Geosat altimeter observations of the surface circulation of the Southern Ocean

Abstract

The variability of sea level and surface geostrophic currents in the Southern Ocean is investigated from the first 26 months of unclassified Geosat altimeter data (November 1986 to December 1988). Because of problems unique to Geosat, it has been necessary to develop new techniques for analyzing the height data. These techniques are presented here, and the processed Geosat data are used to examine the relation between mesoscale variability and the mean circulation (as determined from historical hydrographic data). The two are shown to be significantly correlated, implicating the importance of hydrodynamic instabilities in the Antarctic Circumpolar Current. The geographical patterns of both the mean flow and the mesoscale variability are shown to be controlled by the bathymetry. -from Authors