Modeling studies of the effects of seasonal wind forcing and thermohaline gradients on the Leeuwin Current System

Abstract

A high resolution, multi-level, primitive equation ocean model is used to investigate the effects of seasonal thermohaline gradients and wind forcing in the generation of currents and eddies off the western and southwestern coasts of Australia. Additionally, an investigation of the generation mechanisms for undercurrents in the region is conducted. Model results demonstrate the roles of seasonal thermohaline gradients, wind forcing, and North West Shelf waters in the Leeuwin Current System. While the basic flow is poleward and eastward off the western and southern coasts, due to strong thermohaline gradients, there is significant variability in the flow from the seasonal nature of the wind forcing and the onset of the North West Shelf waters. Model results also indicate that an equatorward (westward) undercurrent off the western (southwestern) coast of Australia is generated and maintained due to the conservation of mass continuity in response to an alongshore thermohaline gradient at deeper levels.