surface oceanic current encircling Antarctica and flowing from west to east. Affected by adjacent landmasses, submarine topography, and prevailing winds, the Antarctic Circumpolar Current is irregular in width and course. Its motion is further complicated by continuous exchange with other water masses at all depths. The volume of transport south of latitude 40° S is thought to be at least 25,000,000 cubic m (880,000,000 cubic feet) per second.