HR: 0800h
AN: GC51A-1050    [Abstracts]
TI: Impacts of Recent Warming on a Floating Ice Tongue in Northern Greenland
AU: * Cullen, N J
EM: cullenn@cires.colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, CB 216, University of Colorado, Boulder, CO 80309 United States
AU: Huff, R
EM: russell.huff@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, CB 216, University of Colorado, Boulder, CO 80309 United States
AU: Steffen, K
EM: konrad.steffen@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, CB 216, University of Colorado, Boulder, CO 80309 United States
AU: Rignot, E
EM: ericrignot@jpl.nasa.gov
AF: Jet Propulsion Laboratory, Mail Stop 300-235, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: The recent collapse of ice shelves in West Antarctica and to the Ward Hunt Ice Shelf, Ellesmere Island, Canada, has been interpreted as evidence of accelerated climate change in the high latitudes. To improve our understanding of the stability of glaciers in northern Greenland a combination of field data, remote sensing observations and modeling is used to investigate both bottom and surface melt processes on the Petermann Gletscher (81 N, 60 W). The Petermann Gletscher is similar to other more well-known ice shelves because it has a large floating section, or ice tongue, that is 20-km wide by 70-km long. This purpose of this work is to describe in detail the surface climate of the Petermann Gletscher from automatic weather station (AWS) data. Emphasis in placed on describing surface energy exchanges that have controlled ablation over the 3 most recent summer seasons (2002-4). Projection of ablation over the entire surface of the ice tongue using a degree-day model shows that surface lowering of the ice tongue in 2002-3 is 50 percent higher than a 53-year proxy melt record established from AWS measurements at nearby Alert, Ellesmere Island. If this warming trend continues the increased thinning rate is likely to yield enhanced calving rates at the ice front of the Petermann Gletscher, which could ultimately weaken and fracture the floating ice tongue.
DE: 9315 Arctic region
DE: 3349 Polar meteorology
DE: 4215 Climate and interannual variability (3309)
DE: 1827 Glaciology (1863)
DE: 1610 Atmosphere (0315, 0325)
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting