1. Page 1 Hal Ritchie and many collaborators Recherche en Prévision Numérique (RPN) Meteorological Research Division, Science and Technology Branch Expert Meeting on Upper Ocean-Atmosphere Interactions, Exeter, December 2009 Sea Ice and Air-Sea Surface Exchange: Impacts in the Canadian Coupled Atmosphere-Ice Ocean Forecast System

2. 2 Collaborators Research Division (RPN) –Pierre Pellerin, Michel Valin, Djamel Bouhemhem, Greg Smith National Lab for Marine & Coastal Meteorology –Hal Ritchie, Serge Desjardins CMC –Manon Faucher, Francois Roy, Bertrand Denis (CMDN) –Lewis Poulin, Dominic Racette, Doug Bender, Yves Pelletier, Mark McCrady (CMOI) –Richard Moffet (A&P) Regional weather offices –Atlantic & Quebec Storm Prediction Centres –Newfoundland & Labrador Office Canadian Ice Service (CIS) –Tom Carrières, Paul Pestiau Fisheries and Oceans Canada (DFO) –Maurice-Lamontagne Institute (IML) Denis Lefaivre

3. Page 3 1) Impacts in the Gulf of St-Lawrence fully coupled Atmosphere-Ocean- Ice forecast system 2) R&D Strategy to Expand and Globalize the coupled system. Outline:

4. Page 4 Development of the Gulf St-Lawrence forecast system A first operational fully coupled Atmosphere-Ocean-Ice Gulf of St. Lawrence N. Atlantic The Gulf of St. Lawrence (GSL) forecast system: Initiated 13 years ago by the Maurice Lamontagne Institute (DFO) and Recherche en Prévision Numérique (EC) Between January and March the GSL is nearly entirely ice covered Ice conditions can change very rapidly Coastal weather is strongly affected by the ocean conditions. During the ice period, both systems are particularly interdependent. To improve atmospheric forecasts (icing, clouds, fog,…) To improve ocean-ice forecasts (ice, currents, temperature, waves…) To improve services: GSL is a major seaway Users: EC, coast-guard, DFO, maritime transportation, DND Very interesting laboratory: Semi-enclosed sea Circulation is controlled : by tides, exchanges with atmosphere, runoff from land, the seasonal ice cover, and the inflow through the bounding straits

5. Page 5 Models & Coupling strategy Atmosphere: Global Environmental Multi-scale (GEM): –Regional configuration LAM @ 15km - 2.5 km and 58 levels; Ocean: Gulf of St. Lawrence Model (ROM, Saucier et al. 2003): –3D Ocean @ 5km and 73 levels; version 4.9.5 (5.2.2); –Sea-ice (dynamic - thermodynamic); Elastic-viscous-plastic (EVP) model (Hunke & Dukowicz, Los Alamos CICE model, 1997); Thermodynamics: Semtner, 1976; Coupler OASISv3-Gossip (Valcke 2004) Methodology

6. Page 6 Atmosphere Ocean-Ice Each: 600 seconds IR and Vis flux, Humidity, Pressure, Winds, Precipitation, Temperature. Heat and Vapour Flux IR flux. 15 km timestep=600s 5 km timestep=300s Coupler Coupling description

7. Page 7 Ice fraction 48h forecast 2 way coupled Atmosphere-Ocean-Ice An interesting Case Case: Particularly interesting given that the intense atmospheric circulation that dramatically changed the Ice conditions in only 48 hours was preceded by a cold and relatively quiet period.

