Future regional projections of extreme temperatures in Europe: a nonstationary seasonal approach

This paper analyzes changes of maximum temperatures in Europe, which are evaluated using two state-of-the-art regional climate models from the EU ENSEMBLES project. Extremes are expressed in terms of return values using a time-dependent generalized extreme value (GEV) model fitted to monthly maxima. Unlike the standard GEV method, this approach allows analyzing return periods at different time scales (monthly, seasonal, annual, etc). The study focuses on the end of the 20th century (1961-2000), used as a calibration/validation period, and assesses the changes projected for the period 2061-2100 considering the A1B emission scenario. The performance of the regional models is evaluated for each season of the calibration period against the high-resolution gridded E-OBS dataset, showing a similar South-North gradient with larger values over the Mediterranean basin. The inter-RCM changes in the bias pattern with respect to the E-OBS are larger than the bias resulting from a change in the boundary conditions from ERA-40 to ECHAM5 20c3m. The maximum temperature response to increased green house gases, as projected by the A1B scenario, is consistent for both RCMs. Under that scenario, results indicate that the increments for extremes (e. g. 40-year return values) will be two or three times higher than those for the mean seasonal temperatures, particularly during Spring and Summer in Southern Europe. © 2011 Springer Science+Business Media B.V.The ENSEMBLES data used in this work was funded by the EU FP6 Integrated Project ENSEMBLES (Contract number 505539) whose support is gratefully acknowledged. We acknowledge the E-OBS data set and the data providers in the ECA&D project (http://eca.knmi.nl). R. Mínguez is indebted to the Spanish Ministry MICINN for the funding provided within the “Ramón y Cajal” program. This work was partly funded by projects “GRACCIE” (CSD2007-00067, Programa Consolider-Ingenio 2010), “AMVAR” (CTM2010-15009) and EXTREMBLES (CGL2010-21869) from Spanish Ministry MICINN, by project C3E (200800050084091) and ESCENA (200800050084265) from the Spanish Ministry MARM, and by project MARUCA (E17/08) from the Spanish Ministry MF.Peer Reviewe