The ocean tide gravimetric loading reconsidered

Abstract

In 1994–95, a set of new global ocean tide models computed by different teams was made available to the scientific community. These models were derived from the analysis of satellite altimetric data, numerical hydrodynamics or a combination of both. The task is now to evaluate their relative accuracy, in particular with independent data. The data bank prepared by the International Center for Earth Tides (ICET, Melchior 1994) gives us a unique opportunity to compare the tidal models by testing their capability to predict the induced gravimetric loading effects. The more recent versions (released in 1995) of the models by Ma et al. (1994) and by Schrama and Ray (1994) both completed at high latitudes by the Le Provost et al. (1994) FES94.1 model have the best scores for the semidiurnal M2 wave, with a standard deviation (SD) of the gravimetric data residues less than 0.540 µgal. Schwiderski (1980) and Egbert et al. (1994) models give the smallest residual SD, about 0.370 µgal, for the diurnal O1 component. However, the ordering of the models may change when we focus on some particular regions of the globe.