HR: 1330h
AN: G32A-0729    [PDF]
TI: Independent Determination of Low Degree Gravitational Changes From Earth Rotation and Geophysical Models
AU: * Chen, J
EM: chen@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin, 3925 W. Braker Lane, #200, Austin, TX 78759 United States
AU: Wilson, C
EM: clarkw@maestro.geo.utexas.edu
AF: Center for Space Research, University of Texas at Austin, 3925 W. Braker Lane, #200, Austin, TX 78759 United States
AU: Wilson, C
EM: clarkw@maestro.geo.utexas.edu
AF: Department of Geological Sciences, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712 United States
AB: Changes in the Earth's rotation are caused by mass redistribution and movement within the Earth system (i.e. mass and motion effects). The successful separation of mass and motion excitations of the Earth's rotation provide people a unique opportunity to independently determine the degree 2 gravitational changes. These results can serve as observational constraints to the GRACE observation. In this study, we estimate atmospheric wind and oceanic current effects on the Earth's rotation using NCEP reanalysis atmospheric model and the ECCO data assimilating ocean general circulation model developed at NASA JPL. After these two kinds of effects are removed from the Earth's rotational observation, the remaining excitations are used to infer the degree 2 spherical harmonic change. We will compare these preliminary solutions with geophysical model predictions and satellite laser ranging observations, and estimate uncertainties of these solutions.
DE: 1200 GEODESY AND GRAVITY
DE: 1214 Geopotential theory and determination
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1239 Rotational variations
DE: 4532 General circulation
SC: Geodesy [G]
MN: 2003 Fall Meeting