Ocean tide model obtained from TOPEX/POSEIDON altimetry data

Tidal corrections are very important for oceanographic study of altimetry because tidal signals contaminate the low-frequency part of raw altimetric signals. Accurate tidal predictions are also necessary for geophysical research, such as with the superconducting gravimeter (SCG), which needs to distinguish very weak signals from the overwhelming tidal signals. The aim of this paper is to derive accurate global ocean tide models from the TOPEX/POSEIDON sea surface height data of 5 cm accuracy, more accurate than any other previous altimeter data. TOPEX geophysical data records of cycles 9-94 were processed and analyzed. We describe response analysis of tidal waves at crossover points and application of hydrodynamical interpolation. The tidal solutions with 0.5 degrees grid system are obtained for eight major constituents (i.e., M(2), S-2, N-2, K-2, K-1, O-1, P-1, and Q(1)) and compared with the Schwiderski (1980a, b, c) model, the Cartwright and Ray (1991) model, and the eight-constituent version of the Egbert et al. (1993) model or TPXO.2. The accuracy of the models is checked using island and bottom tide gauge data in open ocean and using SCG data in Antarctica and Japan.