, with statistics on the\nanomaly track errors stratified by month and season. Efforts\nare now underway to relate the observed systematic track\nforecast errors to several indices that reflect characteristics\nof the 500mb flow regime present in the initial conditions. An\neffort will also be made to detect any systematic error behavior\nduring blocking episodes.\n94","16.5\nTEMP GLOBAL MEAN\n16.0\n15.5\n15.0\n14.5\n14.0\n13.5\n13.0\n12.5\n12.0\n0\n500\n1000\n1500\n2000\n2500\n3000\n3500\n4000\nFigure 55a: Time series of global mean surface temperature (00Z)\nfor 3653 days.\n5800\n5780\n5760\n5740\n5720\n5700\n5680\n5660\n5640\n5620\n5600\n5580\n5560\n5540\n1\n2\n3\nq\n5\n6\n7\n8\n9\n10\n11\n12\n13\nMONTH\nFigure 55b: The annual cycle in hemispherically -averaged height\nbased on a 10 year climatology. Units are gpm.\nObserved NH (A) , Model NH (B) , Observed SH (c), and\nModel SH (D) .\n95","5.3\nEvaluation\n5.3.1 Operational Outlooks (Livezey, Hoopingarner)\nA program of modernization and automation of forecast\noperations has led to the creation of accessible digital files\nof monthly and seasonal forecasts. These include: forecasts of\nmonthly U.S. temperature and precipitation categories (in three\nclasses) i hemispheric 700mb height anomalies (produced 24 times\na year since 1974) seasonal U.S. temperature and precipitation\ncategories (produced 4 times a year from 1958-1981, and 12 times\na year thereafter). Probability forecasts for Alaska/Canada\nand mid- and high-latitude Eurasia are available since 1987.\nThese data form the basis for a detailed documentation of the\nvariability over time, and by season, location, parameter, and\nclass of the skill of U.S. monthly and seasonal prediction\npractices. Ideally the information generated will not only\nprove useful for management of forecast operations and for the\nforecasters themselves, but also to potential users as part of\ntheir particular decision-making process.\nFor categorical forecasts a skill score that measures\nthe percent of hits above that expected from random forecasts is\nmost heavily employed, while for probability forecasts the rank\nprobability score is used. Time series of map skills,\nincluding dependency of skill on season, maps of local skills,\nand summary contingency tables have been produced for all\nsurface forecasts and have been examined for meaningful\nvariability. An example of such variability is depicted in\nfigure 56, which shows the difference in skill between official\nU.S. monthly mean temperature forecasts and forecasts of\npersistence. The large change in this difference between the\n1970's and 1980's can be partially attributed to improvements in\nglobal numerical weather prediction and has been completely a\nconsequence of cold season forecasts.\nIn the case of 700mb height forecasts, skill was\nexamined by the use of a score based on the percent of\nreduction in mean square error compared to climatology\nforecasts and a decomposition of this score into terms\nrepresenting phase, amplitude, bias, and climatology errors.\nThe results of such an analysis, so far, have exhibited a\nvariety of interesting features. They include: a trend in\nincreasing skills from a reduction in phase errors (mainly\nfrom cold season forecasts); initially weak amplitude errors\nas a result of extremely conservative forecasts, with a recent\nupsurge in these errors because of overly bold forecasts; and a\nmoderately high level of bias error without a break over the\nlast several years (mostly in the Spring and Fall), because of a\ntrend toward a warmer lower troposphere. These analyses are\nbeing augmented by several approaches for examining the regional\nvariability of the various sources of error.\n96","Monthly Forecast Skill\nOFF - OPR Difference Temperature\n30\nOFF\n25\nPre-GNWP\nPost-GNWP\n20\nMean\n15\n10\n5\n0\n-5\n-10\n-15\n74 75 76 77 78 79 80 81 82 83 84 85 86 87\n88\n89\n90\nDate\nFigure 56: Skill differences for monthly mean U.S.\nsurface\ntemperature forecasts.\n97","Operational Products\n5.4\n5.4.1 Six-to-Ten Day Forecasts (Hughes)\nThe skill of the operational 6-10 day U.S. temperature\nand precipitation forecasts (as measured by the Heidke Skill\nscore) were above the long-term average (1979/80 - 1989/90) for\neach season, except Winter for the former (figure 57), and Fall\nfor the latter (figure 58). Also, the skill of the 500mb prog\nfor North America (as measured by the normalized correlation\nscore) was above the long term average for each season (see\nfigure 59)\n5.4.2 Monthly Outlook (O'Lenic)\nThe monthly temperature forecasts were most skillful\nduring the spring and summer of 1991. Unlike the seasonal\nforecasts, the monthly forecasts captured, fairly well, the\nunusual warmth that characterized both seasons. One outstanding\nforecast (by S. Tracton), had a skill score of 78, a new record\nfor monthly forecasts. (Most of the other forecasts during\nthat period had skills in the 15-20 range.) This forecast is\nparticularly interesting, since it strongly opposed persistence.\nForecast skill for the months of April, May, and June 1991 were\nin the 20-30 range.\n5.4.3 Seasonal Outlook (O'Lenic)\nThe seasonal temperature forecasts for the U.S. had their\nhighest skill during Fall 1990 and Summer 1991. Skill was also\nhigher, in almost all seasons, for the eastern third of the\ncountry than for the central and western portions. This was\nlikely due to an unusually persistent warm period which spanned\nvirtually the entire year. This persistent pattern resulted in\npreponderance of above normal observed seasonal temperatures\na\nat stations where seasonal forecasts are verified. In the long\nrun, of course, there is a more equitable distribution of\nobserved temperature categories at a given station.\nUnder the conditions observed during the last year, a\nstatistically-based forecast technique suffers, since it will\ntend to generate an equitable distribution of above and below\nnormal categories. The upswing in skill scores during Summer\n1991 indicates that the forecasters had caught on to the trend\nin temperature and were relying more on persistence.\n5.4.4 Modernization of Forecast Operations (O'Lenic)\nA number of tasks were performed in regard to the\nmodernization and security of CAC's 6-10 day forecast operation.\nThe first step was to install an Intergraph workstation, which\nwas achieved with teamwork between CAC and NMC/Automation\n98","OFFICIAL D+8 TEMPERATURE\n36\n1990/91\n32\n1979/80-1989/90\n28\n24\n20\n16\n12\n8\n4\n0\nDJF\nMAM\nJJA\nSON\nSEASON\nFigure 57: Average Heidke skill score for 63 U.S. stations from\nCAC's 6-10 day temperature forecasts. The hatched\nbar graph shows the skill for each season for the\nlatest year. The solid bar graph shows the average\nskill for the years 1979/80 - 1989/90.\n99","OFFICIAL D+8 PRECIPITATION\n22\n1990/91\n20\n1979/80-1989/90\n18\n16\n14\n12\n10\n8\n-\n6\n1\n4-\n2\n-\n0\nDJF\nMAM\nJJA\nSON\nSEASON\nFigure 58: Average Heidke skill score for 100 U.S. stations\nfrom CAC's 6-10 day precipitation forecasts. The\nhatched bar graph shows the skill for each season\nfor the latest year. The solid bar graph shows the\naverage skill for the years 1979/80 - 1989/90.\n100","OFFICIAL D+8 500MB HEIGHT\n68\n1990/91\n64\n1979/80-1989/90\n60\n56\n52\n48\n44.\n40\n36\n32\n28\n24\n20\n16\n12\n8\n4.\n0\nDJF\nMAM\nJJA\nSON\nSEASON\nFigure 59: Average normalized correlation score for 130 NMC grid\npoints over NOAM and vicinity from CAC's 6-10 day\n500 mb height progs. The hatched bar graph shows\nthe skill for each season for the latest year.\nThe solid bar graph shows the average skill for the\nyears 1979/80 - 1989/90.\n101","Division. Techniques had to be developed and implemented which\nincorporated the workstation into the heart of the forecast\nprocess. The workstation is not only used in the development\nand dissemination of 6-10 forecast products, but is the key to\ntheir secure storage during an embargo prior to dissemination.\nAlso, physical and automated controls were developed and\nimplemented in a short time span to protect sensitive forecast\nproducts and tools from being accessed by unauthorized persons.\nThe physical controls include actions to be employed by\nforecasters and modifications to workspaces. The automated\ncontrols run the gamut of NMC hardware and software.