The Agulhas Current is the major western boundary current of the Southern Hemisphere. It completes the anti-cyclonic gyre of the South Indian Ocean, and because the African continent terminates at a relatively modest latitude, it becomes a mechanism for the climatologically important inter-ocean exchange between the Indian and Atlantic oceans. The southwestward flowing Agulhas Current only becomes fully constituted along the east coast of southern Africa at a latitude somewhere between Durban (South Africa) and Maputo (Mozambique). It increases in speed and volume flux downstream. On average, its volume flux is 70 × 106 m3/s, with only small temporal changes. Its depth, by contrast, can vary from 6561 ft. (2,000 m) to the sea floor at 9,842 ft. (3,000 m) over a period of months. It is underlain by an opposing undercurrent at a depth of 3,937 ft. (1,200 m), with a maximum velocity of about 0.2 m/s and carrying about 4 × 106 m3/s equatorward.
An offshore profile of the surface speed of the current shows a peak of about 1.5 m/s close inshore, slowly tapering off to about 0.2 m/s at a distance of roughly 62 mi. (100 km) offshore. The temperature of its surface waters is about 11 degrees F (6 degrees C) higher than ambient waters and decreases from 80 to 71 degrees F (27 to 22 degrees C) from summer to winter.
