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A continental shelf scale examination of the Leeuwin Current off Western Australia during the austral autumn-winter

Citation

Weller, E and Holliday, D and Feng, M and Beckley, L and Thompson, P, A continental shelf scale examination of the Leeuwin Current off Western Australia during the austral autumn-winter, Continental Shelf Research, 31, (17) pp. 1858-1868. ISSN 0278-4343 (2011) [Refereed Article]

Copyright Statement

Copyright 2011 Elsevier Ltd.

DOI: doi:10.1016/j.csr.2011.08.008

Abstract

A continental shelf scale survey from 22S to 34S along the Western Australia coast provides the first detailed synoptic examination of the structure, circulation and modification of the southward flowing Leeuwin Current (LC) during the late austral autumn-early winter (May-June 2007). At lower latitudes (22S-25S), the LC was masked within a broad expanse of warm ambient surface water, which extended across the shelf and offshore before becoming constrained at the shelf break and attaining its maximum velocity of ~1.0ms-1 at 28S. The temperature and salinity signature of the LC experienced substantial modification as it flowed poleward; surface temperature of the LC decreased by ~5.25C while surface salinity increased by ~0.72, consistent with climatology estimates and smaller (larger) for temperature (salinity) than those found during summer. Subsequently, LC water was denser by ~2σT in the south compared to the north, and the surface mixed layer of the LC revealed only a small deepening trend along its poleward trajectory. Modification of the LC resulted from a combination of mixing due to geostrophic inflow and entrainment of cooler, more saline surrounding subtropical waters, and convective mixing driven by large heat loss to the atmosphere. Air-sea heat fluxes accounted for 50% of the heat lost from the LC in the south, whilst only accounting for 25% in the north, where large geostrophic inflow occurred and the LC displayed its maximum flow. The onshore transport was characterised by distinct jet-like structures, enhanced in the upper 200m of the water column, and the presence of eddies in the vicinity of the shelf break generated offshore transport.

Item Details

Item Type:Refereed Article
Keywords:hydrodynamic model, Indian Ocean, Leeuwin current, ocean circulation
Research Division:Environmental Sciences
Research Group:Other Environmental Sciences
Research Field:Environmental Sciences not elsewhere classified
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Environment not elsewhere classified
Author:Feng, M (Dr Ming Feng)
Author:Thompson, P (Dr Peter Thompson)
ID Code:119697
Year Published:2011
Web of Science® Times Cited:16
Deposited By:Centre for Oceans and Cryosphere
Deposited On:2017-08-03
Last Modified:2017-09-25
Downloads:0

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