Ocean current detection by satellite altimetry

Seasat provided 3 months of satellite altimeter data in 1978 with a precision of approximately 5 cm. In the western North Atlantic where a detailed gravimetric geoid model is available, these data yield realistic profiles of Gulf Stream dynamic heights. A Seasat-type mission could thus produce near-synoptic maps of the Gulf Stream path with surface current measurements accurate to perhaps 50 cm/s. Because of a lack of detailed geoid models for most ocean regions, however, solutions of sea height variability represent the most significant contribution of altimetry. The 25-day set of Seasat repeat-track altimeter data permits determination of global mesoscale variability with an accuracy of a few cm. The map generated from these data displays patterns which clearly define the mean paths of most major surface current systems.