NOCN03 CWAO 231535 GENOT TLTP. NO. 002 IMPROVEMENT TO THE GLOBAL, REGIONAL AND ENSEMBLE ASSIMILATION SYSTEMS OF THE CANADIAN METEOROLOGICAL CENTRE STARTING ON MAY 28 AT 12 UTC, THE CANADIAN METEOROLOGICAL CENTRE'S GLOBAL, REGIONAL AND ENSEMBLE ASSIMILATION SYSTEMS WILL HAVE THE FOLLOWING CHANGES. OVERVIEW OF CHANGES THE CHANGES WILL BE PORTED ON THE GLOBAL 4D-VAR VARIATIONAL ASSIMILATION SYSTEM, THE REGIONAL 3-D VAR ASSIMILATION SYSTEM AND THE ENSEMBLE KALMAN FILTER FOR THE ENSEMBLE PREDICTION SYSTEM. FIRST, RADIANCE DATA FROM 87 INFRA-RED AIRS CHANNELS FROM THE AQUA SATELLITE AND 7 MICROWAVE CHANNELS FROM THE SSM/I OF THE F-13 AND F-14 SATELLITES WILL BE ASSIMILATED BY THE GLOBAL AND REGIONAL ASSIMILATION SYSTEMS ONLY. FURTHER MORE OCEAN SURFACE WINDS FROM QUICKSCAT'S SEAWINDS SCATEROMETER, GOES SATELLITE WINDS FROM THE 3.9 MICRONS CHANNEL AND SUPPLEMENTAL DATA FROM AMSUA, AMSUB OR MHS NEAR SWATH EDGES FROM THE NOAA AND AQUA SATELLITES WILL ALSO BE ASSIMILATED IN THE GLOBAL, REGIONAL AND ALSO ENSEMBLE FORECAST SYSTEM. ALSO DYNAMICAL BIAS CORRECTION OF SATELLITE RADIANCES WILL BE ACCOMPANYING THIS NEW PACKAGE INCLUDING THE USAGE OF VERSION 8 OF THE FAST RADIATIVE TRANSFER MODEL RTTOV AND FOR THE GLOBAL AND REGIONAL MODELS THE USE OF A NEW VERTICAL INTERPOLATOR FROM THE RTTOV LEVELS TO THE GEM LEVELS FOR THE ASSIMILATION OF RADIANCES. FINALLY AMSUA CHANNEL 3 DATA WILL NOT BE ASSIMILATED ANYMORE (DUE TO CONTAMINATION BY CONTRIBUTION FROM THE SURFACE) AND A NEW CLOUD FILTERING WILL BE INTRODUCED FOR THE AMSUB AND MHS DATA. THE ENSEMBLE SYSTEM WILL MAKE USE OF THE WIND PROFILER DATA. THIS SYSTEM WILL ALSO BE USING THE OBSERVATIONS COMING FROM THE FIRST QUALITY CONTROL PROCESS (BACKGROUND CHECK) INSTEAD OF WAITING FOR THE FINAL VARIATIONAL QUALITY CONTROL. THIS RESULTS IN A GAIN OF 40 MINUTES IN ISSUANCE TIME WITH NO SIGNIFICANT DECREASE IN THE FORECASTS QUALITY. THE GEM MODEL ITSELF USED IN THE GLOBAL AND REGIONAL FORECAST SYSTEM REMAIN UNCHANGED EXCEPT FOR A CORRECTION ON THE DIFFUSION OF THE WINDS NEAR THE TOP OF THE MODEL. PERFORMANCE EVALUATION THE ADDITION OF THE NEW DATA IN THE ASSIMILATION SYSTEM WAS TESTED EXTENSIVELY. TWO CYCLES EACH COVERING TWO MONTHS EXTENDING FROM JUNE 15 TO AUGUST 31 2006 AND FROM DECEMBER 20 TO MARCH 9 2007 WERE DONE. FORTY REGIONAL TEST FORECASTS WERE MADE FOR EACH SEASON. THE NEW SYSTEMS WERE ALSO TESTED IN PARALLEL RUNS SINCE THE END OF JANUARY 2008. THE OUPUTS OF THE FORECAST SYSTEMS FOR THE TESTS WERE VERIFIED AGAINST OBSERVATIONS AND AGAINST ANALYSES. THE OUTPUTS OF THE PARALLEL RUNS WERE ALSO EVALUATED BY OPERATIONAL METEOROLOGISTS. ASSIMILATION THE CHANGES REPRESENT AN INCREASE OF ABOUT 50 PERCENT OF THE ASSIMILATED DATA VOLUME. ITS IMPACT IS MULTIPLE. AIRS RADIANCES BRING A BETTER RESOLUTION OF THE TEMPERATURE AND HUMIDITY PROFILES IN CLEAR AIR BY THE NUMBER OF CHANNELS ASSIMILATED EVEN THOUGH THEY MAY BE COLOCATED WITH AMSUA DATA FROM AQUA. IT ALSO ADDS TO THE ROBUSTNESS OF THE SYSTEM. SSM/I RADIANCES ALLOW A BETTER COVERAGE AND ANALYSIS OF HUMIDITY OVER OCEANS IN CLEAR AREAS OR AREAS WITH LITTLE CLOUD. QUIKSCAT WINDS IMPROVE THE POSITIONING OF