Finite volume ocean circulation model

A three dimensional finite volume ocean circulation model with a free surface is presented. The basic equations are transformed from differential into integral forms using the hydrostatic and anelastic approximations. The integral equations are solved for finite volumes (rather than grid points) with the flux conservation easily enforced even on arbitrarily meshes. Moreover, this model can easily incorporate the upwind scheme to increase the computational stability and the high-order combine compact schemes to enhance the accuracy. For abrupt topography, a crystal grid discretization is designed to reduce computational errors such that the four lateral boundaries of each finite volume are perpendicular to x and y axes, and the two vertical boundaries are not purely horizontal. This grid system reveals a superior feature than z- and sigma coordinate systems. The accuracy of this model was tested by the standard seamount test case.