Tracking eddies in the southeast Atlantic and southwest Indian oceans with TOPEX/POSEIDON

Altimetric data from the first year of the TOPEX/POSEIDON mission and National Oceanic and Atmospheric Administration infrared imagery are used to investigate characteristics of eddies and rings in the oceans around southern Africa. Altogether, 57 eddies were identified. The Agulhas rings in the southeast Atlantic were mostly anticyclonic, drifted at 3-7 cm s(-1) in a westerly to northwesterly direction, and it was estimated that five rings are generated annually. Even in close proximity to the Agulhas retroflection, the altimetry provided insight into rings not visible on infrared imagery. The annual heat flux of five rings into the South Atlantic is estimated at 3-8 x 10(13) Watt. Eddy motion in the southwest Indian Ocean seemed more confused where a comparable number of cyclonic and anticyclonic eddies advected mostly in a westerly or northwesterly direction. Eddies were observed to adhere to and entrain water from the offshore edge of the Agulhas Current.