On a front between two rotating flows with application to the Flores Sea

The horizontal shape of the front between two water masses, which subcritically approach each other from different sides of a wedge of land, is considered using a simple model. It is shown that the angle of the wedge of land is critical to the behaviour of the solution and that for a finite Bernoulli head difference between the flows, no solution exists if the angle is greater than or equal to π. As the relative energy content of the flows changes, the model predicts an interesting discontinuity in the behaviour of the angle at which the front leaves the wedge. This theory is used to illustrate the behaviour at the front between the water masses of the Flores Sea and the Makasar Strait. It is shown that the observed upwelling in the region (June to August) is the result of a subsurface high pressure system established by the front. The detailed structure of the upwelling region is dependent on the Bernoulli head difference across the front in both the surface and subsurface water.