Recovery of Yangtze River Basin Water Storage Variations by GRACE Observations

Using 43 monthly gravity models observed by GRACE satellites from January 2003 to September 2006,we estimate Yangtze River basin water storage variations.We examine how treatment of C20 and one-degree harmonics affect GRACE based the estimation of basin-scale water storage changes,using independently derived C20 harmonic from satellite laser ranging(SLR) observations and one-degree harmonics from geocenter seasonal variations.GRACE based water storage changes are compared with estimation from CPC hydrological model.Results show remarkably good agreement with CPC in the Yangtze River basin.Combining GRACE observations with SLR degree-2 spherical harmonic and geocenter seasonal variations apparently improves the estimation inYangtze River basin.