«TOPAZ» is a coupled ocean-sea ice model that covers the North Atlantic and Arctic oceans. It is part of EU's MyOcean project. TOPAZ is primarily developed at the Mohn-Sverdrup Centre (NERSC) and run operationally at met.no. The system consists of the ocean model HYCOM with associated sea ice module. The model has a horizontal resolution between 11 km and 16 km, and has 22 'hybrid' verical layers (a mixture between geopotential, isopycnal and terrain-following layers). An advanced assimilation system, based on the Ensemble Kalman Filter (EnKF), is used to produce best estimates of the ocean state from the model and from observations. The system produces analyses of the ocean state once per week, but also produces new 10-day forecasts every day (using more accurate atmospheric forcing fields every day).
«Arctic20» is another coupled ocean-sea ice model that covers parts of the northern North Atlantic and the entire Arctic Ocean. It is based on the Regional Ocean Modelling System (ROMS). Arctic20 has a horizontal grid resolution of 20 km and has 35 terrain-following vertical layers. Arctic20 currently has an assimilation system sea surface temperature (SST) and sea ice concentration based on optimal interpolation and incremental update via nudging. Estimates of the ocean state and 5-day forecasts are produced every day. Work in underway to implement a more advanced assimilation system (based on 4D-var) in 2012-2013.
The «WAM» model makes predictions of surface gravity waves (significant wave height and direction) for the North Atlantic and Arctic oceans. Various model set-ups exist, ranging in horizontal resolution between 10 km to 50 km.