A SOLVER FOR THE BAROTROPIC MODE IN THE PRESENCE OF VARIABLE TOPOGRAPHY AND ISLANDS

A scheme is presented for solving the equation for barotropic ocean ci rculation, taking into account the special character of the problem: n early inviscid motion following f/H contours in the ocean interior, wi th viscous effects closing the flow near western boundaries. Using a s pecial compact finite-difference discretization, the scheme generates boundary layers without spurious oscillations and without demanding ve ry high resolution. Sharp changes in topography and closed f/H contour s (e.g., in the vicinity of high sea mounts) are also handled by the s cheme in a way that localizes errors due to underresolved topographic features. Strategies are formulated for simplifying the connectedness of the domain by ''sinking'' the islands.