The exceptionally hot summer of 2007 in Athens, Greece - A typical summer in the future climate?

Summer 2007 was abnormally warm for many areas of southeastern Europe, the Balkan peninsula and parts of Asia Minor with departures from the seasonal means exceeding 4 degrees C in some areas but also distinct periods of extremely hot weather. Greece experienced very likely the warmest summer of its instrumental history with record breaking temperatures being observed at a number of stations. The historical air temperature record of the National Observatory of Athens (NOA), extending back to the 19th century, was used in order to highlight the rarity of the event. Seasonal (June to August) temperature anomalies at NOA exceeded 3 degrees C corresponding to more than 3 standard deviations with respect to the 1961-1990 reference period. The record value of 44.8 degrees C was observed at NOA on 26 June 2007 (previous record 43 degrees C in June 1916) during the first and most intense heat wave that affected the area. The study places summer 2007 in the climatology of the previous century and also examines whether the statistics of summer 2007 have similarities with Mediterranean summers of the future. An ensemble of regional climate model simulations undertaken for the European domain indicate that summer 2007 reflects the daily maximum temperatures that are projected to occur in the latter part of the 21st century. The analysis of temperature data from other less urbanized stations indicates that the urban heat effect in Athens contributed positively to the anomalies of the nocturnal temperatures. The abnormally hot summer of 2007 is perhaps not the proof but a strong indicator of what eastern Mediterranean summers could resemble in future. (C) 2009 Elsevier B.V. All rights reserved.