Interaction Between Estuarine Plumes and Continental Shelf Waters

摘要

A simple analytical model is developed to describe the steady flow in an estuary-shelf interaction region where the water is treated as a two-layer density stratified flow. The motion is expanded in terms of the relative thickness of the Ekman layer, E/sub v//sup 1/2/. The order-zero flow is geostrophic in each layer. Balancing of order-one quantities reduces the system to two vorticity equations relating the pressure field with the displacement of the interface and the bottom topography. An explicit solution is obtained for the case of linear offshore sloping bottom. The flow behaviour of the river water plume depends on the vertical structure of the flow at the river mouth, the bottom topography and the ambient coastal flow. Under certain conditions, a salinity front exists as an offshore boundary of the river plume. These results are compared with observations for the Changjiang River (in China), and the Chesapeake Bay and Savannah River (in US) estuaries. (ERA citation 11:057305)