\nIn\naddition, a paradigm for forecast security was developed which\nshould facilitate the evaluation of security requirements in a\nwide array of settings. Finally, a plan has been developed that\nwill gradually shift forecast operations from one which is\nheavily dependent upon printed maps, to one in which forecast\nmaterials are created, stored, and viewed on a workstation.\n5.4.5 A Circulation-Based Check on U.S. Temperature Trends\n(van den Dool, 'Lenic)\nperfect prog technique for computing surface\nA\ntemperatures from observed monthly mean 700mb height anomalies\n(developed by W. Klein/University of Maryland) has been used as\na 30-day forecast tool for many years. For several years now,\nthis product has produced temperatures with quite a noticeable\ncold bias over much of the United States (figure 60). If some,\nas yet unspecified, process were progressively warming the\nclimate, it would, given a stable vertical temperature\nstratification, manifest itself first in warmer surface\ntemperatures. Under unstable temperatures stratification, this\ninitial warm temperature anomaly would be rapidly dispersed\nthroughout the troposphere, through the actions of convection\nand large-scale atmospheric motions. If indeed the warming is\nconfined to the lower troposphere, it would have little effect\nupon large-scale, middle-tropospheric circulation regimes for\nsome time. If this is true, then a given circulation regime\nwill tend to be associated with warmer surface temperatures\nduring the later, warmer period than in earlier years.\nThe above scenario is just what the cold-bias of the\nperfect prog surface temperatures seems to indicate.\nTo\ninvestigate this hypothesis, a time series of perfect prog\nsurface temperatures over the U.S. was computed for 1951-91 and\ncompared with observed temperatures during the same period.\nSince the perfect prog equations were developed from 1948-81\ndata, the temperature residuals (perfect prog minus observed)\nare expected to be fairly small during the 1950-81 period.\nHowever, if the later years of the 1980's have experienced a\nwarming, a cold bias, growing as the 1980's progress, should\ncharacterize the time series of the residuals. As shown in\nfigure 61, this is exactly what appears to be happening. This\ntime series will now be extended in time and expanded in area.\n102","Temperature Specifications Std Error\nMar 1991\n06\n12\n16\nto\n4\n:-22\n-15\n7,\nor\n16\n4ON\nin\n-16\n8\n15\n-17\n-\n2\no\n-15\n10\n3\n-18\n-\n6\n10\ne\n10\n15\n22\n17\n2\n14\n-13\n6\n9\n5\n3\n-13\n12\n18\n13\n11\n5\n- 19 -16\n-8\n-9\n-11\n2\n-5\n-13\n-9\n-14\n6\n10\n-4\n0\n10\ng\n-7\n30N\nQ\n-6\n0\n4\n8\nInD\n-9\n5\n0\nP2\n20N\n115W\n95W\n75W\nFigure 60: Standard error of surface temperature specifications\nfrom perfect prog technique for March 1991.\n103","Surface T Residuals, 1981-91\n1.00\n0.90\n0.80\n0.70\n0.60\n0.50\n0.40\n0.30\n0.20\n0.10\nU\n0.00\n-0.10\n-0.20\n-0.30\n-0.40\n-0.50\nE\n-0.60\n-0.70\n-0.80\n-0.90\n-1.00\n8101 8201 8301 8401 8501 8601 8701 8801 8901 9001 9101\nYrMo\nFigure 61: Surface temperature residuals (perfect prog minus\nobserved) for 1981-1991 - period. Temperature is °c.\n(Data are plotted at monthly intervals.)\n104","5.5\nSupporting Projects\n5.5.1 Anomaly History and Teleconnections (Wagner)\nMaps of monthly and seasonal U. S. temperature and\nprecipitation anomalies were produced from the CAMS data set,\nfor years prior to 1947 when 700mb data were either unavailable\nor unreliable. Even without accompanying 700mb height and\nanomaly maps, the temperature and precipitation patterns are\nuseful for selecting specification analogs for monthly and sea-\nsonal precipitation forecasts based on the predicted\ntemperature pattern. Thus far, maps have been completed for\nthe months May through November back to 1915, and for the\nseasons May-July through October-December back to 1901.\nMaps from the CAMS data set display large-scale patterns\nthat are basically similar to older analyses during the 1930's\nand 1940's. However, noticeable differences occur when the\npatterns are relatively flat with extensive areas in the near\nnormal or moderate category. Differences also show up in the\nsouthwestern U.S. where recent climate trends, due to urban\nwarming at several fast-growing cities, have induced an\nartificial cold bias in the earlier part of the temperature\nrecord. This is due to the fact that the values are referenced\nto 1951-80 normals used in the CAMS data set.\n5.5.2 Long-Lead Seasonal Forecasts (Wagner)\nTen years of quasi-real-time, experimental, long-lead\nforecasts of U.S temperature were completed and verified for\nthe four meteorological seasons. The three-class Heidke skill\nscores (table 3) show that there is useful forecast information\navailable at long lead times, particularly for the spring and\nsummer seasons. The columns labeled \"Forecast\" give scores for\nsubjectively made forecasts, using both lag correlations of 700\nmb height and persistence of surface temperature anomaly for all\nseasons up to and including that lead time. The columns labeled\n\"Persistence\" used only the surface temperature anomaly pattern\nfor that particular season.\nThe skill significance was determined by use of a\nMonte Carlo distribution of skill scores obtained by cross-\nmatching the available seasonal forecasts with all observed\ntemperature patterns through 1983. The upper skill significance\nindicator includes artificial skill due to biases and climate\ntrends at certain stations, particularly in the southwestern\nU.S. , whereas the lower indicator estimates the true\nsignificance without the artificial skill. It is evident that\nmost of the skill is robust enough to hold up even without the\nhelp of artificial skill.\n105","10-YEAR AVERAGE THREE-CLASS HEIDKE SKILL SCORES OF EXPERIMENTAL LONG-LEAD SEASONAL TEMPERATURE FORECASTS\n2-SEAS LEAD\n10- YEAR\n2-YEAR\n2-YEAR LEAD\n1-YEAR\n1-YEAR LEAD\n3-SEASON\n3-SEAS LEAD\n2-SEASON\nPERSISTENCE\nFORECAST\nSEASON\nCLIMATOLOGY\nPERSISTENCE\nFORECAST\nFORECAST\nPERSISTENCE\nFORECAST\nPERSISTENCE\n**\n**\n*\n12.5\n10.3\n14.6 *\n18.7\n18.6\nSUMMER\n13.6\n3.7\n10.2\n16.9\n*\n*\n12.9 *\n8.6\n11.7\n16.4 *\n12.6\n7.2\n6.1\nFALL\n7.0\n5.9\nWINTER\n3.5\n11.1\n5.6\n4.8\n17.1\n7.4\n8.5\n3.3\n8.6\n*\n***\n*\n12.6 :\n14.0\n24.8\n11.8 *\n17.2\n7.9\nSPRING\n19.1\n**\n6.1\n7.7\n*** Skill significant at 99.9% level\n*\nSkill significant at 95% level\n** Skill significant at 99% level\nTable 3:\nTen - year average three-class Heidke skill scores of\nexperimental long-lead - seasonal temperature forecasts.\n106","6. SUMMARIES\nClimate and Global Change Program (Rodenhuis, Ropelewski,\n6.1\nvan den Dool, Livezey, Mo, Janowiak, Miller)\nThe primary focus of Climate and Global Change activities\nat the CAC is on climate diagnostics, climate monitoring, and\nclimate trends. The accomplishments for related tasks are\ndescribed in preceding sections of this report. They include:\nSections 1.2.3; 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.2.1, 2.2.2; 3.2.1,\n3.2.2; and 4.5.2.\nCAC is a participant in a number of FY 1991 Tier I\nProjects under the NOAA Climate and Global Change Program.\nThese include: Stratospheric Monitoring and Data Management\n(with ERL), Vegetation Index (with NESDIS) Climate Data\nAssimilation System (with NMC), Global Climate Perspectives\n(with NESDIS), Global Precipitation Climatology Project (with\nWMO/WCRP), and DERF (with ERL, GFDL, and NMC).\nIn addition to the above Projects, CAC staff have either\noriginated or collaborated in a number of new proposals that\nwere submitted to the Office of Climate and Global Change for FY\n1992 funding. These include: Empirical Prediction of ENSO\nFluctuations, North American Land Surface/Atmospheric Hydrologic\nCycle, Development, Soil Moisture and Temperature Predictions\nOver the U.S., Operational Climate Satellite Data Base,\nObjective Extratropical Empirical Prediction on Seasonal Time\nScales, and CD-ROM Center for Climate Applications.\nTOGA Activities (Diagnostics Branch staff)\n6.2\nThe primary focus of TOGA activities at the CAC is on\noperational monitoring of the ENSO and oceanic-atmospheric\nfluctuations. The accomplishments for related tasks are\ndescribed in preceding sections of this report. They include:\nSections 1.1.1, 1.2.4.1; 2.1.5, 2.3.1, 2.3.2, 2.3.3; and 2.4.1.\nCAC staff (Ropelewski) attended and participated in a\nTOGA ENSO Prediction Workshop, Silver Spring MD, Dec. 12-13,\n1990. Also, Ropelewski attended a TOGA Panel Meeting (Jan. 23,\n1991) and presented a briefing on the current state of the\nSouthern Oscillation.