Dresden 2009 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 30: Nonlinear stochastic systems

DY 30.11: Talk

Friday, March 27, 2009, 12:45–13:00, ZEU 118

More and more weather records - Is global warming to blame? — •Gregor Wergen and Joachim Krug — Institut für Theoretische Physik Köln, Zülpicherstr. 77, 50937 Köln

If one believes in current media coverage it seems very simple: Due to the significant, largely anthropogenic, warming of the world's average temperature, more and more weather extremes occur. Every time we have a record breaking daily maximum temperature, or an immense amount of precipitation in a certain timespan, this is intuitively blamed on global warming. However mathematically the relation between an increasing mean value and the occurrence of records is far from trivial and not completely understood. This relation and its relevance to the analysis of weather data is the subject of this talk. Given an underlying distribution, we consider the probability that an event in a succession of events is a record, when the distribution itself is shifting, or altering its form. We found some approximations that are useful for the comparison with historical climate recordings. We obtained data for the daily maximum and daily minimum temperature and the daily precipitation amount from thousands of weather stations in Europe and the United States and analyzed them with regard to record events. The results are largely in accordance with what we predict from our calculations, but also reveal some interesting deviations.