This offshoot of the Circumpolar Current carries cool water north along the coast of South America until it encounters water pouring out of the Rio de la Plata.
The convergence of warm and cold currents off the coast of Patagonia helps fuel large blooms of phytoplankton. This pair of images shows temperature and chlorophyll in November 2009.
The waters off of southwestern Africa are some of the most biologically productive in the world. They also provide a compelling backdrop for exploring how satellite sensors can reveal important details of the ocean.