Climate Prediction Analysis Using an Ensemble of RegCM Experiments for Central-Eastern Europe

The CORDEX international initiative is the Coordinated Regional Climate Downscaling Experiment in the framework of WCRP (World Climate Research Program). The entire Earth is distributed into 14 different domains being defined to run climate models. Among these domains, the Mediterranean domain (i.e. region 12 covering 30°-50°N, 10°W-45°E) is in the focus of Med-CORDEX. The specific aim of our research group is to contribute to the complex regional climate modeling database with several experiments of one selected model with 50 km horizontal resolution using the mosaic-type subgridding option in order to take into account subgrid processes. For this purpose, RegCM was selected, which is a 3-dimensional, sigma-coordinate, primitive equation model, originally developed by Giorgi et al., and currently available from the ICTP (Abdus Salam International Centre for Theoretical Physics, Trieste, Italy). We completed several experiments for the MED-44 domain using different scenarios (both RCP4.5 and RCP8.5) and different global models (HadGEM2 and MPI-ESM) as initial and lateral boundary conditions driving the regional model. Besides the validation of historical runs (covering 1951-2005), RCP scenarios representing different future conditions are also analyzed for the 21st century (2006-2100). In this contribution we are presenting a complex analysis of an ensemble of 4 experiment using the same regional climate model with special focus on temperature and precipitation conditions. Both mean and extreme climatic conditions are evaluated. The 50-km resolution RegCM-outputs served as input for further downscaling using a horizontal resolution of 10 km for a smaller domain covering Central/Eastern Europe including Hungary. These experiments aims to become the basis of the Hungarian national climate and adaptation strategies by using RegCM results for detailed regional scale climatic projections and specific impact studies (e.g. agriculture, hydrology, health issues, etc.).