A MSG/SEVIRI simulator for the validation of climate models

We present a simulator that converts 3-dimensional model cloud fields to 2-dimensional MSG-SEVIRI observations. The simulator was used to investigate the uncertainties in the CMSAF cloud physical properties retrieval algorithm in a systematic way, taking into account a large range in cloud optical thickness and surface albedo, as well as variations in cloud cover and multilayer, multiphase clouds. Furthermore we present the application of the simulator to the KNMI regional atmospheric climate model (RACMO), where it was used to derive synthetic satellite images from model scenes to fascilitate a direct comparison of model clouds with observations.