Poleward boundary current off Western Australia

Abstract

The southern Indian Ocean is modelled here as a body of homogeneous water with a shelf and slope region on the eastern side. A 'Leeuwin Current' is found to be the poleward extension of a boundary current generated on the north-west slope of Australia by winter winds. Simple, approximate balances demonstrate that a current forced in one region can propagate in the direction that a Kelvin wave travels but not in the reverse direction. Thus, the Leeuwin Current can be induced by winds acting north of Cape Leeuwin but not by winds in the Great Australian Bight. This study also predicts the existence of a southward current off the western coast of Tasmania.