Evaluation of Regional Climate Model Surface Solar Radiation Patterns Over Europe Using Satellite-Based Observations and Radiative Transfer Calculations

Abstract

The ability of RegCM4 regional climate model to simulate surface solar radiation (SSR) patterns over Europe is assessed through an evaluation of a decadal simulation against satellite-based observations from the Satellite Application Facility on Climate Monitoring (CM SAF). The model simulates adequately the SSR patterns over the region slightly overestimating SSR (bias of ~+2.5 % for the period 2000–2009). Cloud macrophysical and microphysical properties from RegCM4 such as cloud fractional cover (CFC), cloud optical thickness (COT) and cloud effective radius (Re) are evaluated against data from CM SAF. The same is done for aerosol optical properties such as aerosol optical depth (AOD), asymmetry factor (ASY), and single scattering albedo (SSA) using data from the MACv1 aerosol climatology, and other parameters, such as surface broadband albedo (ALB) using data from the CERES satellite sensors, and water vapor amount (WV) using data from the ERA-Interim reanalysis. The good agreement between RegCM4 and satellite-based SSR observations is a result of counterbalancing effects of these parameters. The contribution of each parameter to the RegCM4-CM SAF SSR deviations is estimated with the combined use of the aforementioned data and a radiative transfer model (SBDART). CFC, COT and AOD are the major determinants of these deviations.