OCEANIC TIDES FROM GEOSAT ALTIMETRY

Direct tidal analysis of the altimetry from the Geosat Exact Repeat Mission's first year is used to derive estimates of the diurnal and semidiurnal oceanic tides. Global admittance maps for M2 and S2 within the latitudes 58°N and 59°S compare well with ground truth at 66 open-ocean sites. Maps of differences between Geosat and the Naval Surface Weapons Center model show important areas of the order of 10-15 cm. The integral for the global power input from the moon gives 2.51 TW(M2), 0.44 TW(S2), lower than many previous estimates, but in agreement with figures deduced from a recent analysis of satellite orbits. -from Authors