Topographic influence on the pattern of flow through Bass Strait

Abstract

A laboratory simulation of the flow through Bass Strait has been made with the aid of a physical model of the topography, situated in a tank on a rotating turntable. The throughflow was driven by a continuous supply of homogeneous water to the western end that was uniform with latitude. The effect of the depth variations within the strait were realistically represented and had a controlling influence on the flow pattern. In particular, the uniform inflow from the west was directed towards the south-eastern region, guided along contours of constant depth around the central depression by approximate conservation of potential vorticity. West of Flinders Island, the flow then splits into a northward branch that flows toward the Victorian coast and leaves the strait near Gabo Island and a southern branch that leaves through Banks Strait. This modelled flow pattern is generally consistent with the outflows inferred from observed temperature and salinity fields.