European wind storms, related loss potentials and changes in multi-model climate simulations

• Main Author: Donat, Markus G.
• Other Authors: [e-mail], m, Prof. Dr. U. Ulbrich, Prof. Dr. U. Cubasch
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2010
• Subjects: European wind storm; storm losses; climate change; multi-model climate; ddc:551; Pacific; North Atlantic
• Online Access: https://refubium.fu-berlin.de/handle/fub188/6190; https://doi.org/10.17169/refubium-10389; https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000017979-3

The occurrence of European winter storms and consequential losses is examined on the basis of reanalysis data and multi-model climate simulations, with the aim of learning about potential future changes of wind storm risk in Europe. Considering multi-model simulations conduces to an estimation of the (un-) certainties of change signals. Characteristics of the large-scale atmospheric flow are analysed and examined in conjunction with the occurrence of wind storms in Central Europe. Additionally, extreme wind speeds and the related loss potentials are investigated, applying a loss regression model. Further, the effect of dynamical downscaling on the results is considered with respect to extreme wind and storm loss analysis, and the benefit of combining different climate models to a multi-model ensemble is examined. Validating the climate model simulations of the recent climate against ERA40-reanalysis data leads to the finding that the models are generally capable of reproducing observed characteristics of atmospheric circulation and wind storm related atmospheric features in the North Atlantic / European region. One limitation, however, is a tendency towards an excess of zonal flow situations and an underestimation of anticyclonic flow in most models. In future climate scenario simulations, a significantly reduced total number of extra-tropical cyclones is found in the northern hemisphere, whereas considering only extreme cyclones, hotspots of increased activity are found over the eastern parts of the North Atlantic and the North Pacific. Focussing on Central Europe, the large-scale atmospheric flow is characterised by an increased frequency of westerly flow situations, and also an enhanced frequency of storm days is analysed, in ensemble mean between 19 and 33 % for two different measures of storminess. The intensity of cyclones associated with wind storm in Central Europe is increased by about 10 % in ensemble mean in the Eastern Atlantic and in the North Sea. Furthermore, the wind speeds during storm events ...