Empirical ocean tide models estimated from TOPEX/POSEIDON altimetry

摘要: Three empirical ocean tide models are determined from repeat cycles 10 to 78 of the TOPEX/POSEIDON (T/P) altimeter mission. The three investigate effects satellite orbit ephemeris on tides T/P altimetry and effect extracting free core nutation resonance in definition diurnal admittance. altimetric data series use Joint Gravity Model JGM-2 geopotential preliminary JGM-3 computed at University Texas, Center for Space Research. mission shown have precision necessary estimate monthly fortnightly each bin. Inclusion existing polar latitudes not sampled by demonstrates importance these spherical harmonic representations tides. first estimated bins size 2.834° longitude 1° latitude then smoothed grids within ±66° latitude. orthotide response formalism Groves Reynolds (1975) is used represent semidiurnal tides, while a constant admittance assumed across narrow bandwidths around (Mm), (Mf), termensual (Mt) tidal components. Comparisons gauge observations indicate their accuracies be order 2–3 cm. T/P-derived remove approximately 20 cm2 more measured sea surface variance than Cartwright Ray (1991) model show 19 15 improvement over Schwiderski (1980a, b) models, respectively, when compared estimates