What is the only ocean surrounding Antarctica, according to the modern five-ocean model?

The Southern Ocean is the ocean surrounding Antarctica in the modern five-ocean model.

The Southern Ocean encircles Antarctica and connects the southern parts of the Atlantic, Pacific, and Indian oceans. Its northern boundary is commonly defined by the Antarctic Circumpolar Current, which flows eastward around the continent. This current links the major ocean basins and helps isolate Antarctica’s cold climate.

The International Hydrographic Organization proposed a Southern Ocean boundary in 2000, and the National Geographic Society began recognizing it as the world’s fifth ocean in 2021. Definitions have varied, so older maps and reference works may list only four oceans or use different northern limits.

The Antarctic Circumpolar Current is the only ocean current that circles the planet uninterrupted by a continent. It transports enormous volumes of water and influences global heat, carbon, and nutrient movement. The Southern Ocean also supports ecosystems built around krill, which feed whales, seals, penguins, and many seabirds. The ocean is not the same as the Antarctic coastal seas, although those seas are part of its broader region.