\nEPOCS Activities (Diagnostics Branch staff)\n6.3\nThe primary focus of EPOCS activities at the CAC is on\ndiagnostic studies of the tropical oceanic-atmospheric\ncirculation. The accomplishments for related tasks are\ndescribed in preceding sections of this report. They include:\nSections 1.2.1, 1.2.2; and 2.1.5.\n107","Proposals that were approved by the EPOCS Program Office\nfor support in FY 1991 included: Associated Global Circulation\nChanges\" (Ropelewski and Chelliah, and \"Atmospheric\nTeleconnection Dynamics During the 1986-90 ENSO Cycle\" (Mo and\nRasmusson, P.I's). An EPOCS proposal, entitled \"Diagnostics\nStudies of the Coupled Ocean-Atmosphere System,\" (Ropelewski,\nChelliah, and Smith, P.I.'s ) was submitted for FY 92 funding.\nAn EPOCS Panel Meeting (held in Miami, FL, January 21-24,\n1991) was attended by Ropelewski, who accepted an invitation to\njoin the EPOCS Advisory Council.\nBilateral Activities\n6.4\n6.4.1 U.S.-Brazil Bilateral Agreement (Kousky)\nUnder the auspices of the U.S. - Brazil Bilateral\nAgreement for Science and Technology, Ms. C. Ferreira, from the\nCeara Foundation of Meteorology and Water Resources, completed\nher 4-month stay at NMC's South American Desk in June; Dr. M.\nKayano, from the Brazilian National Institute of Space research,\nvisited the CAC from January - May; J. C. Figueiredo, from the\nInstitute of Meteorological Research in Brazil, began a three\nmonth visit to the South American Desk in August 1991. These\nvisiting scientists participate in the preparation of numerical\nforecast discussions, which are disseminated on the Global\nTelecommunications System (GTS) to all South American countries,\nand in forecast evaluation studies.\nAt the beginning of each month a description is prepared\n(by Kousky) concerning the current climate anomalies in the\ntropical Pacific and disseminated via the GTS to South American\ncountries.\nUnder the bilateral agreement, Kousky participated, as\nrapporteur, in a Workshop on the Relationship of the Atlantic to\nRegional and Global Climate Variations. This Workshop was held\nin Fortaleza, Brazil, October 1-5, 1990.\n6.4.2 U.S. - Soviet Bilateral Agreement (Rodenhuis, Barnston,\nLivezey, Ropelewski)\nUnder the activities of Working Group 8 of the U.S\n-\nSoviet bilateral agreement, there was a successful outcome of a\njoint project/exchange between the USSR Hydrometeorological\nCenter and the CAC. Preparatory work (A. Barnston) took place\nin Moscow in 1990 to conduct experiments that would compare\nanalog prediction technologies developed at the respective\ncenters. This work culminated in the completion of several of\nthese experiments at CAC (R. Livezey) during the working visit\nof Professors G. V. Gruza and E. Ya. Rankova (Institute for\nGlobal Climate and Ecology, Moscow, USSR) during early 1991.\n108","Three Soviet scientists attended the 15th Annual Climate\nDiagnostics Workshop, held in Asheville, NC, October 28 -\nNovember 1, 1990.\nThe annual planning meeting for Working Group 8 was held\n(Leningrad, USSR in January 1991) to prepare a plan for\nscientific exchange in the following year. D. Rodenhuis\nparticipated as leader of Project 8.11, Climate Change. Also,\npreparations were made for the upcoming Workshop on Hydrology\nand Climate Monitoring (Leningrad, USSR) in October 1991. A\npresentation is planned (by D. Rodenhuis ) on regional climate\nmonitoring and revised plans for the project in the coming year.\nAlso, efforts were made (C. Ropelewski) to exchange\nclimate anomaly data in near-real-time with the World Data\nCenter B at Obninsk, USSR using the San Francisco/Moscow\nteleport link.\n6.5\nWorld Climate Program Activities\n6.5.1 Climate System Monitoring (Kousky, Rodenhuis, Ropelewski)\nThe CAC provided data, graphics and analysis support for\nthe WMO's third Climate System Monitoring biennial review.\nAnalyses of the significant global surface temperature and\nprecipitation anomalies were also provided by CAC's Analysis and\nInformation Branch. In addition, the CSM Monthly Bulletin\n(published by the World Climate Program) contains a large amount\nof CAC products. The CSM/Working Group Meeting (held in\nHelsinki, Finland, August 1991) was attended by V. Kousky.\nCAC staff (Rodenhuis and Ropelewski) participated in\nplanning activities of the WMO Climate Change Detection Project.\n6.5.2 Global Precipitation Climatology Project (Janowiak)\nThere were several activities associated with the Global\nPrecipitation Climatology Project (GPCP) which is supported by\nthe NOAA/Climate and Global Change Initiative. Among these\nactivities were: participation in the GPCP Working Group for\nData Management (Laurel, MD , May 1991) i participation in,\ncoordination of, and the production and dissemination of results\nfrom the GPCP/Algorithm Intercomparison Project I; and a\npresentation of a comparison between NMC and ECMWF model\nprecipitation forecasts with GPCP rainfall estimates at the \"NMC\nRe-analysis Workshop\" (Camp Springs, MD, April 1991).\n109","6.5.3 Global Energy Water Cycle Experiment (GEWEX) (Janowiak,\nRopelewski)\nA workstation and data have been received at the CAC for\n\"Wetnet\" - related studies. J. Janowiak agreed to be a steering\ncommittee co-chairperson for the \"Precipitation Intercomparison\nProgram\". This Program is a WETNET activity that will compare\nprecipitation estimates derived from microwave (SSM/I) data.\nA proposal for a joint study (with E. Rasmusson, Univ. of\nMaryland/CICS) was submitted to the NOAA Office of Climate and\nGlobal Change for funding. The purpose of the study is to\nprovide an improved diagnosis of continental-scale atmospheric/\nsurface hydrologic balances over the U.S. and southern\nto derived from routinely acquired data. This project is designed Canada,\nfold into the GEWEX/Continental International Program.\n6.5.4 Intergovernmental Panel for Climate Change (IPCC)\n(Ropelewski, Chelliah)\nCAC provided a number of parameters as input to the IPCC\nupdate report. These include: Outgoing Longwave Radiation data,\nand uncertainties in global estimates of sea surface temperature,\nsea ice and snow cover totals.\n6.5.5 Commission on Climatology (CC1) (Rodenhuis, Ropelewski)\nAlthough no meetings of the Commission or its Advisory\nthe Committee were held, there were ad hoc working group meetings on\nEarly Detection of Climate Change. As a result of\nmeetings, recommendations were considered by the WMO Executive these\nCommittee. is Subsequently, an international Working Group\nplanned for October 1991, in Geneva Switzerland. Preparations Meeting\nare being made for the meeting (by Ropelewski).\n6.6\nNational Weather Service Programs\n6.6.1 Data Management (Rodenhuis)\nCAC staff (Ropelewski) participated on the NMC Committee\ninitiated for Data Base Management. Also, a cooperative effort\n(with C. Mass, Univ. of Washington ) to create was and\ndistribute NMC climate-related data on CD-ROM optical disks.\n6.6.2 ASOS Climate Working Group (Rodenhuis, Ropelewski)\nA special session on ASOS was held at the 15th Annual\nClimate Diagnostics Workshop (Asheville, NC, November 1990) The\nthe ASOS/CWG met to discuss the use of supplemental observations . and\nimpact of ASOS on climate observations. A draft \"ASOS\nClimate Plan\" was circulated for comment.\n110","Two projects were initiated to intercompare ASOS with\n\"conventional\" data in the central United States. The first one\nis under the direction of the Dr. T. McKee (Colorado State\nUniversity) and the second one by Dr. T. Karl (NESDIS/NCDC)\nBoth are funded by the NOAA/Earth System Data and Information\nManagement Project\nAnnual Climate Diagnostics Workshops\n6.7\n6.7.1 Fifteenth Annual Climate Diagnostics Workshop (Rodenhuis,\nRopelewski)\nThe NMC/Climate Analysis Center and NESDIS/National\nClimatic Data Center were co-sponsors of the Fifteenth Annual\nClimate Diagnostics Workshop, held in Asheville, NC (October 29-\nNovember 2, 1990). These Workshops provide a forum for\nresearchers to present recent results and to exchange ideas on a\nvariety of climate topics. This meeting focused on: Recent\nClimate Anomalies; ENSO; Interannual, Intraseasonal, and Low-\nFrequency Variability; Climate Data Sets; Ocean-Atmosphere\nInteractions; Climate Impacts and Studies; and Climate\nPrediction. There were 95 presentations; a Proceedings was\npublished and distributed in March 1991.