Circulation induced by river inflow in well mixed water over a sloping continental shelf.

Abstract

The pressure field over a sloping continental shelf subject to freshwater runoff at the coast can be resolved into a nearly two dimensional dynamic height field and a residual field, the latter arising from the interaction of baroclinity and topography. The residual field is essentially three dimensional and so constituted as to supply the fluid for the baroclinic alongshore flow off a coastal source of buoyancy associated with the cross isobath density gradients. The intensity of the induced residual circulation (its total transport in m SUP 3s SUP - SUP 1) varies directly with the buoyancy input and bottom slope, and inversely with the zero order alongshore flow velocity and Coriolis parameter. Over the Mid Atlantic Bight continental shelf the runoff induced residual circulation make a generally weak contribution to the observed mean flow field. It could, however, be more important over a low latitude shelf subject to high runoff. (A)