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The vertical structures of three warm-core Leeuwin Current eddies are described, as well as their temporal evolution determined from altimetric data. These warm-core eddies have large positive sea-level anomalies, although their surface temperature fields are not necessarily warmer than the ambient waters. These eddies were observed some 350 km offshore from the Leeuwin Current in September 2000, around 25–30°S, and their vertical structure and temporal evolution show they were formed at the coast in May, when the Leeuwin Current is strongest. After separation from the current, the warm-core eddies drifted WNW following isopycnal contours, and were strongly steered by bathymetry. These eddies penetrated to at least 1500 m depth; the strongest eddy, Eddy B, influenced isopycnals to 2500 m. Eddy B appeared to be trapped and intensified by a Leeuwin Current squirt that directed warm, low-salinity water offshore from August to October. The average annual eddy heat and salt fluxes for waters warmer than 8°C are estimated at 0.004 PW and 3×105 kg s−1, respectively. The magnitude of these eddy fluxes is 20–30% of the annual mean poleward heat and salt flux in the eastern Indian Ocean, and is within the range of values observed for Agulhas eddies entering the South Atlantic. [Copyright &y& Elsevier]

Characteristics of eddies originating in the Leeuwin Current (LC) have been investigated using 10-day sea-level anomaly maps of combined TOPEX/POSEIDON and ERS altimeter data for the period 1995–2000. During these 6 years, 37 long-lived anticyclonic eddies were tracked from the west coast of Australian to 90°E. Between three and nine eddies were spawned each year, and their trajectories are described in detail. Most long-lived eddies are generated in May–June, when the LC is most intense, and at three preferred locations: 20–21.5°S, 24–25°S and 28°–31°S. The temporal evolution and latitudinal variations of the sea-level anomalies and their radius and drift speed are discussed. Topography plays an important role in the evolution and structure of the eddies. Interactions with topography can induce splitting or merging of eddies which further affects the eddy decay. [Copyright &y& Elsevier]