WEATHER SYSTEMS OVER OCEANS AND POSSIBLY THEIR INTENSITY. GOES SATELLITE WINDS IN THE 3.9 MICRON CHANNEL ARE CONCENTRATED IN THE LOWER LAYERS OF THE ATMOSPHERE AT NIGHT OVER THE OCEANS AND ARE GIVING INFORMATION NOT AVAILABLE BEFORE. THE IMPACT OF THESE SUPPLEMENTAL OBSERVATIONS ON THE ANALYSES IS SIGNIFICANT ESPECIALLY WHERE CONVENTIONAL DATA IS LIMITED. OVER THE CONTINENTS WHERE RADIOSONDES DATA IS CONCENTRATED THE IMPROVEMENTS ARE SMALLER BUT OVER THE GLOBE THE REDUCTION IN THE BIAS OF THE GEOPOTENTIAL IS NOTABLE AT ALL LEVELS FOR MOST REGIONS. GLOBAL MODEL FORECAST EVALUATION OBJECTIVE VERIFICATION INDICATES A SLIGHT BUT CONTINUOUS IMPROVEMENT FOR ALL FORECAST PROJECTION TIMES FOR MASS FIELDS OVER NORTH AMERICA, THE NORTHERN HEMISPHERE AND THE TROPICS. FOR THE SOUTHERN HEMISPHERE WIND AND MASS FIELDS ARE SIGNIFICANTLY IMPROVED. THE HUMIDITY FIELD ALSO SHOWS A SIGNIFICANT GAIN IN THE TROPOSPHERE OVER THE SOUTHERN HEMISPHERE. VERIFICATION AGAINST ANALYSES SHOWS (ANOMALY CORRELATION) A GAIN IN PREDICTABILITY FROM 1 TO 6 HOURS BY DAY FIVE DEPENDING ON SEASON AND HEMISPHERE. QPF VERIFICATION SHOW THE CHANGES TO BE NEUTRAL OVER NORTH AMERICA. THESE CONCLUSIONS APPLY EQUALLY FOR SUMMER AND WINTER TEST CYCLES. OPERATIONAL FORECASTERS COMPARED OPERATIONAL AND PROPOSED MODEL DURING THE PARALLEL RUN. THE PARALLEL GLOBAL MODEL SHOWED A BETTER HANDLE ON THE HUMIDITY FIELD OVER THE PACIFIC AND BETTER QPF FORECAST OVER NORTH AMERICA IN GENERAL. THE MASS FIELDS WERE ALSO BETTER FORECASTED ON THE AVERAGE ESPECIALLY OVER PACIFIC COASTAL REGIONS OF NORTH AMERICA AND IN THE 4 TO 5 DAY FORECAST RANGE. THE OUTPUTS FROM THE GLOBAL FORECAST SYSTEM, INCLUDING SCRIBE, WILL BE AVAILABLE 15 MINUTES LATER OWING TO THE INGESTION OF THE SUPPLEMENTAL DATA. REGIONAL FORECAST MODEL VERIFICATION EVEN IF THE NEW DATA IS IN PRINCIPLE INCORPORATED IN THE REGIONAL ASSIMILATION SYSTEM, THE EARLY CUT-OFF (T+1H35) OF THE RUN LEADS TO LESS NEW DATA BEING AVAILABLE, MORESO FOR SATELLITE DATA. NONETHELESS OBJECTIVE VERIFICATION SHOWS A WEAK POSITIVE IMPACT ON MASS FIELDS AND A NEUTRAL IMPACT ON QPF EXCEPT FOR A SLIGHT DETERIORATION OF THE QPF BIAS ON DAY 2 DURING THE PARALLEL RUN. DURING THE PARALLEL RUN EVALUATION BY OPERATIONAL FORECASTERS LITTLE DIFFERENCE WAS NOTICED WHEN COMPARING WITH THE OPERATIONAL MODEL. THE OUTPUTS FROM THE REGIONAL FORECAST SYSTEM, INCLUDING SCRIBE, WILL BE AVAILABLE 15 MINUTES LATER SINCE IT DEPENDS ON THE GLOBAL FORECAST SYSTEM. ENSEMBLE PREDICTION SYSTEM OBJECTIVE VERIFICATION SHOWED A SMALL REDUCTION IN THE ENSEMBLE MEAN RMS ERROR IN MASS FIELDS FOR DAY 1-6 AND A SMALL IMPROVEMENT IN PRECIPITATION SCORES OVER CANADA IN THE 12-72 HOURS FORECAST RANGE. IMPACTS ON SCRIBE SINCE NO MAJOR CHANGES ON THE BIAS OF THE FORECAST FIELDS WERE NOTED FOR CANADIAN REGIONS, THE IMPACT OF THE NEW DATA ON UMOS AND SCRIBE WILL BE SMALL. FOR MORE DETAILS PLEASE REFER TO THE TECHNICAL NOTE ON THIS TOPIC WHICH CAN BE FOUND AT: HTTP://WWW.SMC.EC.GC.CA/CMC/OP_SYSTEMS/RECENT_E.HTML FOR SPECIFIC QUESTIONS CONCERNING THIS IMPLEMENTATION, YOU CAN WRITE TO: PRODUCTION-INFO(AT)CMC.EC.GC.CA GRIMES ADMA - MSC / SMA - SMC TORONTO