Simulated regional climate change in the Carpathian Basin using ENSEMBLES model simulations

Spatial resolution of global climate models (GCMs) are inappropriate to describe regional climate processes; therefore, GCM outputs may be misleading to compose regional climate change scenarios for the 21st century. In order to provide better estimations for regional climate parameters, fine resolution regional climate models (RCM) can be used. RCMs are limited area models nested in GCMs, i.e., the initial and the boundary conditions of RCMs are provided by the GCM outputs. In order to estimate the regional climate change expected in the Carpathian Basin located in Central/Eastern Europe, outputs from several RCMs (from the completed European project ENSEMBLES) are summarized and analyzed using A1B scenario. For the selected target region, composite maps of expected change in temperature and precipitation are generated using the RCM simulations (with 25 km spatial resolution) for the periods of 1961-1990 (as the reference period), 2021-2050, and 2071-2100. In order to estimate the bias of the different RCMs, ERA-40 driven runs are compared to the so-called E-OBS datasets containing daily temperature and precipitation values. Then, for the evaluation of annual, seasonal, and monthly expected climatic changes, GCM-driven runs of the reference and the future periods are compared. The results suggest that the temperature of the selected region is expected to increase in the whole year. This warming is about 1-2 °C, and 3-4 °C for 2021-2050, and 2071-2100, respectively. In case of precipitation, the annual sum is not expected to change significantly in the Carpathian Basin. The winter and autumn precipitation is likely to increase while summer and spring precipitation is projected to decrease during the 21st century.