Tides and sea-level variability in the south-west Pacific from TOPEX/Poseidon

A harmonic-analysis technique is used to compute tidal amplitudes and phases over the south-west Pacific Ocean from the first 300 cycles (up to November 2000) of TOPEX/Poseidon satellite altimetry. The analysis is performed along groundtracks and at track crossover locations and the resultant harmonics are shown to compare favourably with those from open-coast sea-level gauges and from regional and global tidal models. Small-scale oscillations (<400 km) in along-track amplitudes and phases are used to identify likely regions of M-2 internal tide generation, or aliasing between K-1 and semi-annual signals. Tidal harmonics derived from satellite altimetry were used to improve the open-sea boundary forcing for a limited-area tidal model and produce a better validation with coastal sea-level gauges.