Exchange Processes in Cockburn Sound - a Seasonally Stratified Embayment Off Southwest Australia

Basin-wide oceanographic measurements in Cockburn Sound, a micro-tidal semi-enclosed seasonally stratified coastal basin adjacent to Perth, Western Australia, are used to highlight the importance of the seasonal evolution of vertical and horizontal density gradients in the hydrodynamics of this type of embayment, with particular reference to the strongly stratified winter regime. Although the wind-stress is a primary forcing factor, density gradients were found to influence the overall circulation and mixing throughout most of the year. The environmental management of Perth's coastal waters utilises numerical modelling as a key tool and the results of the physical characterisation described in this paper were important in the choice, validation and calibration of hydrodynamic models.