Frei, C. (Atmospheric Physics, ETH-Zⁿrich, Switzerland)
Lⁿthi, D. (same affiliation)
Davies, H.C. (same affiliation)
SchΣr, C. (same affiliation)
Severe precipitation systems over Southern Europe and the Alpine region are often associated with intense moisture transport from the Mediterranean sea, contributing as a trigger of and moisture supply for convective complexes. As the atmospheric moisture transport capacity is strongly temperature dependent it could be expected that heavy precipitation (and the regional hydrological cycle in general) is sensitive to the anticipated global warming. We examine this sensitivity using simulations with a regional climate model for an idealised warming scenario. The scenario involves a stipulated uniform 2K warming and associated 15% increase of the atmospheric moisture content. The large-scale flow is prescribed to present-day conditions. Simulations are conducted with the Europa-Modell (56 km resolution) and for the fall season, when there is preferred occurrence of heavy events over Southern Europe.
As a response to the stipulated warming the model experiments indicate a general intensification of the regional hydrological cycle with an increase of mean precipitation and evaporation similar in magnitude to the change in the atmospheric moisture content. This effect is accompanied by a pronounced increase in the occurrence of heavy precipitation.