Subantarctic Surface Water

Subantarctic Surface Water is a water mass found in the Southern Ocean, formed by the mixing of warm subtropical surface currents and cold Antarctic Surface Water. This mixing occurs in a broad zone between the Subtropical Convergence (around 40° S) and the Antarctic Convergence (between 50° and 60° S).1

This water mass is characterized by temperatures between 37° and 45° F (3° to 7° C) and salinities of 33.8 to 34.5 parts per thousand. The Antarctic Convergence is a significant oceanic boundary where rapid changes in temperature and salinity occur, influencing climate and marine life.21

The Antarctic Circumpolar Current, a major eastward-flowing current, plays a crucial role in the Southern Ocean, transporting seawater and diminishing differences between the Atlantic, Pacific, and Indian Oceans. Antarctic waters are less saline than tropical waters due to lower temperatures and less evaporation.31