William James Pringle , Damrongsak Wirasaet, Joannes J. Westerink

Parameterization of the tidal energy conversion from barotropic to baroclinic modes through internal tide generation over rough and steep submarine topography is a necessary dissipative force for barotropic ocean models. We present and unify two forms of parameterizations that differ by assuming that wave generation is either only due to the local topographic features, or that it includes the effects of nonlocal topographic features. Previously reported implementation schemes on structured grids are extended to unstructured grids. A positive definite modification to the nonlocal generation formulation is recommended to ensure dissipation everywhere. Modifying the buoyancy frequency variable used in the formulations, in order to redistribute some of the dissipation from shallow water into deeper waters, is also proposed. MATLAB functions to compute the necessary parameters on both structured and unstructured grids are highlighted and made available.