CR 44:167-177 (2010)  -  doi:10.3354/cr00973

Validation of temperature trends in the ENSEMBLES regional climate model runs driven by ERA40

Philip Lorenz1,2,*, Daniela Jacob

1Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
2Present address: Institute of Meteorology, Freie Universität Berlin, Carl-Heinrich-Becker-Weg 6–10, 12165 Berlin, Germany

ABSTRACT: In the EU-Project ENSEMBLES, a major objective was the development of a weighting system for regional climate models (RCMs) based on the ability of the RCMs to reproduce observed characteristics of important atmospheric variables. Within this context, a suite of state-of-the-art RCMs was employed for the creation of probabilistic future regional climate change scenarios for Europe. Among others, one measure to determine the individual RCM-weights is their ability to reproduce the observed trends in 2 m temperature in the reanalysis (ERA40)-driven experiments for the period 1960–2000. As the reference, we used the new ENSEMBLES observational gridded dataset for Europe (E-OBS). As additional datasets for comparisons, we also used the near-surface temperature datasets from the CRU observations and from the ERA40 and NCEP/NCAR reanalysis. The analysis was performed for the land fraction of 8 different European regions, the so-called PRUDENCE regions defined within the PRUDENCE project (http://prudence.dmi.dk). Annual and seasonal linear trends in near-surface temperature were computed for each ENSEMBLES RCM, the E-OBS dataset, and for the additional datasets mentioned above. In all regions, the computed linear temperature trends based on annual mean temperatures showed