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Convergence of Laplacian diffusion versus resolution of an ocean model
Author(s) -
Wallcraft Alan J.,
Kara A. Birol,
Hurlburt Harley E.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl022514
Subject(s) - ocean gyre , convergence (economics) , geology , diffusion , range (aeronautics) , turbulence modeling , convergence zone , grid , climatology , meteorology , subtropics , physics , geodesy , thermodynamics , turbulence , materials science , economics , economic growth , fishery , composite material , biology
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 1/2° and 1/32° and with horizontal eddy viscosity coefficient ( A H ) ranging from 8000 to 30 m 2 s −1 . A range of A 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 A H .