Improving the understanding and prediction of ocean currents and the links between large-scale offshore variability and the response of the Australian shelf/slope boundary current systems is a priority research area for the Bluewater and Climate Node.

The waters around Australia form a complex intersection of the Pacific and Indian Oceans.  There are two major 'gateways' between these ocean regions; the Indonesian Throughflow (ITF), and the Tasman Outflow (TO).  The main large-scale influences on this ocean region arise from the two major subtropical gyre systems - the South Pacific in the east and the Indian Ocean in the west.  These 'gyres' are the pathways followed by the flow in each ocean basin and they span the ocean basins and flow in an anticlockwise direction.  These gyres produce two distinct surface current systems that provide the main oceanic influence on the coastal boundaries off eastern Australia, the East Australian Current (EAC) and off western Australia, the Leeuwin Current (LC).  

Key Science Questions

• How are climate-change-related variations in the global circulation of momentum, heat, salt and nutrients modulated by the Australian gyre connection?
• How do the two Pacific-Indian throughflow components vary temporally?
• How does the time-varying flow of the ITF influence the Leeuwin Current and the southwestern Australian shelf?
• How does the mass and heat transport of each of the components of the Australian boundary system vary on timescales from interannnual, to multi-decadal?
• What are the dynamics associated with the temporal changes in the South Equatorial Current bifurcation location?What controls the EAC separation?
• How is the EAC partitioning between the Tasman Front and EAC Extension varying over time?
• What is the formation mechanism of EAC eddies, how are they related to the mean flow and how does eddy field vary temporally?
• What are the temporal changes in the advective and air-sea components of the EAC, and Leeuwin Current heat flux distributions?
• What forcing mechanisms drive the seasonal cycles of the EAC and Leeuwin Current?
• What are the underlying dynamics of the Holloway Current and how is it related to the Leeuwin Current?