\n6.7.2 Sixteenth Annual Climate Diagnostics Workshop (Rodenhuis,\nMo)\nArrangements were completed to hold the Sixteenth Annual\nClimate Diagnostics Workshop in Lake Arrowhead, CA. The UCLA/\nDept. of Meteorology has agreed to co-host the Workshop which\nis scheduled for October 28 - November 1, 1991. Preparations\nincluded: invitations to the Workshop and a Workshop\nannouncement published in the Bulletin of the AMS (June 1991).\n111","THIS PAGE INTENTIONALLY LEFT BLANK\n112","7. BIBLIOGRAPHY\n7.1 Journal Articles\nBarnes, R. A. L. R. McMaster, W. P. Chu, M. P. McCormick and M.\nE. Gelman, \"Stratospheric Aerosol and Gas Experiment II and\nROCOZ-A ozone profiles at Natal, Brazil: A basis for\nComparison with other satellite instruments,\" Journal of\nGeophysical Research, 96, 1991, pp. 7515-7529.\nBarnston, A. G. , \"An empirical method of estimating raingage and\nradar measurement bias and resolution,\" Journal of Applied\nMeteorology, 30, 3, 1991, pp. 282-296.\nBarnston, A. G. and R. E. Livezey, \"Statistical prediction of\nJanuary-February mean Northern Hemisphere lower\ntropospheric climate from the 11-year solar cycle and the\nSouthern Oscillation for west and east QBO phases,\" Journal\nof Climate, 4, 1991, pp. 249-262.\nBarnston, A. G. R. E. Livezey and M. S. Halpert, \" Modulation\nof Southern Oscillation-Northern Hemisphere mid-winter\nclimate relationships by the QBO, 11 Journal of Climate, 4,\n1991, pp. 203-217.\nCai, M. and H. M. van den Dool, \"Low-frequency waves and\ntravelling storm tracks-Part I: Barotropic component, \"\nJournal of the Atmospheric Sciences, 48, 1991, pp. 1420-\n1436.\nEpstein, E. S. \"On obtaining daily climatological values from\nmonthly means,\" Journal of Climate, 4, 1991, pp. 365-368.\nGhil, M. and K. Mo, \"Intraseasonal oscillations in the global\natmosphere, Part I: Northern Hemisphere and Tropics, 11\nJournal of the Atmospheric Sciences, 48, 5, 1991, pp. 752-\n779.\nGhil, M. and K. Mo, \"Intraseasonal oscillations in the global\natmosphere, Part II: Southern Hemisphere, \" Journal of the\nAtmospheric Sciences, 48, 5, 1991, pp. 780-790.\nJanowiak, J. E. and P. A. Arkin, \"Rainfall variations in the\ntropics during 1986-89, as estimated from observations of\ncloud-top temperature,\" Journal of Geophysical Research,\n96, Feb. 1991, pp. 3359-3373.\nKanamitsu, M. K. Mo and E. Kalnay, \"Annual cycle integration of\nthe NMC Medium Range Forecasting (MRF) model,\" Monthly\nWeather Review, 118, 1990, pp. 2543-2567.\nKayano, M. T. and V. E. Kousky, \"Southern Hemisphere blocking:\nA comparison between two indices, Meteorology and\nAtmospheric Physics, 42, 1990, pp. 165-170.\n113","Kousky, V. E. and M. S. Halpert, \"The global climate of March-\nMay 1990: An abnormally warm season in both hemispheres,\"\nJournal of Climate, 4, 1991, pp. 80-105.\nLe Comte, D. M. \"Weather of 1990: Highlights in the United\nStates, \" Weatherwise, 44, 1, 1991, pp. 8-12.\nLe Comte, D. M., \"Weather of 1990: Highlights around the\nworld,\" Weatherwise, 44, 1, 1991, pp. 13-16.\nMo, K. J. R. Zimmerman, E. Kalnay and M. Kanamitsu, \"A GCM\nstudy of the 1988 United States drought,\" Monthly Weather\nReview, 119, 1991, pp. 1512-1532.\nvan den Dool, H. M. \"Mirror images of atmospheric flow, \"\nMonthly Weather Review, 119, 1991, pp. 2095-2106.\nvan den Dool, H. M. and Z. Toth, \" Why do forecasts for 'near\nnormal' often fail?,\" Weather and Forecasting, 6, 1991,\npp. 76-85.\nWagner, A. J. , \"Northern Hemisphere steering currents,\"\nWeatherwise, 44, 1, 1991, pp. 17-21.\n114","7.2 Articles in Non-Refereed Literature*\nBarnston, A. G. and E. S. Epstein, \"An imperfect prog technique\napplied to 6-10 day forecasts: Predictability of the\npredictor fields,\" Proceedings of the 15th Climate\nDiagnostics Workshop, Asheville, NC, October 29-November 2,\n1990, pp. 468-474.\nBermowitz, R. J. , J. D. Laver and D. R. Rodenhuis, \"National\nWeather Service management of the Regional Climate Center\nProgram, Preprint Volume: AMS Seventh Conference on\nApplied Climatology, Salt Lake City, UT, September 10-13,\n1991, pp. 214-220.\nCai, M. and H. M. van den Dool, \"Relationship between low\nfrequency waves and high frequency eddies, Proceedings of\nthe 15th Climate Diagnostics Workshop, Asheville, NC,\nOctober 29-November 2, 1990, pp. 197-201.\nChelliah, M. \"Circulation variability associated with outgoing\nlongwave radiation on the monthly to seasonal time scale, \"\nProceedings of the 15th Annual Climate Diagnostics\nWorkshop, Asheville, NC, October 29-November 1990, pp. 149-\n154.\nChen, W-Y. , \"Rapid establishment and demise of a 30-day long\nAtlantic blocking anticyclone, \" Proceedings of the 15th\nClimate Diagnostics Workshop, Asheville, NC, October 29-\nNovember 2, 1990, pp. 173-180.\nEpstein, E. S. and W. H. Klein, \"An imperfect prog technique\napplied to 6-10 day forecasts: General methodology,\"\nProceedings of the 15th Climate Diagnostics Workshop,\nAsheville, NC, October 29-November 2, 1990, pp. 462-467.\nFolland, C. K. R. W. Reynolds, M. Gordon and D. E. Parker, \"The\nWMO-sponsored intercomparison of SST data sets for long-\nrange Forecasting,\" Proceedings of the 15th Climate\nDiagnostics Workshop, Asheville, NC, October 29-November\n2, 1990, pp. 225-230.\nGelman, M. E. , \"Stratospheric monitoring With TOVS data, \"\nPalaeogeography, Palaeoclimatology, Palaeoecology, (Global\nand Planetary Change Section), Elsevier Science Publishers\nB. V. Amsterdam. 90, 1991, pp. 75-78.\nHalpert, M. S. , \"Climate monitoring using an AVHRR-based\nVegetation Index,\" Palaeogeography, Palaeoclimatology,\nPalaeoecology, (Global and Planetary Change Section),\nElsevier Science Publishers B. V., Amsterdam. 90, 1991, pp.\n201-205.\n(In this Section, 37 of the references also included a\n*\npresentation at a formal scientific meeting.)\n115","Halpert, M. S. and C. F. Ropelewski (Editors), , \"Climate\nAssessment: A decadal review, 1981-1990,\" CAC Report, March\n1991, 109 pp.\nHalpert, M. S. , C. F. Ropelewski and J. Burelbach, \"Global\nvegetation during 1990,\" Proceedings of the 15th Annual\nClimate Diagnostics Workshop, Asheville, NC, October 29-\nNovember 2, 1990, pp. 22-25.\nHeddinghaus, T. R., \"Monitoring and dissemination of drought\nconditions at the Joint Agricultural Weather Facility,\"\nProceedings of the Seminar and Workshop:\nDrought\nManagement and Planning Conference, (Denver, CO, May 30-\nJune 1, 1990), IDIC Technical Report Series 91-1,\nUniversity of Nebraska, Lincoln, NE, 1991, pp. 67-72.\nHeddinghaus, T. R. and P. Sabol, \"A review of the Palmer\nSeverity Index and where do we go from here,\" Preprint\nVolume: AMS/Seventh Conference on Applied Climatology,\nSalt Lake City, UT, September 10-13, 1991, pp. 242-246.\nHoopingarner, J. K. and Livezey, R. E. , \"Digitization and\nverification of a twenty-year archive of hemispheric,\nmonthly mean, 700 mb height forecasts, \" Proceedings of the\n15th Climate Diagnostics Workshop, Asheville, NC, October\n29-November 2, 1990, pp. 482-484.\nHughes, F. D. , \"Skill of Medium Range Forecasts,\" NMC Office\nNote 377, February 1991, 32 pp.\nJanowiak, J. E. , \"A comparison between satellite-based rainfall\nestimates and the NMC model rainfall in the tropics, \"\nProceedings of the 15th Annual Climate Diagnostics\nWorkshop, Asheville, NC, October 29-November 2, 1990, pp.\n263-268.\nJanowiak, J. E. , \"The reliance on operational weather satellites\nfor the global precipitation climatology, Palaeogeography,\nPalaeoclimatology, Palaeoecology, (Global and Planetary\nChange Section), Elsevier Science Publishers B. V ,\nAmsterdam. 90, 1991, pp. 93-98.\nKousky, V. E. \"The evolution of recent oceanic and atmospheric\nanomaly fields in the tropical Pacific, Proceedings of\nthe 15th Annual Climate Diagnostics Workshop, Asheville,\nNC, October 29-November 2, 1990, pp. 1-10.\nLaver, J. E. , \"Monitoring and dissemination activities at the\nClimate Analysis Center, Proceedings of the Seminar and\nWorkshop: Drought Management and Planning Conference,\n(Denver, CO, May 30- June 1, 1990), IDIC Technical Report\nSeries 91-1, University of Nebraska, Lincoln, NE, 1991, pp.\n35-40.\n116","LeComte, D., \" Using intertropical discontinuity to monitor the\nSahel growing season,\" Preprint Volume: AMS Seventh\nConference on Applied Climatology, Salt Lake City, UT,\nSeptember 10-13, 1991, pp. 71-72.