A Simple Model for Stratified Shelf Flow Fields with Bottom Friction

Abstract

Abstract The effect of bottom friction on the subinertial frequency motion of stratified shelf flow fields is studied in a two-layer f-plane model with idealized shelf and slope bottom topography. Coastal-trapped fire waves and motion forced by the alongshore component of the wind stress at the coast are considered. Vertical turbulent-diffusion effects are assumed to be present in thin surface and bottom-boundary layers, but not at the density interface. Simplifications are achieved by assuming that typical alongshore scales are larger than the offshore scales given by the internal Rossby radius of deformation δ–R and the shelf-slope width, that the upper-layer depth is small compared with the lower-layer depth, and that the topography of the continental margin may be represented by a linear bottom slope of small magnitude. Some results are not dependent on the presence of variable bottom topography; these are obtained first with a flat-bottom ocean adjacent to a vertical coast. A characteristic feature o...