Leeuwin Current

Overview

The Leeuwin Current is a warm ocean current that originates in the tropical Indian Ocean and flows southwards along the western coast of Australia. As one of the few eastern boundary currents that transport warmer, lower salinity water polewards, it has a significant influence on the climate and marine life of Western Australia.

Physical Characteristics

The Leeuwin Current is characterized by its warm, low-salinity water, which contrasts with the cooler, higher salinity waters of the surrounding Indian Ocean. It is driven by a pressure gradient set up by a pile-up of warm water in the Indonesian region, rather than wind stress, which is the driving force for most other ocean currents. The current flows southwards along the Western Australian coast, with a width of approximately 50 km and a speed of 1-2 knots.

Climate Influence

The Leeuwin Current has a significant impact on the climate of Western Australia. It transports warm tropical water southwards, resulting in a warmer and wetter climate along the western coast of Australia than would otherwise be expected at such latitudes. This has important implications for regional weather patterns, rainfall, and the occurrence of extreme weather events.

Biological Significance

The Leeuwin Current plays a crucial role in the distribution and abundance of marine life in the region. It provides a pathway for the southward transport of tropical marine species, contributing to the high biodiversity of Western Australia's marine environment. The current also influences the distribution of commercially important fish species, and is critical for the survival of some endangered species.

Impact on Human Activities

The Leeuwin Current affects a range of human activities, including fishing, shipping, and offshore oil and gas operations. Its warm waters and associated weather patterns can influence fish populations and their distribution, affecting commercial and recreational fishing. The current can also create hazardous conditions for shipping and offshore operations.

Research and Monitoring

Research into the Leeuwin Current has increased our understanding of its physical characteristics, its influence on climate and marine life, and its potential responses to climate change. Monitoring of the current is conducted through a combination of satellite observations, in-situ measurements, and numerical modelling.