The Baltic Sea modelling using coupled ROMS and CICE models.

The coupled ice-ocean model of the Baltic Sea has been prepared to simulate the basic physical parameters. The system is based on sigma-coordinates the Regional Ocean Modelling System (ROMS) and the Los Alamos Sea Ice Model (CICE) and such coupled system was never adapted for Baltic Sea region. It is configured for two horizontal resolutions (1.25 NM and 0.5 NM) that are currently in use with 30 and 26 vertical layers respectively. Both models are forced by two atmospheric data sets: ERA5 and UERRA. Lateral boundary conditions are implemented in Kattegat region as an assimilated sea level, temperature and salinity. Also run off from the catchment model (Balt-HYPE) that covers whole Baltic Sea region have been applied.
Preliminary results from the first few years of the simulation are very promising. The introduced boundary conditions are stable, and the simulation seems to work correctly.
The first comparisons with the Parallel Ocean Program (POP) model, previously used with the same horizontal resolution suggest the model meets the expectations related to the correct work of the Danish Straits, the transport of water masses in the bottom layers and have better dynamics and correctly simulates the free surface. 
The simulations have been performed since 1992. ROMS model results will be presented in comparison with other data delivered by: in-situ measurements during research cruises (point and cross-sections), satellite imaging, modelling. If it will be possible, comparisons with data based on gliders measurements from The Voice of the Ocean are going to be shown.

This study was funded by the NCN “Turbulent Mixing in the Slupsk Furrow” grant number 2019/B/ST10/02189
Calculations were performed using computers of the Academic Computer Centre in Gdańsk.