Convergence of Laplacian Diffusion Versus Resolution of an Ocean Model
NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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This paper presents a convergence study for second order finite difference Laplacian diffusion used in ocean models. For demonstration, ocean model simulations are performed over a rectangular domain, based on the North Pacific subtropical gyre region with grid resolution between 12 deg. and 132 deg. and with horizontal eddy viscosity coefficient Asub H ranging from 8000 to 30 m2s-1. A range of Asub H which is appropriate for useful model simulations of an oceanic domain is found to exist. This range is determined by examining the spatial patterns of Eddy kinetic energy and mean sea surface height. The results fall into three broad categories a converged, b converging, and c numerical problems. Solutions in the converged category do not change with increased grid resolution, and solutions in the numerical problems category exhibit distinct differences to the converged result at the same Asub H.
- Physical and Dynamic Oceanography
- Numerical Mathematics