3-D global overturning diagram, from Lumpkin and Speer (2006). The diagram illustrates some of the key roles the Southern Ocean plays in the climate system. The Southern Ocean buffers the rest of the world from the frigid conditions of the Antarctic continent, while meridional overturning across the Antarctic Circumpolar Current is the mechanism for the exchange of heat, Carbon Dioxide and other climate anomalies from the surface to the deep World Ocean

The icy Benguela current moves north from the Southern Ocean (around Antartica) and flows northwards along the West Coast of Africa. Along with the accompanying winds the Benguela current reaches as far as southern Angola, making it extremely difficult to travel southward along the Atlantic Coast. Where the icy Benguela meets the warm, south- and west-flowing Agulhas, there is a rich sea life beneath the surface, but tremendous turbulence above. South African folklore considers the meeting of the two currents--the cold Benguela and the warm Agulhas--(roughly off the Cape of Good Hope) as the place where the two oceans meet.

Agulhas Current and Agulhas Retroflection (south of Africa) and associated currents and eddies (from Peterson and Stramma, 1991; after Lutjeharms and van Ballegooyen, 1988).