Near future changes of extreme precipitation over complex terrain in Central Europe derived from high resolution RCM ensemble simulations

摘要

An ensemble of high-resolution regional climate simulations is used to assess the effect of near future climate change on mean and extreme precipitation in a part of Central Europe with complex topography. The ensemble consists of high-resolution simulations with the COSMO-CLM (CLM) regional climate model (RCM) using several realizations of the driving general circulation models (GCMs) ECHAM5 and HadCM3. The study is focussed on the changes in the near future (2011-2040 compared to 1971-2000) which are relevant for planning purposes. The mean winter precipitation shows a spatially uniform increase, summertime mean precipitation is likely to decrease slightly. For extreme precipitation the simulations exhibit an increase on the average for both seasons, but for different reasons. The changes in winter are proportional to the increase in total precipitation, whereas in summer a broadening of the precipitation distribution is found. The spatial change patterns in summer are much more heterogeneous than in winter, with regions of significant increase and decrease sometimes close to each other. The plausibility of the findings is assessed in terms of ensemble consistency. The area mean changes found for the ensemble of CLM simulations were consistent with the change signals derived from a larger but coarser resolved ensembles using several RCMs and driving GCMs. In addition, it was found that the simulated near future precipitation changes in the study region during summer generally agree with trends observed during the last decades.