HR: 12:05h
AN: G22A-08    [Abstracts]
TI: Surface Mass Variations From GPS/Ocean Bottom Pressure Model and GRACE
AU: * Wu, X
EM: Xiaoping.Wu@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 238-600, Pasadena, CA 91109 United States
AU: Heflin, M B
EM: mbh@mail.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 238-600, Pasadena, CA 91109 United States
AU: Ivins, E R
EM: eri@fryxell.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 238-600, Pasadena, CA 91109 United States
AB: We study seasonal surface mass variations and the resulting load-induced deformation as well as time-variable gravity. Monthly global GPS data and an altimetry-assimilated relative ocean bottom pressure model are inverted for spherical harmonic surface mass variations. The concurrent low-degree spherical harmonic time series are compared with corresponding GRACE-derived series. Geographic comparison of the independent surface mass variation results is carried out after applying a Gaussian spatial filter. Good agreements are seen in both spherical harmonic and geographical domains. We also obtain a joint solution of surface mass harmonics using GPS and GRACE data combination. The two independent data sets are highly complementary to each other. Combining them can achieve a more complete picture of the surface mass variations by including robust degree-1 surface mass estimates, which reflect the longest-wavelength hemispherical mass exchange, but are not included in the gravity solution. The joint solution also improves long-wavelength estimates and serves to cross-validate the two techniques from their overlapping strengths.
DE: 1208 Crustal movements--intraplate (8110)
DE: 1214 Geopotential theory and determination
DE: 1243 Space geodetic surveys
DE: 1645 Solid Earth
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting