Regional Climate Model Experiment Using RegCM Subgridding Options in the Framework of Med-CORDEX

Our research group is participating in the Med-CORDEX international initiative of the CORDEX program in the framework of WCRP (World Climate Research Program). The specific aim is to contribute to the complex regional climate modelling database with RegCM experiments with 50 km horizontal resolution using subgridding option in order to take into account subgrid processes. As being part of the Med-CORDEX initiative, our model domain contains the MED-44 CORDEX area covering the Mediterranean region of Europe (30°-50°N, 10°W-45°E).

RegCM is a 3-dimensional, sigma-coordinate, primitive equation model, originally developed by Giorgi et al. Currently, it is available from the ICTP (Abdus Salam International Centre for Theoretical Physics). We already completed a few experiments (using mainly ERA-Interim data, and HadGEM2 global model outputs as initial and lateral boundary conditions) with 50 km resolution and more experiments are planned (using further HadGEM2, ECHAM5, MPI-ESM global model outputs for driving the regional climate model). Besides the historical runs (covering 1981-2010), new scenarios – RCP8.5 and RCP4.5 – are also analyzed for the 21st century. In this contribution we are presenting the comparison of ERA- and HadGEM-driven experiments for temperature and precipitation.

The 50-km resolution RegCM-outputs will serve as an input for further downscaling using 10 km as a horizontal resolution for a smaller domain covering Central Europe with special focus on Hungary. These experiments will be the basis of the Hungarian national climate and adaptation strategies by using RegCM results for detailed regional scale climatic projections and specific impact studies.