Abstract

Newly gathered hydrographic data from the Eastern South Pacific is combined with other high-quality data (mainly WOCE) to reassess the properties and boundaries of the Eastern South Pacific Intermediate Water (ESPIW); to date the ESPIW has been only poorly described. The ESPIW core is found off central and northern Chile, between the coast and 90°W and 20-38°S. Located at 50-400 m of depth, its temperature varies between 11-13°C, salinity ranges from 34.1-34.3, and its sigma-t lies between 25.75-26.25 kgm-3. ESPIW spreads with the subtropical gyre circulation and can be traced to at least 150°W. Formed through the process of subduction southeastward of the wind-driven gyre circulation, the ESPIW communicates surface properties of the waters off central Chile to tropical latitudes.