Search

The results of an intercomparison experiment performed with five numerical ocean models of different architecture are presented. While all models are able to simulate the large-scale characteristics of the North Atlantic circulation with a fair degree of realism, they also exhibit differences that can be attributed to the choices made in vertical coordinates, domain size, and boundary conditions.

We describe a simple, flux conserving robust advection scheme that reduces numerical dispersion in application to passive scalar advection. Our hydrostatic semi-collocated (modified Arakawa ‘a’ grid) ocean model performance is enhanced by this modification in combination with a modified strategy for incompressibility. The modified advection scheme also reduces overshooting errors resulting from numerical dispersion in the evolution of a sloshing front using a non-hydrostatic model. In Gulf of Mexico simulations, many of the realistic detailed features from our original model using 1/12° (about 9 km) resolution occur using the modified numerics with 20-km resolution. These are not seen with the original numerics and 20-km resolution. These detailed features include: strong fronts and frontal eddies; many cyclonic eddies, which spin off major warm core Loop Current eddies; and sharp eastward deflection of the Loop Current directly into the Florida Strait after major warm core eddy shedding.