Marine downscaling of a future climate scenario for the North Sea

The SRES A1B scenario for the period 2072-2097 with the Bergen Climate Model (BCM) has been downscaled for the marine climate in the North Sea using the Regional Ocean Model System (ROMS). The results are compared to the 20C3M run for the period 1972-1997. The results show a warming of the North Sea, with a volume average of 1.4 degrees C, and a mean SST change of 1.7 degrees C. The warming is strongest in May-June. Geographically the strongest warming in the North Sea is found towards Skagerrak-Kattegat in the surface waters and in the central North Sea at 50 m depth. The downscaling show a weak increase in the Atlantic inflow to the North Sea. The BCM scenario has a change in the wind stress pattern in the Faeroe Island region. This strengthens the branch of Atlantic Water flowing west of the Faeroes and weakens the flux through the Faeroe-Shetland Channel. As a result both BCM and the downscaling show large changes in the temperature in this area, with weak warming and sometimes cooling south of the Faeroes and strong warming on the north side.