The South Indian Ocean Shallow Overturning

The circulation of the South Indian Ocean has several characterisic features: the Indian - Pacific throughflow via the Indonesian Passages, the Leeuwin Current that is an exceptional eastern boundary current and east of Madagascar the 'South Indian Counter Current' that flows eastward against the direction imposed by the wind field.

The SICC connects to the subduction region west of Australia and may be one of the sources of the Leeuwin Current. Subducted waters return westward as sub surface meso scale eddies. The result is a shallow overturning circulation system that may play a role in the vast plankton blooms that 'light up' intermittently East of Madagascar.

It is timely to draw a coherent picture of this shallow south Indo-Pacific circulation, including its dynamics and its connections with the Atlantic and Pacific Oceans.