Improvements in the simulation of surface climatology over the European region with a nested modeling system

Abstract

In this paper we report on the results of a present day climate simulation over the European region using a Regional Climate Model (RegCM) nested within a General Circulation Model (GCM). Precipitation and surface air temperature results over different European subregions are compared with observations and with results from previous simulations by Marinucci and Giorgi [1992] and other modeling groups. Based on a number of measures of simulation skill such as monthly and seasonal biases and spatial correlations, the RegCM performance is substantially improved compared to that of Marinucci and Giorgi [1992], it compares well with that of other recent experiments and it is better than that of the driving GCM. Seasonal precipitation and surface air temperature biases over European subregions of 105–107 km² size are mostly in the range of ±25% of observations and ±2°C, respectively. These biases appear to represent the level of accuracy characteristic of present regional modeling systems over Europe at the seasonal and regional scale.