HR: 0830h
AN: C31C-0410    [PDF]
TI: About the Freshwater Contribution of the Eastern Weddell Ice Shelves to Water Mass Formation in the Weddell Sea
AU: * Thoma, M
EM: thoma@uni-muenster.de
AF: Institute for Geophysics, University of M\"unster, Corrensstr.24, M\"unster, 48149 Germany
AU: Grosfeld, K
EM: grosfeld@palmod.uni-bremen.de
AF: Department of Geosciences/MARUM University of Bremen, Postfach 330 440, Bremen, 28334 Germany
AU: Lange, M A
EM: langema@uni-muenster.de
AF: Institute for Geophysics, University of M\"unster, Corrensstr.24, M\"unster, 48149 Germany
AB: The interface between the Antarctic Ice Sheet and the Southern Ocean corresponds to the bases of floating ice shelves which constitute about one half of Antarctica's coast line. Heat and mass fluxes across this interface, associated with melting and freezing processes, directly affect the ice shelf glacial system. Furthermore, modifications of dense water masses due to melting and freezing at the ice shelf base is directly linked to the formation of deep waters at the continental shelf break. Hence, the export of Ice Shelf Water (ISW) from the extensive ice shelf cavities, especially in the Weddell- and Ross Seas, represents an important component for the ventilation of the world ocean abyss. However, the smaller ice shelf regions in the Weddell Sea, the Larsen and the Eastern Weddell Ice Shelves (EWIS) represent important contributors to this process. Their role in this discussion is up to now possibly underestimated. In this study we concentrate on the eastern Weddell Sea sector as an important inflow region for the subsequent following upstream regions, the Filchner Ronne Ice Shelf and the Larsen Ice Shelf. Applying a three dimensional ocean model with as realistic as possible bathymetry and ice thickness data based on the BEDMAP data set, we simulated the flow regime in this region and calculate the freshwater flux, formed at the base of the ice shelf. Our analysis will lead to sensitivity studies for the influence of increased ocean temperatures, possibly caused by global warming and different ice shelf--ocean boundary conditions, affecting the melting and freezing rates. EWIS is of special interest, as it is separated from the coastal current by a narrow continental shelf margin and partly overlaps the deep sea. Hence, direct interaction of the coastal current with the ice shelf is expected to lead to high melting rates.
DE: 1635 Oceans (4203)
DE: 4215 Climate and interannual variability (3309)
DE: 4255 Numerical modeling
DE: 4283 Water masses
SC: Cryosphere [C]
MN: 2003 Fall Meeting