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Mass Gains of the Antarctic Ice Sheet Exceed LossesDuring 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt/yr (2.5% of input), as derived from ICESat laser measurements of elevation change. The net gain (86 Gt/yr) over the West Antarctic (WA) and East Antarctic ice sheets (WA and EA) is essentially unchanged from revised results for 1992 to 2001 from ERS radar altimetry. Imbalances in individual drainage systems (DS) are large (-68% to +103% of input), as are temporal changes (-39% to +44%). The recent 90 Gt/yr loss from three DS (Pine Island, Thwaites-Smith, and Marie-Bryd Coast) of WA exceeds the earlier 61 Gt/yr loss, consistent with reports of accelerating ice flow and dynamic thinning. Similarly, the recent 24 Gt/yr loss from three DS in the Antarctic Peninsula (AP) is consistent with glacier accelerations following breakup of the Larsen B and other ice shelves. In contrast, net increases in the five other DS of WA and AP and three of the 16 DS in East Antarctica (EA) exceed the increased losses. Alternate interpretations of the mass changes driven by accumulation variations are given using results from atmospheric-model re-analysis and a parameterization based on 5% change in accumulation per degree of observed surface temperature change. A slow increase in snowfall with climate waRMing, consistent with model predictions, may be offsetting increased dynamic losses.
Document ID
20120013495
Document Type
Conference Paper
Authors
Zwally, H. Jay (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Li, Jun (SGT, Inc. Greenbelt , MD, United States)
Robbins, John (Science Systems and Applications, Inc. Greenbelt, MD, United States)
Saba, Jack L. (Science Systems and Applications, Inc. Greenbelt, MD, United States)
Yi, Donghui (SGT, Inc. Greenbelt , MD, United States)
Brenner, Anita (Sigma Space Corp. Greenbelt, MD, United States)
Bromwich, David
Date Acquired
August 26, 2013
Publication Date
July 14, 2012
Subject Category
Meteorology and Climatology
Report/Patent Number
GSFC.ABS.6573.2012
Meeting Information
ISMASS (Ice-Sheet Mass Balance and Sea Level) Workshop of SCAR Scientific Committee on Antarctic Research(Portland, OR)
Distribution Limits
Public
Copyright
Public Use Permitted.

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