Evaluation of the Sensitivity of the Updated RegCM4 Model to Physics Parameterizations over the Mediterranean Region: Precipitation and Temperature Simulations

Abstract

Τhe main purpose of this research is to study the sensitivity of regional climate model RegCM4.4.5.1 to the different physics parameterization schemes in the Mediterranean region. The spatial resolution of the model is 25 × 25 km. Different ERA-Interim-driven simulations were performed with changes in the model’s configurations for the time period 1981–1990. The different simulated data of temperature and precipitation were processed seasonally and the differences between the simulations were examined. The statistical significance of the differences is calculated with Student’s t-test. Aiming a more detailed evaluation of the changes that occur, a division of the area of study into five sub-regions was performed according to the common EURO-CORDEX analysis domain and the Taylor diagrams for the examined parameters were calculated. From the analysis of the results it was found that Grell, Mixed, UW-PBL and CORINE simulations present a cold bias, while in BATS1e run temperature is increased. Additionally, Grell, Mixed and UW-PBL simulations present a decrease of precipitation except for winter, where in Grell simulations total precipitation is increased. In BATS1e run an increase of the parameter is detected. Finally, changes in land cover led to a reduction of the parameter during winter and an increase in summer.

Keywords

• RegCM4
• physics parameterization schemes
• precipitation
• temperature