Wind-driven cross-equatorial flow in the Indian ocean

Abstract

NCEP Wind-stress and temperature and salinity data from Argo have been used togetherwith a steady model to estimate the meridional velocity and volume and heat transport in theEquatorial Indian Ocean for a seven years period (2003-2009). Total volume transport of thewind stress curl shows a northward and southward flow for the Winter and Summer Monsoon,respectively. The velocity section shows a Somali Current flowing in opposite direction inthe Winter and Summer Monsoons. In the Winter Monsoon, the Somali Current is shallow(∼200 dbar) and flows to the south with and undercurrent below it. In the Summer Monsoonand Transitional Periods, the Somali Current flows to the north and to the south, respectivelyand extend to (∼650 dbar) depth. The heat transport across the Equator presents a seasonalreversing, being -0.8 PW to the south in the Winter monsoon and +1.2 PW in the SummerMonsoon. The annual heat transport is -1.4 PW that is mainly carried out by the SomaliCurrent.