HR: 1340h
AN: GC33A-0957    [Abstracts]
TI: Climate-Vegetation-Feedbacks as a Mechanism for Accelerated Climate Change: The Greening Sahara Case
AU: * Timm, O
EM: timm@hawaii.edu
AF: IPRC, SOEST, University of Hawaii at Manoa, 1680 East West Road, POST Bldg 413J, Honolulu, HI 96822, United States
AU: Koehler, P
EM: Peter.Koehler@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, PO Box 120161, Bremerhaven, D-27515, Germany
AU: Timmermann, A
EM: axel@hawaii.edu
AF: IPRC, SOEST, University of Hawaii at Manoa, 1680 East West Road, POST Bldg 413G, Honolulu, HI 96822, United States
AB: In a set of experiments with global atmosphere-ocean-vegetation models, we analyze the terrestrial vegetation history from the Last Glacial Maximum to the pre-industrial time. In this presentation we explore the mechanisms in the coupled atmosphere-ocean-vegetation system that initiate the migration of the African Monsoon rainfall into the Sahara and the subsequent greening of the Sahara. It is found that the vegetation-albedo-feedback is of crucial importance for the northward extension of the vegetation zone into the Sahara desert. This feedback leads to an amplified response of the African Monsoon to the orbital forcing in the early Holocene. We further discuss the changes in the terrestrial carbon storage and its implications for atmospheric CO₂ concentrations. A preliminary comparison between model results and paleoproxy records is presented.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4910 Astronomical forcing
DE: 4928 Global climate models (1626, 3337)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting