NOCN03 CWAO 101233 GENOT TLTP. NO. 002 BILINGUAL MESSAGE - THE FRENCH TEXT FOLLOWS THE ENGLISH TEXT MESSAGE BILINGUE - LE TEXTE FRANCAIS SUIT LE TEXTE ANGLAIS A COUPLED ATMOSPHERE - OCEAN - ICE FORECAST SYSTEM FOR THE GULF OF ST. LAWRENCE WAS DECLARED OPERATIONAL AT THE CANADIAN METEOROLOGICAL CENTRE. STARTING ON JUNE 09 2011, THIS COUPLED SYSTEM WAS LAUNCHED ONCE PER DAY FROM 00 UTC DATA. IT IS THE FIRST OPERATIONAL FULLY INTERACTIVE COUPLED ATMOSPHERE-OCEAN-ICE FORECASTING SYSTEM TO RUN AT ENVIRONMENT CANADA. THE DEVELOPMENT OF THIS SYSTEM IS DONE THROUGH COLLABORATION BETWEEN THE DEPARTMENT OF ENVIRONMENT AND THE DEPARTMENT OF FISHERIES AND OCEANS. 1. MODELS' DESCRIPTION AND CONFIGURATION THE ATMOSPHERIC COMPONENT IS A LIMITED AREA CONFIGURATION OF THE GEM MODEL (GEM-LAM) CENTERED OVER THE GULF OF ST. LAWRENCE (GSL). THIS GEM-LAM MODEL HAS A GRID SPACING OF 15 KM (0.13 DEGREE) ON A RECTANGULAR LATITUDE-LONGITUDE PROJECTION. THE NEEDED LATERAL BOUNDARY CONDITIONS FOR THIS MODEL CONFIGURATION ARE TAKEN AT EVERY HOUR FROM THE 00 UTC REGIONAL DETERMINISTIC PREDICTION SYSTEM (RDPS) OPERATIONAL FORECASTS AT THE SAME RESOLUTION. THE GEM-LAM TIMESTEP IS 450 SECONDS AND THE FORECAST VARIABLES ARE ARCHIVED AT EVERY HOUR. THE OCEANIC COMPONENT IS A 3D OCEAN-ICE MODEL FOR THE (GSL). THIS OCEAN-ICE MODEL COMPUTATIONAL DOMAIN EXTENDS FROM CABOT STRAIT AND BELLE ISLE STRAIT TO QUEBEC CITY AND TO THE HEAD OF THE SAGUENAY FJORD. THE HORIZONTAL RESOLUTION IS 5 KM ON A ROTATED-MERCATOR PROJECTION. THE OCEAN IS LAYERED IN THE VERTICAL WITH A UNIFORM RESOLUTION OF 5 M DOWN TO 300 M DEPTH AND 10 M FURTHER DOWN BELOW. THE SURFACE AND BOTTOM LAYERS ARE ADJUSTED TO THE WATER LEVEL AND LOCAL DEPTH RESPECTIVELY. THE BOUNDARY CONDITIONS FOR RIVER RUNOFFS, TEMPERATURE AND SALINITY ARE TAKEN FROM CLIMATOLOGICAL DATA AND TIDES ARE IMPLICITLY CALCULATED. THE OCEAN-ICE MODEL TIMESTEP IS 225 SECONDS AND THE FORECAST VARIABLES ARE ARCHIVED EVERY HOUR. 2. COUPLING STRATEGY THE TWO-WAY COUPLING OF THIS GEM-LAM AND THE OCEAN-ICE MODEL IS DONE VIA AN EXCHANGE OF SURFACE VARIABLES AND RADIATION FLUXES AT EACH GEM-LAM TIMESTEP (450S). EACH MODEL USES THESE VARIABLES AND/OR FLUXES TO COMPUTE THEIR OWN NET SURFACE BUDGET OF MOMENTUM, HEAT AND FRESH WATER AT THE INTERFACE BETWEEN THE ATMOSPHERE AND THE OCEAN-ICE SYSTEM. IN THIS COUPLING STRATEGY, GEM-LAM USES THE LAND-SEA MASK AND FOUR VARIABLES FROM THE OCEAN-ICE MODEL: THE SEA SURFACE TEMPERATURE (HEREAFTER SST) AND THREE ICE FIELDS (SEA ICE FRACTION, THICKNESS AND SURFACE TEMPERATURE). THE OCEAN-ICE MODEL USES SEVEN VARIABLES FROM GEM-LAM OUTPUT: THE SURFACE AIR AND DEW POINT TEMPERATURE AT A DIAGNOSTIC LEVEL OF 1.5M, THE WIND VECTOR COMPONENTS AT A DIAGNOSTIC LEVEL OF 10M, THE SOLAR AND INFRARED SURFACE FLUXES AND THE PRECIPITATION RATE. THE RE-MAPPING BETWEEN THE 15KM RESOLUTION LATITUDE-LONGITUDE GEM-LAM GRID AND THE 5KM OCEAN-ICE MODEL GRID IS DONE WITH HORIZONTAL LINEAR INTERPOLATION/AGGREGATION, USING A LAND-SEA MASK AND EVOLVING SEA ICE MASK. 3. OPERATIONAL FORECAST SETUP THE FORECAST STRATEGY INCLUDES THREE MAIN PARTS: (1) AN OCEANIC PSEUDO-ANALYSIS CYCLE, (2) A SUPERIMPOSED SEA ICE ANALYSIS BASED ON DIRECT INSERTION OF RADARSAT ANALYSES AND (3) A COUPLED FORECAST CYCLE. 