HR: 1340h
AN: G33B-0039    [Abstracts]
TI: Validation of the temporal ocean mass variations from GRACE with in-situ observation
AU: * Munekane, H
EM: munekane@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin, 3925 West Braker Lane, Suite 200, Austin, TX 78759-5321 United States
AB: We validated the GRACE-derived temporal ocean mass variations from the period 2002.8-2004.8 with the two independent sets of in-situ observations. One set is the ocean mass variations at the TAO-TRITON moored-buoys. In this case, the ocean mass variations are obtained by subtracting the steric sea level changes estimated from the temperature profile measurements from the altimetric sea level changes. The other set is the ocean mass variations measured by the Bottom Pressure Recorders (BPRs) in the Deep-ocean Assessment and Reporting of Tsunamis (DART) array. Prior to the comparison, the degree-one Stokes_f coefficients are estimated to minimize the GRACE-derived and in-situ variations in the least-square sense. After adjusting for the degree-one Stokes_f component, we find that the ocean mass variations from GRACE correlate significantly with the in-situ variations. At the TAO-TRITON buoys, the GRACE-derived variations and in-situ variations have the correlation coefficient of 0.61 and the admittance 0.95+-0.04. At the DART BPRs, they have the correlation coefficient of 0.65 and the admittance 0.83+-0.14. The obtained degree-one Stokes_f coefficients in terms of the geocenter motions generally agree with those derived from the SLR observations. However, adopting the SLR-derived values for degree-one Stokes_f coefficients results in the degradation of the correlations, namely, to 0.23 at the TAO-TRITON buoys and to 0.08 at the DART BPRs. These results confirm the validity of the GRACE-derived ocean mass variations, and also show the possibility of using the comparison as a mean to estimate precise geocenter motions comparable to those derived from other space techniques.
DE: 1214 Geopotential theory and determination (0903)
DE: 1243 Space geodetic surveys
DE: 1640 Remote sensing (1855)
SC: Geodesy [G]
MN: Fall Meeting 2005