HR: 08:00h
AN: C41A-01    [PDF]
TI: STABILITY OF ANTARCTIC ICE SHELVES AND THEIR ROLE IN THE GLOBAL CLIMATE SYSTEM
AU: * Lange, M A
EM: langema@uni-muenster.de
AF: Institute for Geophysics, University of Muenster, Corrensstr. 24, Muenster, D-48149 Germany
AU: Grosfeld, K
EM: grosfeld@palmod.uni-bremen.de
AF: Department of Geosciences/MARUM, University of Bremen, Postfach 330 440, Bremen, D-28334 Germany
AU: MacAyeal, D R
EM: drm7@midway.uchicago.edu
AF: Department of Geophysical Sciences, University of Chicago, 5734 S. Ellis Ave., Chicago, IL IL 60637 United States
AU: Saheicha, K
EM: saheicha@earth.uni-muenster.de
AF: Institute for Geophysics, University of Muenster, Corrensstr. 24, Muenster, D-48149 Germany
AB: The Earth's radiation budget, a key determinant of global climate, depends critically on the spatial distribution of surface albedos of our planet. Climate is also driven by major oceanic transport and exchange processes. In that regard, the polar regions play a particularly decisive role. While attention has so far mainly been paid to the annual and inter-annual variability of polar sea ice covers, a number of recent dramatic changes, i.e., the disintegration of the Larsen A- and parts of Larsen B Ice Shelves as well as the major calving events of Filchner-Ronne- and Ross Ice Shelves have led to renewed interest in the role of ice shelves for the global climate system. In this regard, it is not only the disintegration of ice shelves itself that is of particular concern. Ice shelves are known to play a distinct role in the overall stability of the (West-) Antarctic Ice Sheet. Thus, ice shelf disintegration could lead to instability of (parts of) the Antarctic ice cover, with corresponding consequences for the global albedo. Furthermore, the disintegration of major ice shelves will ultimately lead to a significant change of Antarctic Bottom Water (AABW) formation with widespread implications for the world ocean and ultimately global climate. In this paper we will, firstly based on a conceptual model, elucidate the possible impact chain leading from initial regional climate warming, over surface processes on the ice shelves and an increase in calving events to their possible disintegration. We will strive to consider possible feedback between reduced ice shelf surface area and sub-ice shelf exchange processes and their role for global climate and AABW formation. The more qualitative conjectures will be compared with first results from coupled ice shelf-ocean models under varying climate conditions.
UR: http://earth.uni-muenster.de/projekte/clivar.html
DE: 1630 Impact phenomena
DE: 1863 Snow and ice (1827)
DE: 4207 Arctic and Antarctic oceanography
SC: Cryosphere [C]
MN: 2003 Fall Meeting