Abstract
It is known from recent theoretical studies on coastal upwelling that in the linear model a finite depth of the upwelling regime can only be obtained when turbulent diffusion is included. In this note it is shown that, although a consistent solution is possible when only vertical diffusion is considered, the type of the solution depends strongly on the ratio c of the horizontal to the vertical Prandtl numbers associated with turbulent exchange of properties. For c=0 (i.e., no horizontal diffusion), the depth of upwelling depends on the Brunt-Väisälä frequency N (i.e., the stratification) as N−½ and the solution exhibits a weak under-current, while for c=1 the dependence is like N−1 and the undercurrent disappears.