3.1 OCEANIC PSEUDO-ANALYSIS AND ICE ANALYSIS SYSTEM THE OCEANIC PSEUDO-ANALYSIS CYCLE RUNS ON A DAILY BASIS FOR PREDICTING THE PRESENT GSL OCEANIC STATE. THIS SYSTEM IS THEN COMBINED WITH ICE FIELDS FROM THE SEA ICE ANALYSIS SYSTEM.. THIS CYCLE PROVIDES A 3D BALANCED OCEANIC SOLUTION FOR THE INITIALIZATION OF THE COUPLED FORECAST SYSTEM. THE SOLUTION INCLUDES OCEAN TEMPERATURE, SALINITY, CURRENTS ANDWATER LEVELS, AND ICE FRACTION, THICKNESS AND TEMPERATURE. THE OCEANIC PSEUDO-ANALYSIS SYSTEM HAS BEEN VALIDATED AND VERIFIED EXHAUSTIVELY: FROM NUMEROUS R AND D APPLICATIONS OF OCEAN-ICE MODEL IN THE LAST DECADE, TO MORE RECENT VERIFICATIONS OF SEA SURFACE FIELDS IN THE METEOROLOGICAL FORECAST CONTEXT. INDEED, FOR SEA SURFACE TEMPERATURE (SST) ACCURACY, THE GSL PSEUDO-ANALYSIS IS COMPARABLE TO THE CMC ANALYSIS BASED ON SATELLITE RETRIEVALS. 3.2 COUPLED FORECAST THE COUPLED FORECAST CYCLE IS A 48 H SIMULATION BASED ON 00 UTC DATA WHERE BOTH MODELS (GEM-LAM AND OCEAN-ICE) RUN AT THE SAME TIME AS DESCRIBED IN SECTION 2. IT PROVIDES 00-48 H WEATHER, SEA ICE AND OCEAN FORECASTS. 4. OUTPUTS FOR THE ATMOSPHERIC PART, THE OUTPUTS ARE SIMILAR TO THOSE OF THE RDPS OPERATIONAL MODEL. FOR THE OCEAN-ICE SYSTEM, THERE ARE NEW VARIABLES. PART OF THE OUTPUTS WILL BE DISSEMINATED TO THE CANADIAN ICE SERVICE (CIS) AND THE MAURICE LAMONTAGNE INSTITUTE (MLI) IN GRIB2 FORMAT: ICE FRACTION AND THICKNESS (ICEC, ICETK), ICE VELOCITIES (UICE, VICE), SURFACE OCEAN CURRENTS (UWAT, VWAT), ICE INTERNAL STRESS COMPONENTS (UIST, VIST), AND ICE SEVERITY INDEX (SEVI). GRIB2 DATA WILL ALSO BECOME AVAILABLE ON OUR PUBLIC DATA SERVER (DATAMART) IN THE COMING WEEKS. 5. FORECAST EVALUATION THE EVALUATION OF THE COUPLED SYSTEM IS DIVIDED IN TWO PARTS. A FIRST PART OF THE EVALUATION WAS DONE FROM HINDCAST RUNS FOR WINTER AND SUMMER 2008 TO EVALUATE THE BENEFITS OF THE COUPLED SYSTEM DURING A DEVELOPMENT PHASE AND PRIOR TO ITS FINAL IMPLEMENTATION FOR AN OPERATIONAL RUN. A SECOND PART OF THE EVALUATION WAS DONE DURING EXPERIMENTAL RUNS FOR WINTERS 2008 TO 2010, FOCUSING ON A MORE SUBJECTIVE EVALUATION OF DAILY WEATHER AND OCEAN-ICE FORECASTS. THE EVALUATION OF THE COUPLED SYSTEM WAS DONE IN COLLABORATION WITH THE CANADIAN ICE SERVICES (CIS), THE MAURICE-LAMONTAGNE INSTITUTE (MLI), THE NATIONAL LAB FOR MARINE AND COASTAL METEOROLOGY (NLMCM), THE NEWFOUNDLAND AND LABRADOR WEATHER OFFICE, THE ATLANTIC AND QUEBEC STORM PREDICTION CENTRES AND THE ANALYSIS AND PREDICTION SECTION AT CMC. IN GENERAL, IT WAS FOUND THAT THE COUPLED SYSTEM PROVIDES A BETTER REPRESENTATION OF THE GSL WINTER SEA SURFACE CONDITIONS THAN THE CURRENT RDPS OPERATIONAL SYSTEM. THIS IS DUE TO A BETTER INITIAL CONDITION OF SEA ICE (COVERAGE AND THICKNESS) OVER THE GSL AND ITS EVOLUTION