Band structure of tropical countercurrent in the Indian Ocean

Abstract

Presence of subtropical countercurrent or tropical countercurrent was confirmed in the Pacific and the Indian Oceans as a continuous stretch of easterly flow. But with the observational data of CSK (Cooperative Study of the Kuroshio) an unexpected feature of band structure with alternate easterly and westerly flows was identified in the North Pacific. In the Indian Ocean due to paucity of oceanographic data at a closer interval such a band structure could not be identified. With the availability of oceanographic data at a closer interval along 65ᵒ and 90ᵒ E the geostrophic flow was worked out. Alternate bands of easterly and westerly flows with a band width about 1ᵒ latitude was indicated on the vertical section of the current structure and this feature was closely associated with the wavy structure of the isanosters.