Sea-ice modelling

The ice season in the Baltic Sea lasts up to 7 month and year-to-year variations of the ice coverage are very large. Since sea ice prevents heat and moisture exchange between ocean and atmosphere, a sea ice component, which is coupled to the regional Baltic Sea models, is essential for ocean modelling.

The numerical equations of a sea ice model describe the relevant processes that influence ice evolution. They consist of a thermodynamic and a dynamic part.

The thermodynamic part takes all processes into account that influence ice growth and melt (dependent on e.g., air and ocean temperatures, ocean salinity, and albedo).

The dynamic part includes sea ice motion, which is mainly due to winds and ocean currents. Since the processes involved are too complex to be exactly described by mathematical equations, the models are approximations of the most relevant processes. As such, Baltic Sea ice models provide valuable information and are particularly important for the increasing ship traffic in the Baltic, which depends crucially on reliable ice forecasts.