On the recovery of ocean dynamic information from satellite altimetry

The dense coverage of short pulse mode GEOS‐3 altimeter data in the western North Atlantic provides a basis for studying oceanographic parameters of interest. Time variations in the sea surface heights were investigated in regional monthly models of the Sargasso Sea produced for six months between July, 1975, and April, 1976. The orbits used in reducing the altimeter data were computed using the GEM10 gravity field model and laser tracking data. Shortwave maxima and minima in the regional sea surface models were examined for correlations with surface and remote sensed infrared temperature data. On allowing for differences in the quantities being compared, a 90% correlation was obtained between the location of cyclonic eddies obtained from infrared imagery and sea surface height minima in the altimeter models. Estimates of the dynamic sea surface topography using the regional models and the Marsh‐Chang 5 Minute Gravimetric geoid were used to calculate the geostrophic current, assuming a non‐accelerated system and the absence of frictional and atmospheric pressure gradients. Comparison with oceanographic determinations and a discussion of the results are given.