Elliptic Solvers for Mediterranean Sea Ocean Modeling,
JAYCOR ALEXANDRIA VA INFORMATION SYSTEMS DIV
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Versions of two beta-plane ocean models suitable for use in the Mediterranean have been prepared. One has two-layers and topography, and the other is a reduced gravity one active layer model. They use both the direct and the preconditioned capacitance matrix techniques DCMT and PCMT for solving the constituent non-rectangular two-dimensional finite difference Helmholtz equations with Heumann boundary conditions. Because the ocean models use the primitive equations there are no special problems associated with the modeling of regions with islands, as there would be, for example, in a model using the vorticity stream-function formlulation. DCMT is generally faster but requires more memory than the preconditioned method, but PCMT is particularly suited to problems with large Helmholtz coefficients. Therefore the ocean models have been set up to use DCMT only for the external gravity wave mode, all other modes being solved by the PCMT to save storage these modes have a very large Helmholtz coefficient. Appendix 1 contains listing of the subroutine that interfaces the ocean models and the Helmholtz solvers.
- Physical and Dynamic Oceanography