8. Page 8 C d) A C 0 20 40 60 80 % Anticosti Clouds Ice Water Ice Observation Forecast (coupled) Ice Valid: 14/03/97 20 Z after 44 hours Atmosphere-Ocean-Ice An interesting Case Ice Forecast

9. Page 9 Atmosphere-Ocean-Ice An interesting Case Difference Air temp. Coupled - Uncoupled Impact on surface air temperature

10. Page 10 Impacts on low level clouds (air-ocean exchanges) UncoupledFully coupled a)b) c) Water Ice Clouds AVHRR Nova-Scotia New-Brunswick P-E. I. Cape-Breton M. I. Clouds over Ice Water Ice Atmosphere-Ocean-Ice An interesting Case

11. Page 11 Data: Hourly air & dew point temperature, surface pressure, cloud cover 6-hourly precipitation accumulation Objective Evaluation (Surface observations) 44 stations Operational implementation

12. Page 1210/12/2014Page 12 Mont-Joli, 06 Feb. 2008 GEM Coupled Observations Operational implementation Fully Coupled system VS Operational GEM (48 hours forecast) GEM Operational (Uncoupled) ~ 24 hours

13. Page 13 Impact on atmospheric variables Winter 2008 Forecast hour % Coupled System better (> 50%) Operational implementation Temperature Humidity Clouds Precipitation Surface pressure

14. Page 14 Surface temperature (TT) Forecast hour Dew point temperature (TD) Forecast hour Statistics for February 2008 Uncoupled Fully coupled Operational implementation

15. Page 15 Summary: EC and DFO have successfully developed a fully-interactive coupled atmosphere-ice-ocean forecasting system for the Gulf of St. Lawrence This system will become fully operational at the Canadian Meteorological Centre (CMC) this winter Results during the past year have demonstrated that the coupled system produces improved weather forecasts in and around the GSL during all seasons –Shows that atmosphere-ice-ocean interactions are indeed important even for short-term Canadian weather forecasts Used by Canadian Ice Service, Coast-Guard, Department National Defence Operational Coupled Atmosphere-Ocean-Ice system Gulf of St. Lawrence

16. Page 16 1) Impacts in the Gulf of St. Lawrence fully coupled Atmosphere- Ocean-Ice forecast system 2) R&D Strategy to Expand and Globalize the coupled system. Outline:

17. Page 17 17 Canada requires ocean forecasts and information services for: –Weather prediction –Sea ice prediction (e.g. CCG: seal hunt, navigation) –Fisheries and aquaculture management –Increased understanding of biological field observations –Attribution and mitigation of regional climate change impacts –Risk assessment for extreme events (sea level, waves, currents) –Search and Rescue, dispersion of pollutants Global Coupled System

18. Page 18 Mercator-Canada Partnership Summary: In 2005 Environment Canada, Department of Fisheries and Oceans and Department of National Defense recognized a common need for products and modeling capabilities that can be provided by an operational global coupled atmosphere-ocean-ice data assimilation and prediction system MERCATOR was recommended by an inter-departmental advisory panel to become a partner in the development of an operational Canadian coupled atmosphere-ocean-ice data assimilation and modelling capability Global Coupled System 4 years later: A MOU among the three departments is now in place: Research, Development and Implementation of Operational Coupled Atmosphere- Ocean-Ice Assimilation and Prediction Systems for Canada A letter of intent between Canada and Mercator put in place –Collaborations and Exchanges underway –The current operational ocean model of the Mercator-Ocean group has been installed in Canada and is now used as common research system between DFO-EC An International Memorandum of Understanding (MOU) between Canada and the Mercator Océan is being drafted and is under review –Main objective: Build a medium-long term perspective of collaboration between the two groups

19. Page 19 Core Projects Atmosphere Ice-Ocean Data Assimilation Observations Models Atmospheric Forecasts Products Data Assimilation Observations Models Project 1: Project 1: Atm-Ice-Ocean Coupling (models and data assimilaton) Project 2: Ice-Model Project 4: Project 4: Ice Data Assimilation Ice-ocean Forecasts Products Project 3: Project 3: Ocean Data Assimilation and Ice- Ocean Forecasting Global Coupled System

20. Project 1: Gulf St-Lawrence Atm.-Ocean-Ice Short term High-Resolution Project 3: Great-Lakes Atm.-Lakes-Ice Short term High-Resolution Project 2: Arctic Atm. – Ice Short term forecasts High-Resolution ORCA025 Project 4: Global