The relationship between the grid size and the coefficient of nonlinear lateral eddy viscosity in numerical ocean circulation models

Abstract

When a constant coefficient of lateral eddy viscosity v 0 is used in ocean circulation models, a false computational space oscillation is generated in the western boundary region if v 0 is smaller than a critical value. The use of a nonlinear eddy viscosity coefficient based upon two-dimensional turbulence theory is shown to permit the use of an eddy viscosity which, away from the western boundary region, is at least an order of magnitude smaller than the above critical value.