Leeuwin current

The Leeuwin Current (LC) flows over 5500 km from northwestern Australia to Tasmania, with progressive changes in its water properties. Initially it flows poleward as a near-surface, warm, low-salinity stream of tropical water to Cape Leeuwin (∼35 ° S, 115 ° E). En route, it is augmented by cooler subtropical water from the west that progressively lowers its temperature and increases its salinity. Turning eastward at Cape Leeuwin, and frequently accelerating, it enters a cooler, less-saline regime, with which it exchanges water through entrainment and eddy formation. The LC can reach speeds over 1.5 m s−1. It is strongest during La Niña years and in austral winter, when it spreads onto the continental shelf. Southerly wind forcing in austral summer drives a northward current on the western shelf, the Capes Current, displacing the LC further offshore. Eddies forming from unstable meanders of the LC drift west into the Indian Ocean, with a tendency to deflect (equatorward) poleward in the case of (anti-)cyclonic motion. Anticyclonic eddies that form north of Cape Leeuwin often entrain waters from the continental shelf. Beneath the LC is the cooler and saltier Leeuwin Undercurrent that extends from c. 300 to 700 m and has speeds around 0.3 m s−1.