HR: 1340h
AN: A53B-0894    [Abstracts]
TI: Glacier Recession on Kilimanjaro and Associated Changes in Regional Climate and Tropical Atmospheric Circulation
AU: Moelg, T
EM: thomas.moelg@uibk.ac.at
AF: Tropical Glaciology Group, Department of Geography, University of Innsbruck, Innrain 52, Innsbruck, 6020 Austria
AU: Cullen, N J
EM: nicolas.cullen@uibk.ac.at
AF: Tropical Glaciology Group, Department of Geography, University of Innsbruck, Innrain 52, Innsbruck, 6020 Austria
AU: Gohm, A
EM: alexander.gohm@uibk.ac.at
AF: Mountain Meteorology Group, Institute of Meteorology, University of Innsbruck, Innrain 52, Innsbruck, 6020 Austria
AU: Hardy, D R
EM: dhardy@geo.umass.edu
AF: Climate System Research Center, Department of Geosciences, University of Massachusetts, 611 North Pleasant Street, Amherst, MA 01003-9297 United States
AU: * Kaser, G
EM: georg.kaser@uibk.ac.at
AF: Tropical Glaciology Group, Department of Geography, University of Innsbruck, Innrain 52, Innsbruck, 6020 Austria
AU: Mayr, G
EM: georg.mayr@uibk.ac.at
AF: Mountain Meteorology Group, Institute of Meteorology, University of Innsbruck, Innrain 52, Innsbruck, 6020 Austria
AB: The significance of tropical glaciers as climate proxy data has been steadily increasing in recent years, since they are essential for the detection of high-altitude, regional climate change. As with tropical glaciers worldwide, the famous glaciers on Kilimanjaro have been retreating continuously over the past century, with the onset of retreat around 1880. Due to peculiar features of this distinct volcano (physiogeographical setting, glacier shape and dynamics), our research concept for investigating glacier retreat proposes the definition of at least three different glacier regimes. Current investigations on these glacier regimes by energy and mass balance models, based on data from the University of Massachusetts automatic weather station on a plateau glacier, indicate that Kilimanjaro glaciers are most sensitive to changes in moisture-related climate variables like cloudiness, incoming shortwave radiation, precipitation and surface albedo, and that such changes due to a drier climate control the present glacier retreat. One essential question therefore arises. Under what climatic conditions has enough precipitation occurred on top of Kilimanjaro to enable the formation and maintenance of glaciers? Our results to date are in good accordance with other climate proxy data (e.g., lake levels, circulation indices), as these also indicate an abrupt drop in atmospheric moisture over East Africa in the late 19th century. Since East African precipitation amounts are strongly tied to sea surface temperature (SST) anomalies in the Indian Ocean, the key for understanding glacier retreat on Kilimanjaro might most probably be found in changes of the larger-scale (mesoscale) atmospheric circulation and related SST patterns, rather than in changes of local Kilimanjaro climate only. To meet the required research at different climatological scales, micrometeorological measurements over the glaciers and related modeling (see above) are complemented by studies with a numerical atmospheric model, to simulate changes in the mesoscale circulation over the Indian Ocean-East Africa region.
DE: 3307 Boundary layer processes
DE: 1827 Glaciology (1863)
DE: 1620 Climate dynamics (3309)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting