The Generation of Continental Shelf Waves by Alongshore Variations in Bottom Topography

Abstract

Abstract The effects of alongshore variations in bottom topography on wind-stress-forced barotropic motion over a continental shelf and slope are studied. An idealized channel model with a weakly sloping bottom and with small-amplitude alongshore variations in topography is utilized. Perturbation methods and numerical inversion of Fourier transforms are employed. The effect of a localized alongshore topographic disturbance is examined in the context of an initial-value problem, where a spatially uniform wind stress is applied at t = 0. The wind stress forces a basic unperturbed alongshore velocity V which is constant in space. Shelf waves are forced by the interaction of V with the topographic disturbance. Two types of time variation of the wind stress are considered, a Dirac delta function and a Heaviside unit function. These force, respectively, V = constant and V = tVt, where Vt = constant. The effect of the alongshore scale of the topographic feature is examined. For small scales, adjective effects of...