Detection of climate change in Europe by analyzing European atmospheric circulation patterns from 1881 to 1989

Summary The time series of classified European atmospheric circulation patterns for the time period of 1881–1989 are analyzed. Frequencies of several circulation types changed considerably during the last years, showing extremes never reached before. Changes can be observed both in the annual frequencies and in the seasonal ones for many circulation types. The time series were analyzed for homogeneity using non-parametric statistical methods. The annual cycle shows an increase of the frequency of zonal circulations in winter (December and January) and a corresponding decrease of cold meridional circulations. The climatological consequences of this are more frequent mild and humid winters in Central Europe, with precipitation mostly falling as rain. Change points in the series occurred with high probability during the seventies. Examples demonstrate the coupling of circulation patterns to temperature and precipitation.With 9 Figures