HR: 14:10h
AN: GC43A-02 INVITED     [Abstracts]
TI: Recent Changes in High-Latitude Glaciers, Ice Caps, and Ice Sheets
AU: * Abdalati, W
EM: waleed@icesat2.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Oceans and Ice Branch Code 971, Greenbelt, MD 20771 United States
AB: The mass balance of high-latitude glaciers and ice sheets is highly variable on a wide range of spatial and temporal scales, but through a combination of remote sensing and in situ measurements, some significant changes have been observed in recent years. On the Greenland ice sheet most of the coastal regions have thinned substantially as melt has increased and some of its outlet glaciers have accelerated. Near the equilibrium line in West Greenland, we have seen evidence of summer acceleration that is linked to surface meltwater production, suggesting a relatively rapid response mechanism between the ice sheet and a warming climate. Throughout much of the rest of the Arctic, glaciers and ice caps have been shrinking in recent decades, with increased mass losses during the 1990s in parts of Canada and Alaska. The picture is more complicated in the southern hemisphere, where Antarctic ice is growing in some areas, shrinking dramatically in others, and is essentially in balance elsewhere. The West Antarctic Ice Sheet (WAIS) shows thinning along its northern margin, particularly in the glaciers that flow into the Amundsen Sea. The western portions of the WAIS, however, show thickening, but in the aggregate the mass loss is believed to exceed the gain. Changes in the East Antarctic Ice Sheet are small, but we don't know at this point whether it is growing or shrinking. On the Antarctic Peninsula, the rapid disintegration of the Larsen B ice shelf has resulted in acceleration and thinning of a small number of glaciers that once fed the ice shelf. This behavior raises questions about relatively near-term consequences of climate change and the Antarctic Ice Sheet's contribution to sea level rise. These recent observations offer only a snapshot in time of their long-term behavior, but they are providing crucial information about the current state of ice mass balance and the mechanisms that control it. As we continue to learn more through a combination of remote sensing observations, in situ measurements and improved modeling capabilities, it is important that we coordinate and integrate these approaches effectively in order to predict future changes and their impact on sea level.
DE: 1699 General or miscellaneous
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 1640 Remote sensing
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting