HR: 10:50h
AN: G51C-03 INVITED     [PDF]
TI: Seasonal Geodetic Signatures and Global Surface Mass Variations
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@mailhost4.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: The hydrosphere, cryosphere and atmosphere are volatile layers of the Earth. Their dynamic motions involve significant horizontal surface mass transport at the seasonal time scale. The changing mass loads and deforms the solid Earth surface, perturbs the external gravity field, and excites Earth orientation variations. Recent advancement and proliferation of space geodetic techniques allow all these different signatures to be accurately measured. More importantly, we can use the geodetic information to infer the mass variations and learn about the associated global change processes. Using continuous GPS data from a globally distributed tracking network, we have conducted monthly inversions for global surface mass variations in terms of truncated spherical harmonic series. A combined hydrological, atmospheric and oceanic mass distribution model is also used to assist the truncations and error evaluation. The seasonal amplitudes and phases of the mass coefficients are converted to those of geocenter and zonal gravity coefficients, and compared with corresponding SLR results from previous authors. Good agreements are found at the lowest degrees where results appear to be reliable for both techniques. Satisfactory comparison not only validates both measurement techniques but also reinforces the overarching theory of surface mass variations. New inversion results using more data and a combination of least squares and best linear estimator techniques under the platform of singular value decomposition will also be reported.
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1243 Space geodetic surveys
DE: 1645 Solid Earth
DE: 3260 Inverse theory
SC: Geodesy [G]
MN: 2003 Fall Meeting