INTERNATIONAL JOURNAL OF CLIMATOLOGY Int. J. Climatol. 26: 743–769 (2006) Published online 3 February 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/joc.1280 EUROPE’S 2003 HEAT WAVE: A SATELLITE VIEW OF IMPACTS AND LAND–ATMOSPHERE FEEDBACKS BENJAMIN F. ZAITCHIK, a, * ALISON K. MACALADY, b LAURENT R. BONNEAU c and RONALD B. SMITH d a Department of Geology and Geophysics, Yale University, USA b School of Forestry and Environmental Studies, Yale University, USA c Center for Earth Observation, Yale University, USA d Department of Geology and Geophysics, Yale University, USA Received 20 March 2005 Revised 27 September 2005 Accepted 28 September 2005 ABSTRACT A combination of satellite imagery, meteorological station data, and the NCEP/NCAR reanalysis has been used to explore the spatial and temporal evolution of the 2003 heat wave in France, with focus on understanding the impacts and feedbacks at the land surface. Vegetation was severely affected across the study area, especially in a swath across central France that corresponds to the Western European Broadleaf (WEB) Forests ecological zone. The remotely sensed surface temperature anomaly was also greatest in this zone, peaking at +15.4 ° C in August. On a finer spatial scale, both the vegetation and surface temperature anomalies were greater for crops and pastures than for forested lands. The heat wave was also associated with an anomalous surface forcing of air temperature. Relative to other years in record, satellite-derived estimates of surface-sensible heat flux indicate an enhancement of 48–61% (24.0–30.5 W m −2 ) in WEB during the August heat wave maximum. Longwave radiative heating of the planetary boundary layer (PBL) was enhanced by 10.5 W m −2 in WEB for the same period. The magnitude and spatial structure of this local heating is consistent with models of the late twenty-first century climate in France, which predict a transitional climate zone that will become increasingly affected by summertime drought. Models of future climate also suggest that a soil-moisture feedback on the surface energy balance might exacerbate summertime drought, and these proposed feedback mechanisms were tested using satellite-derived heat budgets. Copyright  2006 Royal Meteorological Society. KEY WORDS: remote sensing; heatwave; drought; climate change; land–atmosphere feedback; surface energy balance 1. INTRODUCTION The European heat wave of the summer of 2003 was an extreme climatic anomaly: the mean summertime temperatures over much of western and central Europe exceeded the 1961–1990 mean by up to 5 standard deviations, and the summer might have been the warmest since 1540 (Beniston, 2004; Sch¨ ar et al., 2004). Excessive heat and/or lack of water resulted in lower yields of grains, vegetables, fruits, and wines by between 4.6 and 10.8%, with uninsured crop losses totaling about US$12.3 billion (INSEE, 2004; Sch¨ ar and Jendritzky, 2004). In France alone, officials estimated that wheat and corn harvests decreased by 15 and 28%, respectively, with losses totaling between US$1.1 and $4.4 billion (Housego, 2003). Beyond its immediate impact, the 2003 heat wave has been interpreted by many as a harbinger of long-term climate change. This interpretation is supported by simulations of future climate performed with regional climate models (RCM) forced by the IPCC B2 and A2 emission scenarios (822 and 1143 ppmv CO 2 , plus sulfate forcing, respectively). Using the Rossby Center coupled RCM (RCAO), R¨ ais¨ anen et al. (2004) predict that warming in central and southern Europe will be greatest during summer, with mean summertime * Correspondence to: Benjamin F. Zaitchik, Department of Geology and Geophysics, Yale University PO Box 208109, New Haven, CT 06520, USA; e-mail: benjamin.zaitchik@yale.edu Copyright  2006 Royal Meteorological Society