The differences between two global satellite altimeter-derived gravity anomaly grids over the East China Sea and the Taiwan Strait are investigated and the causes of the differences are discussed. Difference of gravity anomaly is correlated with tide model error, standard deviation of sea surface heights (SSHs) and ocean depth. We present two new SSH-derived observations of altimetry (differenced height and height slope) for gravity derivation. An iterative method for removing altimeter data outliers is used, and differenced height is found to be most sensitive to this method. For altimeter-gravity conversion, we used three altimeter-derived observations, i.e., deflection of the vertical, differenced height and height slope, in two conversion methods, i.e., the least-squares collocation (LSC) and the inverse Vening Meinesz method. Use of differenced heights in LSC produces the best result when comparing altimeter-derived and shipborne gravity anomalies. Use of land gravity data in the vicinity of coasts enhances the accuracy of altimeter-derived gravity anomalies.
|Number of pages||11|
|Journal||Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an|
|State||Published - 1 Jan 2008|
- East China Sea
- Gravity anomaly
- Satellite altimetry
- Taiwan Strait