On the variation of ocean circulation produced by bottom topography

The three dimensional circulation produced by a given wind stress in a homogeneous ocean with an arbitrary bottom topography is studied. The solution is illustrated by the use of various bottom shapes and a particular wind stress distribution. It is shown that in general a current deviates southwards in a region of decreasing depth and northwards in a region of increasing depth. However, if the wind stress has a perturbation out of phase with the bottom corrugations this result is considerably modified. Moreover, when there is a deepening of the ocean towards the north there may exist a “critical line” which δ/δy(f/H) is zero (f is the Coriolis parameter, H is the depth and y is the northward co-ordinate). The oceanic circulation is then divided into two parts: if the wind stress curl is positive, then for latitudes north of the “critical line” δ/δy(f/H) is positive the Sverdrup-topographic interior flow is basically northward and there is an eastern boundary current, while for latitudes south of the critical line, where δ/δy(f/H) is negative the interior flow is basically southward and there is a western boundary current.