IMPROVEMENTS IN THE SIMULATION OF SURFACE CLIMATOLOGY OVER THE EUROPEAN REGION WITH A NESTED MODELING SYSTEM

Is this paper we report on the results of a present day climate simula tion over the European region using a Regional Climate Model (RegCM)ne sted within a General Circulation Model (GCM). Precipitation and surfa ce air temperature results over different European subregions are comp ared with observations and with results from previous simulations by M arinucci and Giorgi [1992] and other modeling groups. Based on a numbe r of measures of simulation skill such as monthly and seasonal biases and spatial correlations, the RegCM performance is substantially impro ved compared to that of Marinucci and Giorgi [1992], it compares well with that of other recent experiments and it is better than that of th e driving GCM. Seasonal precipitation and surface air temperature bias es over European subregions of 10(5)-10(7) km(2) size are mostly in th e range of +/-25% of observations and +/-2 degrees C, respectively. Th ese biases appear to represent the level of accuracy characteristic of present regional modeling systems over Europe at the seasonal and reg ional scale.