Coastal trapped waves, with application to the northeast pacific ocean

Abstract

The dispersion relation is derived for long coastal trapped waves of sub-inertial frequency that propagate along a single-step continental shelf in a two-layer fluid. When the internal (Rossby) deformation radius is smaller than the shelf width, we show that the dispersion relation can be factored exactly, giving two possible modes:(i) an internal Kelvin wave modified by topography;(ii) a continental shelf wave modified by the stratification. A detailed discussion of the eigen-functions associated with each of these modes is presented. Then the shelf wave dispersion relation is plotted for parameters applicable to the Oregon-Washington coast. Theoretical values for the periods and wavelengths predicted from these plots are shown to agree favorably with observed values for this region © Taylor & Francis Group, LLC.