Optimization of a Regional Climate Model for High Resolution Simulations over Greece
A set of six yearly high resolution (10 × 10 km) regional climate simulations were carried out over Greece using RegCM3 in the framework of the project GEOCLIMA based on different setups for the convective scheme. Specifically, the simulations comprised two experiments using the Grell convective scheme with Fritsch-Chappell (FC) closure assumption and four experiments using the Emanuel convective scheme. The aim of the study is the optimization of the model for Greece by comparing simulated values of near surface temperature, precipitation and cloudiness with the respective observed values at 84 Greek stations. The model domain is nested to a coarser RegCM3 European domain (at a resolution of 25 × 25 km) driven by the ERA-40 reanalysis dataset. Simulations using the modified Emanuel convective scheme reduce mean bias (and RMSE) in temperature over 25% (20%), in cloudiness over 20% (10%) and in precipitation over 70% (40%). Results show that the model for the Greek area is more sensitive to changes in autoconversion threshold than changes in relaxation rate.
KeywordsRoot Mean Square Error Regional Climate Model Mean Absolute Error Convective Scheme Total Cloud Cover
The research has been co-financed by the European Union (European Regional Development Fund) and Greek national funds through the Operational Program “Competitiveness and Entrepreneurship” of the National Strategic Reference Framework (NSRF) – Research Funding Program COOPERATION 2009 (no 09ΣYN-31-1094, Title “Development of a Geographic Climate Information System”). The later boundary conditions for our simulations were provided by Earth System Physics Section, ICTP, Trieste, Italy.