HR: 10:35h
AN: G32A-02    [Abstracts]
TI: Glacial isostatic adjustment on the Northern Hemisphere - new results from GRACE
AU: * Mueller, J
EM: mueller@ife.uni-hannover.de
AF: University of Hannover Institute of Geodesy, Schneiderberg 50, Hannover, 30167, Germany
AU: Steffen, H
EM: steffen@ife.uni-hannover.de
AF: University of Hannover Institute of Geodesy, Schneiderberg 50, Hannover, 30167, Germany
AU: Gitlein, O
EM: gitlein@ife.uni-hannover.de
AF: University of Hannover Institute of Geodesy, Schneiderberg 50, Hannover, 30167, Germany
AU: Denker, H
EM: denker@ife.uni-hannover.de
AF: University of Hannover Institute of Geodesy, Schneiderberg 50, Hannover, 30167, Germany
AU: Timmen, L
EM: timmen@ife.uni-hannover.de
AF: University of Hannover Institute of Geodesy, Schneiderberg 50, Hannover, 30167, Germany
AB: The Earth's gravity field mapped by the Gravity Recovery and Climate Experiment (GRACE) satellite mission shows variations due to the integral effect of mass variations in the atmosphere, hydrosphere and geosphere. The Earth's gravity field is provided in form of monthly solutions by several institutions, e.~g. GFZ Potsdam, CSR and JPL. During the GRACE standard processing of these analysis centers, oceanic and atmospheric contributions as well as tidal effects are reduced. The solutions of the analysis centers differ slightly, which is due the application of different reduction models and center-specific processing schemes. We present our investigation of mass variations in the areas of glacial isostatic adjustment (GIA) in North America and Northern Europe from GRACE data. One key issue is the separation of GIA parts and the reduction of the observed quantities by applying dedicated filters (e.~g. isotropic, non-isotropic, and destriping filters) and global models of hydrological variations (e.~g. WGHM, LaDWorld, GLDAS). In a further step, we analyze the results of both regions regarding their reliability, and finally present a comparison to results of a geodynamical modeling and absolute gravity measurements. Our results clearly show that the quality of the GRACE-derived gravity- change signal benefits from improved reduction models and chosen analysis techniques. Nevertheless, the comparison to results of geodynamic models still reveals differences, and thus further studies are in progress.
DE: 1218 Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532)
DE: 1222 Ocean monitoring with geodetic techniques (1225, 1641, 3010, 4532, 4556, 4560, 6959)
DE: 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions (0762, 1218, 3319, 4550)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1295 Integrations of techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting