HR: 0830h
AN: B51E-1020    [PDF]
TI: Role of global oceanic forcing and local vegetation feedback in the 20th century Sahel drought: results from the coupled GENESIS-IBIS model
AU: * Wang, G
EM: gwang@engr.uconn.edu
AF: University of Connecticut, Department of Civil & Environmental Engineering, Storrs, CT 06269
AU: Eltahir, E A
EM: eltahir@mit.edu
AF: Massachusetts Institute of Technology, Department of Civil & Environmental Engineering, Cambridge, MA 02139
AU: Foley, J A
EM: jfoley@wisc.edu
AF: University of Wisconsin-Madison, Center for Sustainability and Global Environment, Madison, WI 53726
AU: Pollard, D
EM: pollard@essc.psu.edu
AF: Pennsylvania State University, EMS Environment Institute, University Park, PA 16802
AU: Levis, S
EM: slevis@ucar.edu
AF: National Center for Atmospheric Research, Terrestrial Science Section, Boulder, CO 80307
AB: Previous studies have indicated that both large-scale forcing from the ocean and land surface feedback may have contributed to the severe drought in the 20th century over the Sahel region. In this study we investigate the role of these two factors in the variability of the Sahel rainfall using a sophisticated global biosphere-atmosphere model GENESIS-IBIS. The observed global sea surface temperature in the 20th century are used as as the model driving forcing. Using this coupled global model, we experiment on treating vegetation as a static boundary condition and as a dynamic component of the earth climate system. Our results indicate that the global oceanic forcing can cause a severe drought in the simulated climate system with vegetation being a dynamic component. However, the 20th century Sahel drought may not have occurred if the vegetation were kept as static. Our study emphasizes the important role of dynamic vegetation in regulating the rainfall variability over the Sahel region, and confirms some previous findings from less sophisticated models.
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting