HR: 17:15h
AN: GC24A-05    [Abstracts]
TI: Consistency of Observed Northern European Precipitation and Temperature Trends With Regional Climate Change Projections
AU: * Bhend, J
EM: jonas.bhend@gkss.de
AF: Institute for Coastal Research, GKSS Research Center, Max-Planck-Strasse 1, Geessthacht, 21502, Germany
AU: * Bhend, J
EM: jonas.bhend@gkss.de
AF: International Max Planck Research School on Earth System Modelling, Bundesstrasse 53, Hamburg, 20146, Germany
AU: von Storch, H
EM: hvonstorch@web.de
AF: Institute for Coastal Research, GKSS Research Center, Max-Planck-Strasse 1, Geessthacht, 21502, Germany
AU: von Storch, H
EM: hvonstorch@web.de
AF: Meteorological Institute, University of Hamburg, Bundesstrasse 55, Hamburg, 20146, Germany
AB: Often it is claimed that recent changes in northern European climate are at least partly anthropogenic even though a human influence has not yet been successfully detected. Increasing variability with decreasing scale of aggregation (and thus in general decreasing signal-to-noise ratios) as well as limitations in the ability of present day climate models in simulating the regional climate are main factors complicating successful detection and attribution at the regional scale. Hence, we choose a different approach and investigate whether the recent changes are consistent with regional climate change projections. In this study, we use gridded seasonal precipitation totals and seasonal mean temperature in the Baltic catchment, which are compared with anthropogenic climate change signals, derived from a set of different regional climate model simulations. The observed patterns of change for precipitation in winter (DJF) and spring (MAM) are consistent with model expectations. However, the model projections generally underestimate the recent change in precipitation. In summer (JJA) and fall (SON) we do not find consistency between the observed and expected patterns of change. In contrast, the patterns of change in temperature are found to be consistent with model expectations in all seasons, and the magnitude of the change is comparable as well. European trends contain large NAO-related signals, of which a major unknown part may be unrelated to the anthropogenic signal. Therefore, we also examine the consistency of recent and projected changes after subtracting the NAO signal in both the observations and in the projections. The results for precipitation in winter and spring are robust to the removal of the NAO signal, whereas considerably lower pattern similarity is found for temperature in the respective seasons. Furthermore, after removing the NAO signal from the data, trends in winter and spring temperature are considerably reduced and thus lower than the respective anthropogenic change estimates.
DE: 1637 Regional climate change
DE: 1655 Water cycles (1836)
DE: 1854 Precipitation (3354)
DE: 3355 Regional modeling
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting