Deep, Zonal Subequatorial Currents

Abstract
Large-scale, westward-extending tongues of warm (Pacific) and cold (Atlantic) water are found between 2000 and 3000 meters both north and south of the equator in the Pacific and Atlantic oceans. They are centered at 5° to 8° north and 10° to 15° south (Pacific) and 5° to 8° north and 15° to 20° south (Atlantic). They are separated in both oceans by a contrasting eastward-extending tongue, centered at about 1° to 2° south, in agreement with previous helium isotope observations (Pacific). Thus, the indicated deep tropical westward flows north and south of the equator and eastward flow near the equator may result from more general forcing than the hydrothermal forcing previously hypothesized.