Modeling Pack Ice as a Cavitating Fluid

Abstract Polar ocean circulation is influenced by fluxes of salt and freshwater at the surface as ice freeze in one location, is transported by the winds and currents, and melts again elsewhere. The motion of sea ice, moreover, is strongly affected by internal stresses that arise from the mechanical strength of the ice cover. A simple sea-ice dynamics model, allowing these effects to be included in large-scale climate studies, is presented. In this model a cavitating fluid behaviour is assumed whereby the ice pack does not resist divergence or shear, but does resist convergence. While less realistic than other rheologies that include shear strength, this assumption has certain advantages for long-term climate studies. First, it allows a simple and efficient numerical scheme, in both rectangular and spherical coordinates, which as developed here along with a generation to include shear strength via the Mohr-Coulomb failure criteria. Second, realistic ice transport is maintained, even when the model is driv...