\nLehman, R. E. / \"Quick projections for multiple stations (QPMU):\nSystem overview, \" Preprint Volume of the AMS Seventh\nInternational Conference on Interactive Information and\nProcessing Systems , New Orleans, LA, January 14-18, 1991,\npp. 261-264.\nLehman, R. E. and H. E. Warren, \"Accurate climatological tools\nfor projecting monthly gas sales and monitoring annual\nconservation trends,\" Preprint Volume: Conference on PC\nApplications in the Gas Industry, (sponsored by the\nInstitute of Gas Technology) Chicago, IL, May 6-8, 1991,\nSession 4, pp. 1-55.\nMarsico, D. C. and R. W. Reynolds, \"An improved SST analysis\nusing sea ice data,\" Proceedings of the 15th Annual\nClimate Diagnostic Workshop, Asheville, NC, October 29-\nNovember 2, 1990, pp. 247-252.\nMiller, A. J. \"Monitoring the stratosphere with satellites and\nthe Network for Detection of Stratospheric Change, \"\nPalaeogeography, Palaeoclimatology, Palaeoecology, (Global\nand Planetary Change Section), Elsevier Science Publishers\nB. V., Amsterdam. 90, 1991, pp. 69-71.\nMo, K. and E. Kalnay, \" A simple rule of thumb to determine\nwhether an SST anomaly is a result or the cause of an\natmospheric anomaly, WMO World Climate Reseach Programme\nReport No. 14, WMO/TD No. 396, 1991, pp. 42 - -43.\nMo, K. and E. M. Rasmusson, \"Atmospheric water vapor transport\nas evaluated from NMC analyses, Proceedings of the 15th\nAnnual Climate Diagnostics Workshop, Asheville, NC, October\n29-November 2, 1990, pp. 308-313.\nO'Lenic, E. A. \"Regional skill of official NWS monthly and\nseasonal outlooks, Proceedings of the 15th Climate\nDiagnostics Workshop, Asheville, NC, October 29-November 2,\n1990, pp. 495-504.\nO'Lenic, E. A. \"Short -term climate prediction in the Great\nLakes Region,\" Proceedings of the Great Lakes Commission\nSymposium: Great Lakes Water Levels Forecasting and\nStatistics for Decision Making, (Windsor, Ontario, May 17,\n1990), 1991, pp. 27-40.\nO'Lenic, E. A., \"The April-May-June weather outlook and other\nprecursors of Summer 1991,\" Office of Energy Emergency\nAfter-Action Report, Department of Energy, Washington,\nD.C., June 1991, pp. 1.\n117","Planet, W. G. , H. D. Bowman, J. H. Lienesch, A. J. Miller, and\nR. M. Nagatani: \"Long-term ozone measurements from NOAA\nEnvironmental Satellites, Preprint Volume of AMS/Second\nSymposium on Global Change Studies, New Orleans, LA,\nJanuary 14-18, 1991, pp. 93-95.\nReale, A. L., H. E. Fleming, D. Q. Wark, C. S. Novak, F. S.\nZbar, J. R. Neilon, M. E. Gelman and H. J. Bloom, \"Baseline\nUpper Air Network (BUAN) Final Report\", NOAA Technical\nReport NESDIS 52, October 1990, 57 pp.\nReynolds, R. W. , \"Sea surface temperature analyses from in situ\nand satellite data,\" Palaeogeography, Palaeoclimatology,\nPalaeoecology, (Global and Planetary Change Section)\nElsevier Science Publishers B. V., Amsterdam. 90, 1991, pp.\n183-187.\nReynolds, R. W. and A. Leetmaa, \"Data assimilation - tropical\noceans, \" Proceedings of the International TOGA Scientific\nConference - WCRP 43, Honolulu, HI, July 1990, pp. 9-18.\nRopelewski, C. F. , \"Real-time monitoring of global snow cover,\nPalaeogeography, Palaeoclimatology, Palaeoecology, (Global\nand Planetary Change Section), Elsevier Science Publishers\nB. V., Amsterdam. 90, 1991, pp. 225-229.\nRopelewski, C. F. \"Building a satellite climate diagnostics\ndata base for real-time climate monitoring, \" Proceedings of\nthe Second Symposium on Global Change Studies, New Orleans,\nLA, January 13-18, 1991, pp. J13-J18.\nRopelewski, C. F. and A. G. Barnston, \"Why predict ENSO?,\nProceedings of the 15th Annual Climate Diagnostics\nWorkshop, Asheville, NC, October 29-November 2, 1990, pp.\n26-29.\nRopelewski, C. F. and M. S. Halpert, \"The Southern Oscillation\nand Northern Hemisphere temperature variability, \"Greenhouse\nGas-Induced Climatic Change: A Critical Appraisal of\nSimulations and Observations, (M. E. Schlesinger, Editor),\nElsevier Science Publishers , Amsterdam, 1991, pp. 369-376.\nSalstein, D. A. and D. M. Kann, \"The Sub-Bureau for Atmospheric\nAngular Momentum at CAC: Earth rotation-related data from\nMeteorological Centers,\" Proceedings of the 15th Climate\nDiagnostics Workshop, Asheville, NC, October 29-November 2,\n1990, pp. 231-236\nShea, D. J. , K. E. Trenberth and R. W. Reynolds: \"A global\nmonthly sea surface temperature climatology,\" NCAR\nTechnical Note, NCAR/TN-345 STR, Boulder, CO, 1991, 167 pp.\n118","Smith, T. M. , \"Interannual changes in the tropical Pacific Ocean\nfrom 1985-1989: Heat storage variability, : Proceedings of\nthe 15th Climate Diagnostics Workshop, Asheville,\nNC,\nOctober 29-November 2, 1990, pp. 60-64.\nvan den Dool, H. M. and C. J. Schuurmans, \"Uitzonderlyk warm,\"\nZenit, June 1991, pp. 214-216.\nvan den Dool, H. M. , J. Feng and T. Murphree, \"Dynamic\ncalculation of teleconnections, \" Proceedings of the 15th\nClimate Diagnostics Workshop, Asheville, NC, October 29-\nNovember 2, 1990, pp. 520-527.\nWang, X-L. and E. M. Rasmusson, \"The dominant planetary-scale\nmodes of ENSO cycle variability, \" Proceedings of the 15th\nAnnual Climate Diagnostics Workshop, Asheville, NC, October\n29-November 2, 1990, pp. 76-80.\n119","Presentations at Formal Scientific Meetings*\n7.3\nBell, G.D., \"Mid - tropospheric cutoff cyclogenesis,\" presented\nat the AMS/First International Winter Storms Conference,\nNew Orleans, LA, January 14-18, 1991.\nBell, G. D. \"Shear and curvature potential vorticity\ninterchanges during cutoff cyclone formation,\" presented at\nthe AMS/First International Winter Storms Conference, New\nOrleans, LA, January 14-18, 1991.\nBermowitz, R. J. \"Climate services, development and research\nactivities at the NOAA/NWS Climate Centers, presented at\nthe Southern Data Management Workshop, Atlanta, GA, June\n10-13, 1991.\nGelman, M. E. , \"Detection of stratospheric change,\" presented at\nthe TOVS Pathfinder Science Working Group Meeting,\nUniversity of Maryland, College Park MD, June 19, 1991.\nHeddinghaus, T. R. and D. M. Le Comte, \"Over a century of\nmonitoring and disseminating agricultural weather data: The\nWeekly Weather and Crop Bulletin,\" presented at the\nNational Weather Association Fourteenth Annual Meeting, New\nCarrollton, MD, October 15-19, 1990.\nHou, Y. K. A. Campana, K. Mitchell, S. K. Yang and L. L. Stowe,\n\"Evaluation an experimental satellite-derived cloud data\nset for real-time use,\" presented at the Workshop on\nAerosol-Cloud-Climate Interactions IAMAP/IUGG Vienna,\nAustria, August 11-24, 1991.\nJanowiak, J. E. \"Comparison between satellite derived rainfall\nestimates and model precipitation forecasts in the\nTropics, presented at the NMC/NCAR Reanalysis Workshop,\nCamp Springs, MD, April 26, 1991.\nJanowiak, J. E. \"Status of GPCP activities at CAC,\" \" presented\nto the Working Group on Data Management of the Global\nPrecipitation Climatology Project, Laurel, MD, May 20,\n1991.\nJanowiak, J. E. , \"Performance of GPI rainfall estimates during\nthe First Algorithm Intercomparison Project,\" presented at\nthe GPCP Algorithm Intercomparison Workshop, Laurel, MD,\nMay 22, 1991.\n* There were 37 additional presentations that were either\npublished in a Proceedings or Preprint Volume of a formal\nscientific meeting, but are only listed in Section 7.2.\n120","Janowiak, J.E., P. A. Arkin, and T. H. Lee, \" A comparison of\nsatellite-derived rainfall estimates with ground-based\nobservations over Japan,\" presented at the International\nUnion of Geophysical Scientists, Vienna, Austria, August\n16, 1991.\nJanowiak, J. E. , T. H. Lee and P. A. Arkin, \"A comparison\nbetween satellite-derived rainfall and ground observations,\nPart I: IR-based satellite estimates, presented at the\nAGU Spring Meeting, Session on Remote Sensing of\nPrecipitation, Baltimore, MD, May 29, 1991.\nKousky, V. E. \"Update on the Southern Oscillation,\" presented\nat the Climate Systems Monitoring Meeting, Helsinki,\nFinland, August 26-30, 1991.\nLaver, J. D. and L. Thomas, \"Accessibility of NOAA'S current\nclimate data and products in the era of enhanced climate\nservices, presented at the AMS/ Seventh IIPS Conference,\nNew Orleans, LA, January 16, 1991.\nLee, T. H. J. E. Janowiak and P. A. Arkin, \"A comparison\nbetween satellite-derived rainfall and ground observations,\nPart II: Microwave Based Satellite Estimates,\" presented\nat the AGU Spring Meeting, Session on Remote Sensing of\nPrecipitation, Baltimore, MD, May 29, 1991.