HR: 16:10h
AN: G23A-10 INVITED     [Abstracts]
TI: Water Storage Variations from GRACE: Results and Comparisons
AU: * Swenson, S C
EM: swensosc@colorado.edu
AF: CIRES and Department of Physics, CB390 University of Colorado, Boulder, CO 80309
AB: GRACE time-variable gravity measurements are a new and innovative data type for hydrology. At approximately monthly intervals, the GRACE Project constructs a new, monthly-averaged estimate of the Earth's gravity field. Month-to-month changes in these GRACE gravity fields are primarily due to changes in the vertically-integrated water column, both on land and in the ocean. We have developed techniques that convert the GRACE gravity data into spatially-averaged water storage estimates. Applying these techniques to recently-released gravity fields, we have derived regional estimates of water storage variations for specific regions of the world. We compare these estimates to those produced by macroscale hydrologic models, as well as remotely-sensed estimates of snow water. In addition to providing direct estimates of water storage change, GRACE data can be used to estimate other components of the water cycle as residuals by combining GRACE water storage estimates with estimates of other quantities, such as precipitation and river discharge, in the appropriate water balance equation. We also compare estimates of precipitation minus evapotranspiration made using this approach to those obtained from both hydrologic models and global circulation models.
DE: 4599 General or miscellaneous
DE: 1899 General or miscellaneous
DE: 1699 General or miscellaneous
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1630 Impact phenomena
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting