Antarctic convergence

Diagram detailing Antarctic convergence, where the cold waters of the Antarctic circumpolar current meet and mingle with warmer waters to the north.
The major ocean currents south of 20S are shown by the arrows. The largest current in the world, the Antarctic circumpolar current, circles from west to east around Antarctica. (Diagram courtesy of Academic Press / de Vos Design) (Photo: Academic Press / de Vos Design)

This is the region of the Southern Ocean encircling Antarctica, roughly around latitude 55 degrees South (but deviating from this in places) where the cold waters of the Antarctic circumpolar current meet and mingle with warmer waters to the north. This intermixing creates local variations in weather (such as fogs) and also results in a concentration of marine plant life because of its higher than average nutrient concentrations. Increased plantlife leads in turn to a greater abundance of animal life.

For more information about ocean currents and the Southern Ocean see the magazine article The Southern Ocean's Global Reach