\nLeetmaa, A., \"Model - based analyses for the Pacific Ocean, \"\n(Invited Talk), presented at the Annual AGU Meeting, San\nFrancisco, CA, December 5, 1990.\nLeetmaa, A. , \"Progress in coupled model studies at NMC, \"\npresented at the Epocs Council Meeting, Miami, FL, January\n21-23, 1991.\nLeetmaa, A. , \"Estimation of the net surface heat flux in the\nPacific,\" presented at the Epocs Council Meeting, Miami,\nFL, January 21-23, 1991.\nLehman, R. E. , \"Accurate climatological tools for projecting\nmonthly gas sales and monitoring annual conservation\ntrends, presented at the Conference on PC Applications in\nthe Gas Industry, Chicago, IL, May 6-8, 1991.\nLehman, R. E. , \"New CAC Products for Climate Impact Evaluation, \"\npresented at the Workshop on Climate Predictability and\nGlobal Change in the Southeast U. S., Univ. of Alabama,\nHuntsville, Al, June 3-4, 1991.\nLivezey, R. E. \"Seasonal predictability and prediction in the\nextratropics,\" presented at the WMO Training Workshop on\nDiagnosis and Prediction of Monthly and Seasonal\nAtmospheric Variations, Nanjing, China, October 15-19,\n1990.\n121","Livezey, R. E. , \"Status and recommendations for long-range\nforecasting,\" presented at the WMO Workshop on Diagnosis\nand Prediction of Monthly and Seasonal Atmospheric\nVariations, Nanjing, China, October 15-19, 1990.\nLivezey, R. E. , \"Skill characteristics of U.S. long-range\nforecasts,\" presented at the ICS/ICTP/WMO International\nTechnical Conference on Long-Range Weather Prediction\nResearch, Trieste, Italy, April 11, 1991.\nMo, K. C., \"Diagnostics and monitoring of re-analysis climate\nstatistics,\" presented at the NMC/NCAR Re-Analysis\nWorkshop, Camp Springs, MD, April 25-26, 1991.\nNagatani, R. M., \"Availability and access of NMC support data\nfor UARS, \" presented at the UARS Data Systems Working Group\n(DSWG) Meeting, Port Jefferson, NY, February 11, 1991.\nNagatani, R. M., \"Quality of stratospheric datasets at NMC,\"\npresented at the Models and Measurements Committee Meeting\nof NASA's High Speed Research Project (HSRP), Washington,\nD.C., March 13, 1991.\nNagatani, R. M., A. J. Miller, G. C. Tiao, X. F. Niu, G. C.\nReinsel, D. Wuebbles, and K. Grant: \"Observed lower\nstratospheric ozone and temperature Trends from radiosondes\nand ozonesondes compared with model trends,\" presented at\nthe IUGG/IAMAP Meeting, Session M10.4, Modelling and\nObservations of Ozone and Other Minor Constituents, Vienna,\nAustria, August 11-24,1991.\nNagatani, R. M., D. A. Salstein, D. M. Kann, and A. J. Miller,\n\"Report of the Sub-Bureau for Atmospheric Angular\nMomentum, IUGG/IAG Special Study Group 5-98 Meeting,\nVienna, Austria, August 15, 1991.\nO'Lenic, E. A., \"Creating a long-range forecast, presented at\nthe Workshop on Climate Predictability and Global Change:\nIssues in the Southeast, Huntsville, AL, June 3-4, 1991.\nRodenhuis, D. R. \"Near real-time climate assessment,\" presented\nat the Annual Meeting of the American Association for State\nClimatologists, Fairbanks, AK, August 5-9, 1991.\nRodenhuis, D. R. \"Status of ASOS, presented at the Annual\nMeeting of the American Association for State Climatolo-\ngists, Fairbanks, AK, August 5-9, 1991.\nRodenhuis, D. R. \"The RCC Program,\" presented at the Annual\nMeeting of the American Association for State Climatolo-\ngists, Fairbanks, AK, August 5-9, 1991.\nRodenhuis, D. R. \"Current climate assessment, \" presented at the\nSpecial Workshop on Climate Monitoring, State Hydrological\nInstitute, Leningrad, USSR, September 16, 1991.\n122","Ropelewski, C. F. , \"Real-time monitoring and prediction of ENSO\nand its impacts,\" presented at the WMO Technical Conference\non El Niño and its Climatic Implications, Montevideo,\nUruguay, December 4-9, 1990.\nRopelewski, C. F. \"The current state of the Southern\nOscillation,\" presented at the TOGA Panel Meeting, Miami,\nFL, January 23, 1991.\nRopelewski, C. F. \"The state of the Southern Oscillation,\"\npresented at the Eight Annual Pacific Climate Workshop,\nAsilomar, CA, March 10, 1991.\nRopelewski, C. F., \"The use of AVHRR derived vegetation index\nfor climate monitoring,\" presented at the Eight Annual\nPacific Climate Workshop, Asilomar, CA, March 11, 1991.\nRopelewski, C. F. \"Data requirements for real-time climate\nmonitoring, presented at the NOAA Workshop on the Quality\nand Continuity of Environmental Data, Silver Spring, MD,\nApril 11-12, 1991.\nRopelewski, C. F. \"The current state of the Southern\nOscillation,\" presented at the TOGA Advisory Panel Meeting,\nWashington, D.C., April 29, 1991.\nRopelewski, C. F. \"Is the climate changing?, presented at the\nWorkshop on Climate Predictability in the Southeast U.S., ,\nUniv. of Alabama, Huntsville, AL, June 3-4, 1991.\nRopelewski, C. F. \"The Southern Oscillation and climate\nvariability in the Southeast,\" presented at the Workshop\non Climate Predictability in the Southeast U.S., Univ. of\nAlabama, Huntsville, AL, June 3-4, 1991.\nRopelewski, C. F. , \"Sampling uncertainties in estimates of\nglobal temperature, presented at the Global Climate\nPerspectives Workshop, Boulder, CO, June 25-27, 1991.\nRopelewski, C. F. \"Global drought monitoring using the\nprecipitation anomaly classification (PAC),\" presented at\nthe Global Climate Perspectives Workshop, Boulder, CO, June\n25-27, 1991.\nRopelewski, C. F. , \"ENSO and biennial variability,\" presented at\nthe IUGG/IAPSO Symposium on Low-Latitude Ocean-Atmospherio\nCoupling, Vienna, Austria, August 12-17, 1991.\nvan den Dool, H. M. \"Introduction to CAC and predictability,\"\npresented at the Workshop on Climate Predictability in the\nSoutheast U.S., Univ. of Alabama, Huntsville, AL, June 3-4,\n1991.\n123","Yang, S. K. , \"Cloud parameterization in the NMC's Medium Range\nForecast Model, \" presented at the Fourth CERES Science Team\nMeeting, NASA Langley Research Center, Hampton, VA,\nNovember 14-15, 1990.\nYang, S. K. , \"Evaluation of the new ERBE S-4G product, \"\npresented at the 28th ERBE Science Team Meeting, Scripps\nInstitution of Oceanography, La Jolla, CA, February 28,\n1991.\nYang, S. K. , \"NMC T80 NWP model runs for April 1989 Surface\nRadiation Budget Experiment, \" presented at the Fifth CERES\nScience Team Meeting, Hampton, VA, April 30 - May 2, 1991.\nYang, S. K. , S. S. Zhou and L. M. McMillin, \"Evaluation of the\nNOAA/NESDIS TOVS cloud product, \" presented at the Workshop\non Aerosol-Cloud-Climate Interactions IAMAP/IUGG, Vienna,\nAustria, August 11-24, 1991.\nZhou, S. S. , L. M. McMillin and S. K. Yang, \"An improved cloud\nretrieveal algorithm using HIRS2/MSU radiance measure- -\nments, \" presented at the 6th International TOVS Study\nConference, Airlie, VA, May 1-6, 1991.\n124","7.4\nSeminars And Briefings\nBarnston, A. G., \"Principal Components Analysis as a data\nanalysis tool\" , presented at the NASA/Langley Research\nCenter, Hampton, VA, September 11, 1991.\nBell, G. D. \"Mid-tropospheric cutoff cyclogenesis,\" presented\nat a CAC-Sponsored Seminar, Camp Springs, MD, March 14,\n1991.\nBell, G. D. \"Potential vorticity evolution during cutoff\ncyclone formation.\" presented at National Meteorological\nCenter Seminar, Camp Springs, MD, April 8, 1991.\nBell, G. D. \"Monthly and seasonal (MAM 1991) climate reviews, \"\npresented at NMC/Climate Analysis Center Briefings, Camp\nSprings, MD, April 9, May 7, and June 11, 1991.\nBell, G.D., \"Mid-Troposheric Cutoff Cyclogenesis, presented at\na NMC Seminar, Camp Springs, MD, May 15, 1991\nChelliah, M. \"Examination of co-variability in tropical\nconvection and global circulation,\" presented at a CAC-\nSponsored Seminar, Camp Springs, MD, November 15, 1990.\nChelliah, M. , \"Monthly and seasonal (DJF 1990-91) climate\nreviews, \" presented at NMC/Climate Analysis Center,\nBriefings, Camp Springs, MD, January 8, February 12, and\nMarch 12, 1991.\nChen, W-Y. \"Establishment, maintenance, and demise of an\nAtlantic block,\" presented at a CAC-Sponsored Seminar,\nCamp Springs, MD, October 2, 1990.\nChen, W-Y., \"Rapid establishment and demise of a 30-day long\nAtlantic blocking episode, presented at NASA/GSFC,\nGreenbelt, MD, November 29, 1990.\nChen, W-Y., \"Diagnosis of regime transition mechanism of\nblocking flow,\" presented at a CAC-Sponsored Seminar, Camp\nSprings, MD, March 7, 1991.\nGelman, M. E. \"Status of FMH for rawinsonde observations,\"\npresented before Committee for Basic Services, Working\nGroup for Upper Air Observations, OFCM, Rockville, MD,\nJanuary 23, 1991.