Antarktistrømmen

Antarktistrømmen, known in English as the Antarctic Circumpolar Current (ACC), is the world’s largest ocean current. It flows eastward around Antarctica through the Southern Ocean, encircling the continent and linking the Atlantic, Pacific and Indian Oceans. The flow constitutes a continuous, circumpolar belt that transports vast amounts of water from west to east and helps maintain the distinct water masses north and south of its path.

The current is primarily wind-driven, energized by the strong westerly winds that circle the Southern Ocean. Its transport is on the order of 100–150 Sverdrups (Sv), with typical estimates around 130–140 Sv, making it the dominant current system in global ocean circulation. The ACC exhibits a complex vertical structure and is organized into several fronts, such as the Subantarctic Front and Polar Front, which mark transitions in temperature and salinity and influence regional water masses and nutrient distribution.

Ecological and climatic roles are significant. The ACC acts as a barrier that limits heat exchange between the subtropics and the polar region, contributing to the maintenance of Antarctic climate and sea-ice conditions. It also upwells nutrient-rich deep waters along its margins, supporting primary production and the broader Southern Ocean ecosystem. Variability in the ACC is driven by wind patterns and climate modes such as the Southern Annular Mode; some climate projections suggest that intensifying westerly winds could alter the current’s strength and its implications for sea ice and carbon and nutrient cycles.