Geophys. Res. Lett., in press.

Delayed Sahel rainfall and global seasonal cycle in a warmer climate

Michela Biasutti
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY

Adam H. Sobel
Department of Applied Physics and Applied Mathematics and Department of Earth and Environmental Sciences, Columbia University, New York, NY.


21st century projections of global rainfall and sea surface temperature in the current generation of climate models indicate a delay in the seasonal cycle in response to increasing greenhouse gases, with important implications for the regional monsoons. In particular, the rainy season of the semi-arid African Sahel is projected to start later and become shorter. The robust agreement across models on the seasonal distribution of Sahel rainfall changes stands in contrast with large uncertainty for summertime rainfall totals there.