A coupled ice-ocean model supporting winter navigation in the Baltic Sea. Part 2. Thermodynamics and meteorological coupling.

Type: Report
Series: RO 21
Author: Anders Omstedt och Lief Nyberg


For the first time a coupled ice-ocean model system simulating both  dynamic and thermodynamic processes has been run operationally for the Baltic Sea. The dynamical part of the system is based upon a two-dimensional coupled ice-ocean model that resolves the horizontal space and time, and the thermodynamic part of the system is based upon a one-dimensional coupled ice-ocean model that resolves the vertical space and time for different regions in the Baltic Sea. The system was forced using meteorological fields from the HIRLAM system and was run in operational mode during the winter of 1993/1994. The forecasted parameters were: water cooling, ice formation, ice growth and decay, ice drift and ridging, vertical mean currents, sea levels and water warming. The general experience from the winter was most satisfactory and the model system forms a good base for forecasts and further research.

During the winter of 1993/1994 a doser coupling between the ice-ocean system and the HIRLAM system has been tested, illustrating the importance of using accurate ice fields in the HIRLAM system.