Progress in the GEM-NEMO coupled data assimilation and prediction system

Environment Canada (EC), Fisheries and Oceans Canada (DFO), and the Department of National Defence (DND) require environmental information products and capabilities that could be provided by operational regional and global coupled atmosphere-ice-ocean data assimilation and prediction systems. This need has led to the creation of a new tri-ministerial initiative called the Canadian Operational Network of Coupled Environmental PredicTion Systems (CONCEPTS). CONCEPTS, in close collaboration with the French operational oceanographic centre Mercator-Océan, is providing a framework for research and operations on coupled atmosphere-ocean-ice prediction in Canada. Operational activity in CONCEPTS is based on coupling the Canadian atmospheric GEM model with the Mercator ice-ocean forecasting system based on the Nucleus for European Modelling of the Ocean (NEMO) ice-ocean model. The Mercator data assimilation system is based on a multi-variate SEEK data assimilation method that assimilates sea level anomaly, sea surface temperature (SST) and in situ temperature and salinity data. Using the Mercator forecasting system, weekly 1/4° resolution global 10-day ice-ocean forecasts are being produced in parallel to those produced by Mercator, with 3 main modifications: First, the forecasts are driven by atmospheric forecasts from GEM that include diurnally-varying radiative fluxes. In addition, the SST analyses from the Canadian Meteorological Centre (CMC) are assimilated in place of the NCEP RTG analyses used by Mercator. Finally, ice fields are initialized using a 3DVAR ice analysis system that assimilates the manual ice analyses from the Canadian Ice Service, Radarsat manual analyses as well as AMSR-E data. This ice-ocean forecasting system is now being used in a coupled framework with the operational GEM atmospheric forecasting system at CMC to investigate the impact of coupling on short to medium range forecasts. This talk will provide an overview of these activities, summarize results to date, and discuss plans for new and future operational systems.