HR: 11:35h
AN: C32A-05    [Abstracts]
TI: Snow Accumulation, Ice Discharge and Mass Balance in Greenland and Antarctica from GRACE
AU: * Velicogna, I
EM: isabella@colorado.edu
AF: Dept of Physics and CIRES, UCB 390, U. of Colorado,, Boulder, CO 80309-0390 United States
AU: Wahr, J
EM: wahr@colorado.edu
AF: Dept of Physics and CIRES, UCB 390, U. of Colorado,, Boulder, CO 80309-0390 United States
AU: Hanna, E
EM: ehanna@sheffield.ac.uk
AF: U. of Sheffield, Winter Street, Sheffield, S10 2TN United Kingdom
AU: Huybrechts, p
EM: phuybrec@vub.ac.be
AF: U. of Brussels,, Pleinlaan 2, Brussels, B-105 Belgium
AB: The GRACE satellite mission, launched in March of 2002, provides monthly measurements of time variable gravity at scales of a few hundred kilometers and larger. These data can be used to estimate temporal variations in the distribution of surface mass. We examine here the nineteen monthly GRACE gravity field solutions that are currently available for analyses. We find that these fields can be used to recover mass imbalance and net snow accumulation for the Greenland and Antarctic ice sheets. GRACE estimates of Greenland mass change agree with ice mass imbalance estimates from altimeter heights within measurement errors. We also estimate net snow accumulation from the nonsecular component of the GRACE signal. If precipitation minus evapo-transpiration (P-E) and runoff (R) are known it is possible to obtain monthly estimates of ice discharge through the grounding line from GRACE. We estimate ice discharge for the Greenland ice sheet by combining GRACE estimates of nonsecular net snow accumulation with ERA40-derived P-E-R.
DE: 4556 Sea level variations
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 1243 Space geodetic surveys
DE: 1645 Solid Earth
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting