HR: 14:25h
AN: G23A-04    [Abstracts]
TI: Time-Variable Gravity From Satellite Laser Ranging and Doppler Measurements: A look at the interannual and annual variations and comparison with GRACE results
AU: * Cox, C M
EM: ccox@bowie.gsfc.nasa.gov
AF: Raytheon ITSS Space Geodesy Branch, NASA Goddard Space Flight Center Mailstop 926.0, Greenbelt, MD 20771 United States
AU: Lemoine, F G
EM: flemoine@bowie.gsfc.nasa.gov
AF: Space Geodesy Branch, NASA Goddard Space Flight Center Mailstop 926.0, Greenbelt, MD 20771 United States
AU: Luthcke, S B
EM: sluthcke@bowie.gsfc.nasa.gov
AF: Space Geodesy Branch, NASA Goddard Space Flight Center Mailstop 926.0, Greenbelt, MD 20771 United States
AU: Rowlands, D D
EM: drowland@bowie.gsfc.nasa.gov
AF: Space Geodesy Branch, NASA Goddard Space Flight Center Mailstop 926.0, Greenbelt, MD 20771 United States
AU: Chao, B F
EM: chao@bowie.gsfc.nasa.gov
AF: Space Geodesy Branch, NASA Goddard Space Flight Center Mailstop 926.0, Greenbelt, MD 20771 United States
AB: Satellite Laser Ranging (SLR) derived long wavelength gravity time series analysis has focused principally on the effects of the recent large changes in the Earth's zonals, particularily J2, or the long-term secular rates, and the potential causes. However, it is also possible to estimate the shorter wavelength coefficients, including non-zonals, over monthly time scales, and to connect these with known geophysical signals. While the formal uncertainty of these terms is significantly higher than that for J2, it is also clear that there is useful signal to be extracted. We will present updates on recent gravity field variations, including the J2 evolution, as well as other components of the interannual variations of the gravity field and geophysical and climatic connections. These results will also be compared to data from the GRACE mission, which provides an independent means of assessing the SLR and Doppler derived time series. Work is presently in progress to process the SLR and GRACE data using a common set of background models within GEODYN to allow a more complete assessment. Initial comparisons have shown reasonable agreement in terms of annual and semiannual variations, as well as some component time series, such as the C2,1 and S2,1 terms.
DE: 1655 Water cycles (1836)
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1234 Regional and global gravity anomalies and Earth structure
DE: 1645 Solid Earth
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting