HR: 09:45h
AN: GC31C-08    [Abstracts]
TI: Climate Change in Tropical East Africa: Combining High-Altitude Measurements, Proxy Records and Numerical Modeling
AU: * Moelg, T
EM: thomas.moelg@uibk.ac.at
AF: Department of Earth and Atmospheric Sciences, University of Innsbruck, Innrain 52, Innsbruck, 6020, Austria
AU: * Moelg, T
EM: thomas.moelg@uibk.ac.at
AF: Department of Geography and Center for Atmospheric Sciences, University of California at Berkeley, 507 McCone Hall, Berkeley, CA 94720-4740, United States
AU: Cullen, N J
EM: njc@geography.otago.ac.nz
AF: Department of Geography, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
AU: Hardy, D R
EM: dhardy@geo.umass.edu
AF: Department of Geosciences, University of Massachusetts, Morrill Science Center, Amherst, MA 01003-9297, United States
AU: Kaser, G
EM: georg.kaser@uibk.ac.at
AF: Department of Earth and Atmospheric Sciences, University of Innsbruck, Innrain 52, Innsbruck, 6020, Austria
AB: Several types of proxy data indicate a rapid climate change in tropical East Africa around 1880, leading from wet to relatively dry conditions. The change manifested itself in the drop of lake levels, alteration of limnological sediment composition, and - at high altitude - glacier recession. To understand these changes, we run an extensive field program on the glaciers in the vicinity of Kilimanjaro summit (5895 m a.s.l.). Application of the field data to a glacier mass balance model, which resolves the physics of the glacier-climate interaction, allows the derivation of former glacier extents and thus local climate conditions of the pre-1880 wet period. From the latter we can deduce the magnitude of changes in precipitation, air temperature, air humidity, and solar radiation in the mid-troposphere. To explore the potential value of upscaling from regional to large-scale tropical climate change, a 200-year paleoclimate simulation with the Community Climate System Model (CCSM 3.0) is analyzed. Results suggest that changes in Indian Ocean dynamics (atmosphere-ocean interactions), and related moisture transport into East Africa, most likely contributed to this rapid regional climate change.
DE: 0776 Glaciology (1621, 1827, 1863)
DE: 0798 Modeling
DE: 1620 Climate dynamics (0429, 3309)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting