The response of a continental shelf to travelling pressure disturbances

Abstract

Assuming a rectangular model of a continental shelf, this paper sets out to calculate the response of the shelf and ocean regions to plane atmospheric pressure disturbances travelling with constant speed in a longshore direction.

It is shown that, for a sinusoidal disturbance, there is resonance at a given speed of propagation c only if c lies between the speeds of long waves on the shelf and ocean regions, and then only if the wave number of the disturbance matches one of the possible modes of long waves trapped on the shelf.

In addition, the passage of a pressure front along the shelf is modelled by a step function, and the response to such a disturbance is calculated in closed form. If the speed of the disturbance is between the speed of long waves in the shelf and ocean regions, then there is a wake of trapped long-wave modes, the amplitudes of which may be quite large compared with the change in the atmospheric pressure.