Academic Commons

Articles

Enhanced spring convective barrier for monsoons in a warmer world?

Seth, Anji; Rauscher, Sara A.; Rojas, Maisa; Giannini, Alessandra; Camargo, Suzana J.

Twenty-first century climate model projections show an amplification of the annual cycle in tropical precipitation with increased strength in both wet and dry seasons, but uncertainty is large and few studies have examined transition seasons. Here we analyze coupled climate model projections of global land monsoons and show a redistribution of precipitation from spring to summer in northern (North America, West Africa and Southeast Asia) and southern (South America, Southern Africa) regions. The annual cycle changes are global in scale. Two mechanisms, remote (based on tropospheric stability) and local (based on low level and surface moisture), are evaluated through the annual cycle. Increases in tropospheric stability persist from winter into spring and are reinforced by a reduction in surface moisture conditions, suggesting that in spring both remote and local mechanisms act to inhibit convection. This enhanced spring convective barrier leads to reduced early season rainfall; however, once sufficient increases in moisture (by transport) are achieved, decreases in tropospheric stability result in increased precipitation during the late rainy season. Further examination of this mechanism is needed in observations and models, as the projected changes would have substantial implications for agriculture, water management, and disaster preparedness.

Subjects

Files

  • thumnail for seth_rauscher_rojas_giannini_camargo_climatic_change11.pdf seth_rauscher_rojas_giannini_camargo_climatic_change11.pdf application/x-pdf 1.75 MB Download File

Also Published In

Title
Climatic Change
DOI
https://doi.org/10.1007/s10584-010-9973-8

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
International Research Institute for Climate and Society
Publisher
Springer
Published Here
June 2, 2015
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.