Decadal variability of the Indian Ocean cross‐equatorial exchange in SODA

Abstract

The mean meridional circulation across the equator in the Indian Ocean is characterized by the shallow Cross‐Equatorial Cell (CEC). At the western boundary, the Somali Current transports thermocline waters northward which then upwell, mostly off Northeast Africa. The upwelled waters are taking up heat and then exported back southward by southward near‐surface Ekman and Sverdrup transports. The CEC is closed by subduction in the southeastern subtropics and includes contributions from the Indonesian Throughflow. In an analysis of output from the SODA assimilation, a decadal slowdown of the different branches of the CEC is demonstrated here.