Ocean modelsAt the Nansen Center, we are developing the data assimilation system TOPAZ which is based on the ocean model HYCOM, the ecosystem model ECOSMO, the sea-ice model CICE, and our own developed data assimilation method Ensamble Kalman Filter. TOPAZ is used for forecasting physical conditions such as for example temperature, salinity and currents, and biogeochemical conditions such as nutrient salt content and plankton quantities. In addition, the system can be used to forecast sea-ice conditions. We can also use TOPAZ to produce reanalyses of the conditions in the ocean. The use of data assimilation makes it possible to use data from both satellites and point measurements in the ocean, and to include the data in the model to produce the most precise ocean forecasts and reconstructions possible. For more information, contact research leader Annette Samuelsen.