THROUGH THE COUPLING. FOR COASTAL REGIONS, THE MAIN EFFECT WAS AN IMPROVEMENT IN SURFACE AIR TEMPERATURE AND HUMIDITY FORECASTS. THE ATMOSPHERIC FORECAST COMPONENT IS REFERRED TO AS THE REGIONAL DETERMINISTIC PREDICTION SYSTEM-COUPLED TO THE GULF OF ST-LAWRENCE (RDPS-CGSL) AND THE MARINE ANALYSIS COMPONENT IS REFERRED TO AS THE REGIONAL MARINE PREDICTION SYSTEM-GULF OF ST-LAWRENCE (RMPS-GSL). FOR MORE DETAILS PLEASE REFER TO THE TECHNICAL NOTE ON THIS TOPIC WHICH WILL BE AVAILABLE SHORTLY IN THE CMC PRODUCT GUIDE AT: HTTP://COLLABORATION.CMC.EC.GC.CA/CMC/CMOI/PRODUCT_GUIDE IN THE SECTION OF THE GUIDE TITLED CHANGES TO OPERATIONAL SYSTEMS FOR SPECIFIC QUESTIONS CONCERNING THIS IMPLEMENTATION, YOU CAN WRITE TO: PRODUCTION-INFO(AT)CMC.EC.GC.CA =================================================================== ==================================== LE CENTRE METEOROLOGIQUE CANADIEN A MIS EN OPERATION UN SYSTEME DE PREVISION COUPLE ATMOSPHERE-OCEAN-GLACE SUR LA REGION DU GOLFE DU SAINT-LAURENT. A PARTIR DU 09 JUIN 2011, CE MODELE COUPLE EST INTEGRE UNE FOIS PAR JOUR A PARTIR DES DONNEES DE 00 UTC. C'EST LE PREMIER SYSTEME OPERATIONNEL DE PREVISION COUPLE COMPLETEMENT INTERACTIF CHEZ ENVIRONNEMENT CANADA. LE DEVELOPPEMENT DE CE SYSTEME EST EN COLLABORATION ENTRE ENVIRONNEMENT CANADA ET PECHES ET OCEANS CANADA. 1. DESCRIPTIONS DES MODELES ET CONFIGURATIONS LA COMPOSANTE ATMOSPHERIQUE EST UNE CONFIGURATION A AIRE LIMITEE DU MODELE GEM (GEM-LAM) CENTRE SUR LE GOLFE DU SAINT-LAURENT (GSL). LE DOMAINE DE CALCUL CONSISTE EN UNE GRILLE AYANT UN ESPACEMENT DE 15 KM (0.13 DEGRE) SELON L'HORIZONTALE SUR UNE PROJECTION RECTANGULAIRE LATITUDE-LONGITUDE. LES CONDITIONS FRONTIERES DE CE MODELE SONT FOURNIES A CHAQUE HEURE PAR LA PASSE 00 UTC DU SYSTEME DE PREVISION REGIONAL DETERMINISTE (SPRD) OPERATIONNEL QUI EST A LA MEME RESOLUTION. LE PAS DE TEMPS DU MODELE GEM-LAM EST DE 450 SECONDES ET LES SORTIES SONT ARCHIVEES AUX HEURES. LA COMPOSANTE OCEANIQUE EST UN MODELE GLACE-OCEAN 3D SUR LE GOLFE DU SAINT-LAURENT (GSL). LE DOMAINE DE CE MODELE COUVRE UNE REGION ALLANT DU DETROIT DE CABOT ET LE DETROIT DE BELLE ISLE JUSQU'A LA VILLE DE QUEBEC ET A LA TETE DU FJORD DU SAGUENAY. SA RESOLUTION HORIZONTALE EST DE 5 KM SUR UNE PROJECTION MERCATOR TOURNEE. LES NIVEAUX VERTICAUX DANS L'OCEAN SONT A INTERVALLE DE 5 M JUSQU'A 300 M DE PROFONDEUR ET SONT A INTERVALLE DE 10 M PAR LA SUITE. LES COUCHES DE SURFACE ET DE FOND SONT AJUSTEES AU NIVEAU DE L'EAU ET A LA PROFONDEUR DE L'OCEAN. LES CONDITIONS FRONTIERES POUR TENIR COMPTE DE L'APPORT D'EAU DES RIVIERES, DE LA SALINITE ET DE LA TEMPERATURE SONT FOURNIES PAR LES DONNEES CLIMATOLOGIQUES ET LES MAREES SONT CALCULEES IMPLICITEMENT. LE PAS DE TEMPS DU MODELE OCEAN-GLACE EST DE 225 SECONDES ET LES VARIABLES PREVUES SONT PREVUES ET ARCHIVEES AUX HEURES. 2. STRATEGIE DE COUPLAGE LE COUPLAGE BIDRECTIONNEL ENTRE CE GEM-LAM ET LE MODELE OCEAN-GLACE SE FAIT VIA UN ECHANGE DE VARIABLES DE SURFACE ET DE FLUX RADIATIFS A TOUS LES PAS DE