Code 614.4 Branch Seminar

Ben Zaitchik, Yale University

Abstract Two brief but intense droughts of the past decade are considered: Western Europe in the summer of 2003 and the Middle East in the spring of 1999. Each event had a dramatic impact on vegetation and surface hydrology, establishing the potential for land-atmosphere feedbacks on temperature and/or precipitation. Impacts, forcings, and feedbacks during the two droughts are explored using satellite data and a regional climate model. It is found that the effects of these droughts differed substantially, reflecting differences in regional context and event meteorology. In Europe, surface drought led to a positive forcing on air temperature and, perhaps, a reduction in the potential for convective precipitation. In contrast, surface drought in the Middle East was associated with a negative forcing on air temperature. The surface forcing on cloudiness and convective potential was negative, as it was in Europe, but the mechanism relied on increased albedo rather than enhanced sensible heat flux. Short bio-sketch of the presenter: Ben Zaitchik received a B.A. in biology from Harvard College in 1998 and an M.S. in soil science from Cornell University in 2001. He is currently completing his Ph.D. in the department of Geology and Geophysics at Yale University, with research on land-atmosphere interactions in water-stressed regions.