Modeling extreme precipitation events—a climate change simulation for Europe

The regional climate model REMO 5.1 has been applied to the European region to investigate the impact of future climate changes on the frequency and intensity of extreme precipitation events. For todayʹs climate, not only the climatological mean precipitation, but also the 10- and 20-year return levels of daily precipitation are captured fairly well by the use of the following model configuration: REMO 5.1 at 0.5° resolution is driven by an atmospheric global climate model HadAM3H control simulation at the lateral boundaries. Sea surface temperature (SST) and sea ice distribution (SID) are prescribed from the observed data set HadISST1. In mountainous regions, the differences between simulated and observed return levels are larger than in flat regions. Here, a higher horizontal resolution could probably further improve the results. The regional scenario simulation has been carried out with REMO 5.1 driven by a HadAM3H scenario simulation. This simulation is consistent with the SRES-A2 emission scenario and uses changes in sea surface temperature and sea ice distribution simulated by the coupled global climate model HadCM3. Large increases of the precipitation return levels for the 10- and 20-year return periods are simulated in 2070–2100 compared to 1960–1990. Nearly all regions are affected by higher return levels, even if the mean precipitation decreases in some regions. In most regions, the return levels are increasing up to 50%. In the Baltic Sea region, there are increases by more than 100%, which, however, can be partly related to a very strong increase in the sea surface temperature in the coupled global climate model simulation. This increase is stronger compared to other global climate model simulations and very pronounced in the Baltic Sea.