Transport contribution of the Good Hope Jet to the South Atlantic MOC

Influx of water mass on the eastern side of the South Atlantic Ocean occurs via the South Atlantic gyre commonly referred to as the Benguela Current, warm core Agulhas Current Rings, the Good Hope Jet along the shelf edge and Antarctic Bottom Water (AABW near the basin floor. Outflow occurs at depth on the slope in the form of the North Atlantic Deep Water (NADW). Components of a trans-Atlantic mooring array have been deployed over the last 2 years by South Africa, France, Argentina, Brazil and the USA to form the South Atlantic Basin Mooring Array (SAMBA) to measure these fluxes at 34.5°S. This is the counterpart to RAPID in the North Atlantic at 26°N. This paper presents the first measurements of the Good Hope Jet using ship-borne ADCP and bottom-mounted ADCP moorings. The data show that the Jet is nearly always present on the offshore boundary of the upwelling area but that transport is highly variable. Velocities approach 60 cm s^-1 and a gridded analysis of data confirm a mean northward transport of some 6 Sv. Wind stress and the offshore mesoscale eddy field is shown to be a strong driver of this variability.