Topographic generation of long internal waves in a channel

Abstract

Abstract The resonant interaction between surface and internal gravity waves propagating along a uniform channel in a two-fluid system has been investigated both experimentally and theoretically. The wave coupling is induced by a shelf which runs along one side of the channel and large resonant internal waves are generated around certain frequencies. The shallow water approximation is used in the theoretical treatment of the problem and resonant frequencies and wave modes are calculated. Good experimental agreement is obtained near the resonant modes of low frequency, and the agreement deviated in the expected direction for higher frequency mode interactions. Measurements are also presented for the structure of the waves near the resonant frequencies. This is a laboratory model of a mechanism for the generation of long period internal waves in oceanic straits and channels.