\nHalpert, M. S. , \"Monthly and seasonal (JJA 1991) climate\nreviews, \" presented at NMC/Climate Analysis Center,\nBriefings, Camp Springs, MD, July 9, August 8, and\nSeptember 10, 1991.\n125","Huang, J. , \"Small ice cap instability in an energy balance\nmodel, presented at a CAC-Sponsored Seminar, Camp Springs,\nMD, October 18, 1990.\nJanowiak, J. E. , Comparisons between GPCP rainfall estimates and\nNMC model precipitation forecasts, presented at a NMC/\nDevelopment Division Weekly Forum, Camp Springs, MD,\nNovember 15, 1990.\nJanowiak, J. E. / \"Results of the comparison of IR-based rainfall\nestimates from the NOAA-10 satellite with corresponding\nestimates from various algorithms applied to SSM/I data, \"\nNESDIS briefing, Camp Springs, MD, November 17, 1990\nJanowiak, J. E., \"Status of GPCP activities at CAC,\" presented\nat the NESDIS Research and Development Council Meeting,\nCamp Springs, MD, December 12, 1990\n.\nJanowiak, J. E. \"Tropical rainfall: Satellite estimate vs. MRF\nand ECMWF model forecasts, \" presented at a CAC-Sponsored\nSeminar, Camp Springs, MD, February 14, 1991.\nKousky, V. E. \"Real-time monitoring at the CAC,\" presented at\nthe Finnish Meteorological Institute, Helsinki, Finland\nAugust 23, 1991.\nLaver, J. D. \"The CAC/RCC program management plan,\" presented at\nthe RCC Leader's Meeting, New Orleans, LA, January 15,\n1991.\nLaver, J. D. \"Update on Regional Climate Centers management and\nactivities,\" presented at the Climate Services Management\nCouncil Meeting, Asheville, NC, March 8, 1991.\nLeetmaa, A., \"Air-sea interaction in the tropical Pacific,\"\npresented at a CAC-Sponsored Seminar, Camp Springs, MD,\nDecember 13, 1990.\nLeetmaa, A., \"Coupled model studies at NMC,\" presented at the\nClimate Services Troika Meeting, Asheville, NC, March 8,\n1991.\nLivezey, R.E., \"Perspective on DERF: State of the art and\nrecommendations for future direction, presented at a CAC-\nSponsored Seminar, Camp Springs, MD, November 8, 1990.\nLivezey, R.E., \"Some long-range forecasting activity at USSR\nhydrometeorology center: A joint experiment in seasonal\nempirical prediction, presented at a CAC-Sponsored\nSeminar, Camp Springs, MD, December 18, 1990.\nLivezey, R. E., \"Some skill characteristics of CAC long-range\nforecasts,\" presented at the University of Maryland,\nCollege Park, MD, March 14, 1991.\n126","Long, C. S. \"Stratospheric assessment of spectral statistical\ninterpolation (SSI) analysis, briefings for Director/NMC,\nCamp Springs, MD, April 4 and 24, 1991.\nMiller, A. J., \"The Stratospheric Monitoring Program,\" presented\nat the U.S. Naval Academy, Annapolis, MD, March 12, 1991.\nMo, K. \"Monthly and seasonal (SON 1990) climate reviews, \"\npresented at NMC/Climate Analysis Center Briefings, Camp\nSprings, MD, October 7 , November 9, and December 11, 1990.\nMo, K., \"The 200-mb vorticity budget during the 1986-89 ENSO\ncycle as revealed by NMC analyses,\" presented at a CAC-\nSponsored Seminar, Camp Springs, MD, November 29, 1990.\nMo, K., \"A striking WPO event during November 1990,\" presented\nat UCLA, Los Angeles, CA, January 24, 1991.\nMo, K. \"The impact of sea-surface temperature on the monthly\nforecasts, presented at UCLA, Los Angeles, CA, February\n8, 1991.\nMo, K. \"Real-time climate monitoring,\" presented at San Jose\nState Univ., San Jose, CA, Feb. 20, 1991; and at the\nUniversity of Utah, Salt Lake City, UT, March 5, 1991.\nMurphy, A. H. \"On the theory of forecast verification,\"\npresented at a CAC-Sponsored Seminar, Camp Springs, MD,\nMarch 28, 1991.\nReynolds, R. W., \"The advantage of the Optimum Interpolation\nanalysis in SST\", presented at a CAFTI Meeting, Camp\nSprings, MD, January 30, 1991.\nReynolds, R. W., \"A new global high-resolution SST analysis,\npresented at a CAC-Sponsored Seminar, Camp Springs, MD,\nApril 4, 1991.\nRodenhuis, D. R., \"Climate apocalypse,\" presented at the Federal\nExecutive Institute, Charlottesville, VA, June 12, 1991.\nRopelewski, C. F., \"Climate assessment: A review of the decade,\n1981-1990,\" presented at the Climate Services Management\nCouncil Meeting, Asheville, NC, March 8, 1991.\nRopelewski, C. F. \"The decade of the 1980's: Variability and\ntrends, presented at the Naval Postgraduate School,\nMonterey, CA, March 14, 1991.\nRopelewski, C. F. \"An overview of the Climate Analysis Center,\"\npresented at the NMC Seminar for NWS Support Personnel,\nCamp Springs, MD, June 13, 1991.\nSchultz, P. \"NCAR-GCM hydrology: HOW bad is it?,\" presented at\na CAC-Sponsored Seminar, Camp Springs, MD, May 23, 1991.\n127","van den Dool, H.M., \"Weather update: Assessment of upcoming\nwinter,\" presented at the Dept. of Energy and Petroleum\nIndustry Research Foundation, Washington, D.C., October 2,\n1990.\nvan den Dool, H.M., \"Medium and long-range forecasting at CAC, \"\npresented at von Humboldt University, Berlin, FRG, January\n3, 1991.\nvan den Dool, H.M., \"Low-frequency waves and traveling storm\ntracks, \" presented at the Royal Netherland Meteorological\nInstitute, de Bilt, Netherlands, January 8, 1991.\nvan den Dool, H. M. , \"Ten year integration of the NMC model, \"\npresented at the Climate Services Troika Meeting,\nAsheville, NC, March 8, 1991.\nvan den Dool, H. M. , \"A 10-year run with the MRF model \"\npresented at: AMIP, Berkeley, CA, April 5, 1991; Naval\nPost Graduate School, Monterrey, CA, April 9, 1991; DERF\nWorkshop, Camp Springs, MD, April 24, 1991; and at a NMC\nSeminar, Camp Springs, MD, May 20, 1991.\n128","7.5\nGrant Program\nCAC continued its support to universities and private\ninstitutions to undertake diagnostic studies and research that\ncontribute directly to the improvement of CAC's operational\nmonitoring and prediction programs. The results from each\nproject are reported in the literature and in final reports to\nEach institution, title of study and principal\nCAC.\ninvestigator is listed below.\nStart\nPrincipal\nDate\nInstitution\nTitle\nInvestigator\nMay 1991\nUniversity of\nCooperative Institute\nEllingson\n(Renewal)\nMaryland\nfor Climate Studies\nAug. 1991\nUniversity of\nStatistical Analysis of\nTiao\n(Renewal)\nChicago\nStratospheric Temperature\nData for Trend Analysis\nAug. 1991\nUniversity of\nAn Investigation on the\nMass\n(New)\nWashington\nUse of CD-ROM for Climate\nApplication and Research\nAug. 1991\nScientific Program\nUCAR\nAnthes\n(Renewal)\nREGIONAL CLIMATE CENTERS PROGRAM\nStart\nPrincipal\nDate\nInstitution\nTitle\nInvestigator\nMar. 1991\nUniversity of\nWestern RCC\nWarburton\nNevada\nMay 1991\nUniversity of\nHigh Plains RCC\nHubbard\nNebraska-Lincoln\nMay 1991\nSo. Carolina Water\nSoutheastern RCC\nSmith\nResources Commis.\nJune 1991\nUniversity of\nMidwestern RCC\nKunkel\nIllinois\nJune 1991\nCornell Univ.\nNortheastern RCC\nKnapp\nAug. 1991\nLouisiana St.\nSouthern RCC\nMuller\nUniversity\n129","7.6 CAC - Sponsored Seminar Series\nSpeaker: Dr. Wilbur Chen\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Eastablishment, Maintenance, and Demise of an\nAtlantic Block\"\nDate:\nOctober 2, 1991\nSpeaker: Dr. Chung-Hsiung Sui\nLaboratory For Atmospheres\nNASA/GSFC\nGreenbelt, MD\nTitle:\n\"Observed and Simulated Multiscale Phenomena in\nthe Tropical Western Pacific\"\nOctober 4, 1990\nSpeaker: Dr. Larry L. Stowe\nNOAA/NESDIS\nOffice of Research & Applications\nCamp Springs, MD\nTitle:\n\"The Development of Cloud and Aerosol\nClimatologies at NOAA/NESDIS\"\nDate:\nOctober 11, 1990\nSpeaker:\nMs. Jin Huang\nDepartment of Atmospheric Sciences\nUniversity of Illinois\nChampaign - Urbana, IL\nTitle:\n\"Small Ice Cap Instability in an Energy Balance Model\"\nDate:\nOctober 18, 1990\nSpeaker:\nProf. Ferd Baer\nDepartment of Meteorology\nUniversity of Maryland\nCollege Park, MD\nTitle:\n\"Optional Vertical Levels and Three-Dimensional\nTruncation In Models\"\nDate:\nOctober 23, 1990\n130","Speaker:\nDr. Robert E. Livezey\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Perspectives on Dynamic Extended and Long-Range\nForecasting: State of the Art and Recommendations\nfor Future Directions\"\nDate:\nNovember 8, 1990\nSpeaker:\nDr. Stephen J. Colucci\nDepartment of Soil, Crops, and Atmosphere\nCornell University\nIthaca, NY\nTitle:\n\"Planetary Scale Climatology of Explosive\nCyclogenesis and Blocking: Implications for\nLong-Range Forecasting\"\nDate:\nNovember 13, 1990\nSpeaker: Dr. Muthuvel Chelliah\nRDS, Corporation\nContract Scientist, NMC/CAC\nCamp Springs, MD\nTitle:\n\"Examination