Observations of an Agulhas Undercurrent

An Agulhas Undercurrent has been directly measured on two occasions using a new acoustic current profiling technique (Lowered Acoustic Doppler Current Profiler, LADCP). The core of the Undercurrent is centred around a depth of 1200 m, against the continental slope and directly below the surface core of the south-westward flowing Agulhas Current. Maximum velocities of 30 cm s−1 to the north-east are observed in the Undercurrent, and its volume transport is 6 Sv (1 Sv = 106 m3 s−1), approximately one-tenth that of the Agulhas Current.