HR: 1340h
AN: G33A-0896    [Abstracts]
TI: GRACE: a Couple of Geodetic Satellites for Ocean Tide Determination ?
AU: * Biancale, R
EM: richard.biancale@cnes.fr
AF: CNES / GRGS, 18 avenue Edouard Belin Cedex 9, Toulouse, 31401, France
AU: Lemoine, J
EM: jean-michel.lemoine@cnes.fr
AF: CNES / GRGS, 18 avenue Edouard Belin Cedex 9, Toulouse, 31401, France
AU: Bruinsma, S
EM: sean.bruinsma@cnes.fr
AF: CNES / GRGS, 18 avenue Edouard Belin Cedex 9, Toulouse, 31401, France
AU: Bourgogne, S
EM: stephane.bourgogne@noveltis.fr
AF: Noveltis, avenue de l'Europe, Ramonville-St-Agne, FRA 31520,
AB: The GRACE mission has proved its pertinence for monitoring time variations of surface masses. Five years of geoid models from CNES/GRGS are now available at 10-day intervals on the BGI web site. They are delivered in terms of geoid and of equivalent water mass variation as well at a realistic spatial scale of 500 km and are used in the new global gravity models named EIGEN-5S and -5C produced in cooperation with GFZ. But if gravitational variations over 10 to 30 days can be relatively well modelled from GRACE GPS and K-band range-rate (inter-satellite) data, a new question is raised: can GRACE help improving long wavelength ocean tides models ? A positive answer would also help reducing aliasing effects already detected in geoid models. We have performed new computation of GRACE data over the year 2006, using a time variable a priori gravity model and adjusting along orbit and instrumental parameters some ocean tide spherical harmonic coefficients of main semi-diurnal and diurnal waves from the a priori FES2004 model. This GRACE ocean tide solution has been evaluated particularly in conjunction with altimeter crossover data from Jason1 and ENVISAT missions. Context, method and results are presented on poster.
DE: 1214 Geopotential theory and determination (0903)
DE: 1217 Time variable gravity (7223, 7230)
DE: 1222 Ocean monitoring with geodetic techniques (1225, 1641, 3010, 4532, 4556, 4560, 6959)
SC: Geodesy [G]
MN: 2007 Fall Meeting