The primary purposes of this numerical experiment was to assess the reliability of the CANDIE model by applying these models to a problem used by Haidvogel and Beckmann  in a comparison of several different model formulations. The tests include the influence of a steep-sided coastal canyon which represents a significant challenge for the step topography of z-level coordinate models. Haidvogel and Beckmann's tests show general agreement between models based on topography-following coordinates, but significantly different results were obtained with z-level models such as MOM. The results of DieCAST for the homogeneous test case also differ substantially from those of the sigma-coordinate models, largely due to dissipation associated with low order interpolations used adjacent to solid boundaries in DieCAST. However, the results of CANDIE are in good agreement with those of the sigma-coordinate models for both homogeneous and stratified coastal canyon experiments. These results clearly demonstrate that the differences found for both MOM and DieCAST are not due to intrinsic limitations associated with the use of Cartesian coordinates.
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