HR: 0830h
AN: C11C-0836    [PDF]
TI: Monitoring Polar Ice Change: First Results from GRACE
AU: * Velicogna, I
EM: isabella@colorado.edu
AF: CIRES & Department of Physics, CAMPUS BOX 390, University of Colorado, BOULDER,, co 80309-0390 United States
AU: Wahr, J
EM: wahr@colorado.edu
AF: CIRES & Department of Physics, CAMPUS BOX 390, University of Colorado, BOULDER,, co 80309-0390 United States
AB: The current state of ice mass imbalance in Antarctica and Greenland has significant implications for climate and global change. In this presentation, we discuss preliminary measurements of mass change in Antarctica and Greenland derived from GRACE measurements of the time-variable geoid. The measurements incorporate changes in ice mass due to combined accumulation and melting, effects of the Earth's continuing viscous response to past glacial loading, and leakage of other mass redistribution signals from adjoining regions. We compare these data with available model estimates of mass change, and we will discuss methods for combining the GRACE data with other geodetic measurements to isolate the contributions of time-variable accumulation, post glacial rebound and ice mass change. We will describe the characteristics of present-day mass imbalance and viscous rebound signals that are likely to be present in geodetic observations, and we will examine how to optimally combine time variable gravity from GRACE, altimeter measurements from ICEsat/GLAS, GPS measurements of vertical velocity, ice core measurements of compaction through time, radar-derived estimates of snow density and InSAR. We will discuss the strengths and limitations of combining different data sets.
DE: 1243 Space geodetic surveys
DE: 1645 Solid Earth
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 4556 Sea level variations
SC: Cryosphere [C]
MN: 2003 Fall Meeting