Regional climate simulations for the Barents Sea region

The vulnerability of the Barents Sea region to climate change is under investigation in the context of the EU Project BALANCE (http://balance1.uni-muenster.de). Today's climate of the Barents Sea region has been simulated using the regional climate model REMO driven by Analysis (since 1994) and by Reanalysis (1979–1993) of the European Centre for Medium-Range Weather Forecasts (ECMWF) from 1979 to 2000 with a horizontal resolution of about 55 km. The results have been validated using observations from the Climatic Research Unit (CRU data) for 2-m temperature and precipitation for land areas only. The differences between the REMO simulation results and the CRU data are of the same order of magnitude as the deviations between CRU data and ERA-40 data (Reanalysis data of the European Center for Medium-Range Weather Forecasts). To investigate a possible future climate development a 140-year-long transient simulation from 1961 to 2100 has been carried out using REMO. In this experiment, called the CCC run (Control and Climate Change run), REMO has been driven by ECHAM4/OPYC3 following the IPCC-SRES B2 scenario. The annual mean 2-m temperature of the CCC run shows a clear trend as expected, the 2-m temperature increases by 5 deg.C by the end of the century. The Arctic Climate Impact Assessment reports a 1.5 deg.C temperature increase from 1960 to today, which is in good agreement with our results. From 1960 to 2000 the observed annual mean temperature for the Arctic rises exactly in the same way as in the REMO simulation for the Barents Sea only. Three 20-year periods have been defined in order to analyze differences among these time slices. A stronger warming in January than in July is evident for all time slices. As expected, the warming is enhanced for the period 2041–2060 as compared with that for the earlier period (2011–2030). The largest warming occurs along the sea ice edge and over Russia during the winter months.