Ocean-to-shelf signal transmission: A parameter study

Oceanic signal transmission onto and across the continental shelf to the coast is investigated, focusing on pressure and surface elevation. The model used represents a uniform cross-slope section on an "f-plane'' with stratification, along-shelf wave number, and oscillatory frequency. (Inclusion of "beta'' and probably a fully three-dimensional numerical model would be necessary to treat all forms of oceanic signal.) At the model's oceanic boundary, care is needed for the prescription of the oceanic signal to be physically realistic. Then substantial transmission across the slope and shelf is limited to ( 1) large response near a dispersion relation for a coastal-trapped wave and ( 2) large along-shelf scale relative to a frictional-decay distance for coastal-trapped mode 1; that is, friction aids signal transmission. As a consequence, coastal gauges are likely to be effective monitors of only the largest-scale oceanic motion ( typically thousands of kilometers).