Modeling the East Australian Current in the Western Tasman Sea

Abstract

The East Australian Current (EAC) is a western boundary current flowing southward off the east coast of Australia. Its eddy variability has been shown to be vigorous, a typical feature being the formation of a large warm core eddy in the western Tasman Sea. The dynamics controlling the development of such an eddy are the subject of this paper. The Princeton Ocean Model was tuned for conditions that prevail in the western Tasman Sea, and initialized with features based on the Royal Australian Navy weekly temperature charts. A 70-day simulation initialized with summer conditions captures the formation of a large warm core eddy that matches fairly well the observations. Analyses of the results demonstrate that the formation of these eddies is associated with a wide range of dynamical aspects observed in the region, such as oscillation and propagation of the Tasman Front, EAC separation from the coast, formation of cold-core frontal eddies, and nutrient enrichment of coastal waters.