Study of storm weather situations in observation and ECHAM3/T42 model simulation

Abstract

In this paper, we provide an estimation of the seasonal distribution of strong wind and storm weather situations in an ECHAM3/T42 climate model simulation in relation to observed conditions. Observational data of the German Eight and the southern Baltic Sea are taken to compare observations and climate model simulation. The results of the study show significant differences in the seasonal Frequency of occurrence for strong wind and storm weather situations between simulation and observations. A new objective classification routine for detecting single strong wind and storm weather situations (Bft 7 and more) in coarse resolution models is used to validate the large-scale parameters of those events in the climate simulation. The objective classification routine is able to detect strong wind and storm weather situations of two flow regimes in the German Eight in winter. The routine is applied to the ECMWF Re-Analysis (T42 resolution) and to a climate simulation of the northern Hemisphere, which was performed with the ECHAM3/T42. It is shown that the large-scale parameters of single strong wind and storm weather situations are simulated quire realistically in the ECHAM3/T42.