The Agulhas Current in March 1969

Abstract

Quasi-synoptic data from a multiship cruise over virtually the whole length of the Agulhas Current from which dynamic, transport, and property analyses were made, provides for the first time a reasonably complete picture of the course of the current (down to intermediate depths), between Oro Point to its terminal region south of Cape Agulhas.

An important tributary joining the current just south of Durban and off-shore deflections just north of the confluence and near East London and Port Elizabeth, have been identified. The main retroflexion occurred at 20°E, after which the remarkably coherent Agulhas Current flowed back along a reciprocal path for 500 nautical miles^† (a unique western boundary current feature), and then executed a sharp planetary wave-like oscillation after rounding the Agulhas Plateau.

The probable importance of the Agulhas Plateau in directing the Agulhas Return Current along a course that offers opportunity for interaction with the closely adjacent parent current, is suggested.

Comparison of the deduced course of the current with the trajectories of satellite tracked drifters encourages confidence in the geostrophic method.