Model validation and drought assessment with a regional climate model over Moldova

We assessed drought characteristics in the Republic of Moldova based on the Standardized Precipitation Index (SPI) calculated from monthly precipitation data simulated by the Regional Climate Model RegCM3. The RegCM simulations were conducted at a horizontal resolution of 10 km in the framework of EU-FP6 project Central and Eastern Europe Climate Change Impact and Vulnerability Assessment (CECILIA). The domain was centered over Romania at 46 deg N, 25 deg E and included the Republic of Moldova. We validated the model ability to simulate monthly temperature and precipitation by comparing the model simulations forced by ERA40 with the observations from CRU TS2.0 dataset and station observations for the period 1961-1990. The RegCM simulations (control and scenario runs) forced with the ECHAM5 Global Circulation Model (GCM) have been corrected against the systematic errors induced by the GCM. After the bias correction, the annual cycle of temperature and precipitation is analyzed by comparing the model simulations conducted under A1B scenario for the periods 2021-2050 and 2071-2100 with the control run for the period 1961-1990. The characteristics of the drought for the current climate were assessed based on SPI calculated for 1-24 month lags from CRU dataset and station observations. The SPI for 1, 3, 6, 12, 18, and 24-month lag was calculated and analyzed for RegCM simulations. The results show that the model underestimates the severity of droughts.