Allan and Soden: Atmospheric Warming and the Amplification of Precipitation Extremes

Science DOI: 10.1126/science.1160787; published online August 7, 2008

Reports

Submitted on May 21, 2008; Accepted on July 29, 2008

Atmospheric Warming and the Amplification of Precipitation Extremes

Richard P. Allan ^1* and Brian J. Soden ²

¹ Environmental Systems Science Centre, University of Reading, Berkshire, RG6 6AL, U.K.
² Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, FL 33149, U.S.A.

^* To whom correspondence should be addressed.
Richard P. Allan , e-mail: r.p.allan@reading.ac.uk

Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. However, observational limitations have hindered a direct evaluation of model projected changes in extreme precipitation. Here, we use satellite observations and model simulations to examine the response of tropical precipitation events to naturally driven changes in surface temperature and atmospheric moisture content. These observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than predicted by models, implying that projections of future changes in rainfall extremes due to anthropogenic global warming may be underestimated.

Link to abstract: http://www.sciencemag.org/cgi/content/abstract/1160787