The ocean current that carries warm water south along Africa and leaks into the Atlantic is the Agulhas Current. It is a powerful western boundary current of the southwest Indian Ocean, flowing along Africa’s southeastern coast.
Near the southern tip of Africa, the current turns back toward the Indian Ocean in a process called retroflection. It does not pour entirely into the Atlantic. Instead, rings, eddies and filaments periodically break away, carrying warm, salty Indian Ocean water into the South Atlantic; this transfer is known as Agulhas leakage.
That leakage matters far beyond southern Africa. It adds heat and salt to the Atlantic and can influence the Atlantic’s large-scale overturning circulation and climate. Agulhas Rings may reach hundreds of kilometres across and transport substantial volumes of water.
The current is named after Cape Agulhas, the geographic southern tip of Africa. The cooler Benguela Current, by contrast, flows northward along southwestern Africa in the Atlantic, so it is not the warm Indian-to-Atlantic current described here.