of Co-Variability In Tropical\nConvection and Global Circulation\"\nDate:\nNovember 15, 1990\nSpeaker:\nDr. Kingtse Mo\nDr. Eugene Rasmusson\nNOAA/National Weather Service\nDept. of Meteorology\nNMC/Climate Analysis Center\nUniversity of Maryland\nCamp Springs, MD\nCollege Park, MD\nTitle:\n\"The 200 MB Vorticity Budget during the 1986-89\nENSO Cycle As Revealed by NMC Analyses\"\nDate:\nNovember 29, 1990\nSpeaker:\nDr. Siegfried Schubert\nLaboratory For Atmospheres\nNASA/GSFC\nGreenbelt, MD\nTitle:\n\"Persistence And Predictability\"\nDate:\nDecember 6, 1990\n131","Speaker: Dr. Stanley Grotch\nLawrence Livermore National Laboratory\nLivermore, CA\nTitle:\n\"Zonal Statistics: GCM Intercomparisons\"\nDate:\nDecember 10, 1990\nSpeaker:\nDr. Ants Leetmaa\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Air-Sea Interaction in the Tropical Pacific\"\nDate:\nDecember 13, 1990\nSpeaker:\nDr. Robert E. Livezey\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Some Long-Range Forecasting Activity at the\nUSSR Hydrometeorological Center: A Joint\nExperiment In Seasonal Empirical Prediction\"\nDate:\nDecember 18, 1990\nSpeaker:\nDr. Zoltan Toth\nNRC- Post Doctoral Program\nNWS/National Meteorological Center\nCamp Springs, MD\nTitle:\n\"Global And Local Characteristics of The Extra-\nTropical NH WinterTime Circulation Phase Space\"\nDate:\nJanuary 24, 1991\nSpeaker:\nDr. G. Garik Gutman\nNOAA/NESDIS\nSatellite Research Laboratory\nCamp Springs, MD\nTitle:\n\"Climatology of Land Surfaces from NOAA\nAVHRR Observations\"\nDate:\nJanuary 31, 1991\n132","Speaker:\nDr. Ilya Polyak\nInvited Speaker\nTitle:\n\"Multivariate Stationary and Non-Stationary\nStochastic Models and their Applications to\nClimatology\"\nDate:\nFebruary 8, 1991\nSpeaker:\nJohn E. Janowiak\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Tropical Rainfall: Satellite Estimate vs. MRF\nand ECMWF Model Forecasts\"\nDate:\nFebruary 14, 1991\nSpeaker: Dr. G.V. Gruza & Dr. E.Y. Rankova\nInstitute For Global Climate And Ecology\nMoscow, USSR\nTitle:\n\"Monitoring And Probabilistics Forecasts of Short-\nTerm Climate Fluctuations\"\nDate:\nFebruary 21, 1991\nDr. Wilbur Chen\nSpeaker:\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Diagnosis of Regime Transition Mechanism of\nBlocking Flow\"\nDate:\nMarch 7, 1991\nSpeaker:\nDr. Gerald Bell\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"Mid-Tropospheric Cutoff Cyclogenesis\"\nDate:\nMarch 14, 1991\n133","Speaker:\nDr. Chi-Dong Zhang\nDept. of Meteorology\nPenn State University\nState College, PA\nTitle:\n\"Climatological Relationship between SST and OLR\nover the Tropical Pacific Ocean\"\nDate:\nMarch 21, 1991\nSpeaker:\nProf. Allan H. Murphy\nOregon State University\nUCAR Visiting Scientist, NMC/CAC\nCamp Springs, MD\nTitle:\n\"On the \"Theory\" of Forecast Verification\"\nDate:\nMarch 28, 1991\nSpeaker: Dr. Richard W. Reynolds\nNOAA/National Weather Service\nNMC/Climate Analysis Center\nCamp Springs, MD\nTitle:\n\"New Global High-Resolution SST Analysis\"\nDate:\nApril 4, 1991\nSpeaker:\nDr. K. M. Lau\nLaboratory For Atmospheres\nNASA/GSFC\nGreenbelt, MD\nTitle:\n\"Dynamics of Atmospheric Teleconnections During\nNorthern Summer\"\nDate:\nApril 18, 1991\nSpeaker: Dr. James Carton\nDepartment of Meteorology\nUniversity of Maryland\nCollege Park, MD\nTitle:\n\"Seasonal Salinity and Fresh Water Balances in the\nTropical Atlantic Ocean\"\nDate:\nMay 2, 1991\n134","Speaker:\nDr. Majib Latif\nMax-Planck Institute For Meteorology\nHamburg, FRG\nTitle:\n\"Predictability of Enso\"\nDate:\nMay 21, 1991\nSpeaker:\nMr. Peter Schultz\nRDS, Corp.\nContract Scientist, NMC/CAC\nCamp Springs, MD\nTitle:\n\"NCAR GCM Hydrology: How Bad Is It?\"\nDate:\nMay 23, 1991\nSpeaker:\nDr. Glenn White\nNMC/Development Division\nNOAA/National Weather Service\nCamp Springs, MD\nTitle:\n\"Systematic Errors in the MRF and Other Models\"\nDate:\nMay 30, 1991\nSpeaker:\nDr . Daniel S. Wilks\nDept. of Meteorology\nCornell University\nIthaca, NY\nTitle:\n\"Estimating The Monthly And Seasonal Precipitation\nDistributions Using the 30-Day and 90-Day Outlooks\"\nDate:\nJune 20, 1991\n135","7.7 Visitors\nNAME\nAFFILIATION\nDATE\nDr. C-H. Sui\nLaboratory for Atmospheres\nOct. 2, 1990\nNASA/GSFC\nGreenbelt, MD\nDr. D. Webster\nActg. Director General\nOct. 10, 1990\nDr. G. Schaefer\nActg. Chief, Hydromteor.\nResearch Division\nJ. Sandilands\nClimate Services\nR. Morris\nData Management\nCanadian Climate Center\nDownsview, Canada\nDr. M. Takeuchi\nDept. of Civil &\nOct. 21, 1990\nEnvironmental Engineering,\nYamanashi University\nKofu, Japan\nProf. F. Baer\nDept. of Meteorology\nOct. 23, 1990\nUniv. of Maryland\nCollege Park, MD\nProf. A. H. Murphy\nVisiting Scientist, UCAR\nNov. 1990 -\nOregon St. University\nNov. 1991\nCorvallis, OR\nP. Csapo\nHungarian Meteorological\nNov. 7, 1990\nService\nBudapest, Hungary\nDr. S. Colucci\nDept. of Soil, Crops\nNov. 13, 1990\nand Atmosphere\nCornell University\nIthaca, NY\nDr. K. Vinnikov\nState Hydrological Inst.\nNov. 19, 1990\nLeningrad, USSR\nJ. Canby\nNational Geographic\nNov. 20-29,\nWashington, D.C.\n1990\nDr. K. Katsoras\nUniversity of Washington\nDec. 4, 1990\nSeattle, WA\nDr. K. Weikman\nNOAA/ERL\nDec. 5, 1990\nDr. M. Hoerling\nBoulder, CO\nDr. A. Shabbar\nCanadian Climate Center\nDec. 5, 1990\nDownsview, Canada\n136","Dr. S. Schubert\nLaboratory for Atmospheres\nDec. 6, 1990\nNASA/GSFC\nGreenbelt, MD\nDr. S. L. Grotch\nLawrence Livermore\nDec. 10, 1990\nNational Laboratory\nLivermore, CA\nDr. V. Gowariker\nSecretary of Science\nDec. 12, 1990\nand Technology\nNew Delhi, India\nDr. J. P. Gupta\nCounsellor (Science)\nDec. 12, 1990\nEmbassy of India\nWashington, D.C.\nDr. P. R. Pisharoty\nIMO Prize Winner\nDec. 12, 1990\nNew Delhi, India\nB. Gezaw\nDirector, Ethiopian\nDec. 12, 1990\nEarly Warning System\nAdis Abbaba, Ethiopa\nDr. M. Mak\nUniv. of Illinois\nDec. 12, 1990\nChampaign-Urbana IL\nJ. Christy\nUniv. of Alabama\nDec. 13, 1990\nHuntsville, AL\nJ. Purvis\nSoutheast Regional\nDec. 17, 1990\nD. Smith\nClimate Center\nColumbia, SC\nProf. G. V. Gruza\nInst. for Global Climate\nJan. 8-Mar. 5,\nProf. E. Ran'kova\nand Ecology\n1991\nMoscow, USSR\nDr. M. Kayano\nINPE\nJan.-May 1991\nSao Paulo, Brazil\nProf. J.M. Wallace\nUniv. of Washington\nJan 9, 1991\nSeattle, WA\nF. Zwiers\nCanadian Climate Centre\nMar. 1, 1991\nDownsview, Canada\nProf. J. Young\nUniv. of Wisconsin\nMar. 11, 1991\nMadison, WI\nN. Hoffman\nMIC, WSFO\nMar. 11, 1991\nSan Francisco, CA\nA. Haffer\nMIC, WSFO\nMar. 11, 1991\nPhoenix, AZ\n137","Dr. C-D. Zhang\nDept. of Meteorology\nMar. 21, 1991\nPenn St. University\nState College, PA\nDr. N. Gershon\nMitre, Space Systems Div.\nMar. 21, 1991\nMcLean, VA\nM. Roos\nCal. Dept. of Water Res.\nMar. 25, 1991\nSacremento, CA\nDr. I. Burton\nDirector, Natural & Human\nApr. 9, 1991\nSciences and Integration\nAtmos. Envir. Service\nOttawa, Ontario, Canada\nDr. K-M. Lau\nLaboratory for Atmospheres\nApr. 18, 1991\nNASA/GSFC\nGreenbelt, MD\nDr. S. L. Grotch\nLawrence Livermore\nApr. 24, 1991\nNational Laboratory\nLivermore, CA\nDr. A. Oort\nNOAA/GFDL\nApr. 24, 1991\nPrinceton, NJ\nDr. J. Lanzante\nNOAA/GFDL\nApr. 26, 1991\nPrinceton, NJ\nDr. D. Salstein\nAER Inc.\nApr. 26, 1991\nCambridge, MA\nL. Mooney\nMIC, WSFO\nApr. 29, 1991\nDenver, CO\nC. Liles\nMIC, WSFO\nApr. 29, 1991\nAlbuquerque, NM\nDr. . P. D. Joseph\nNOAA/ERL/CIRES\nApr. 30, 1991\nBoulder, CO\nDr. J. Carton\nDept. of Meteorology\nMay 2, 1991\nUniv. of Maryland\nCollege Park, MD\nD. Salmon\nKnight-Ridder - Global\nMay 8, 1991\nFinancial News\nKansas City, KS\nP. Roebber\nMcGill University\nMay 20, 1991\nMontreal, Canada\nDr. M. Latif\nMax-Planck Institute\nMay 21, 1991\nfor Meteorology\nHamburg, FRG\n138","Dr. S. Mullen\nUniversity of Arizona\nMay 23, 1991\nTuscon, AZ\nDr. R. Muller\nSouthern Regional\nMay 24, 1991\nClimate Center\nNew Orleans, LA\nD. Smith\nSoutheastern Regional\nMay 24, 1991\nClimate Center\nColumbia, SC\nIndian Inst. of Science\nDr. S. Gadgil\nJune 4, 1991\nBangalore, India\nWorld Climate Data\nJune 8, 1991\nDr. M. Crowe\nProgramme, WMO\nGeneva, Switzerland\nDr. D. S. Wilks\nCornell University\nJune 20, 1991\nIthaca, NY\nDr. J. Nogues-Paegle\nUniversity of Utah\nJune 24-27,\nSalt Lake City\n1991\nUCAR, Visiting Scientist\nAug. 1 - Oct.\nDr. A. Johannsson\nUniv. of Stockholm\n31, 1991\nStockholm, Sweden\nC.E.O., Research Data\nSep. 23, 1991\nDr. K. S. Vasan\nSystems Corporation\nGreenbelt, MD\n139"]}