The generation and propagation of internal gravity waves in a rotating fluid

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Abstract
On the basis of a series of experiments in a 2×5 m tank containing a two‐layer salt‐stratified fluid mounted on the large rotating table at the University of Grenoble, we observe and attempt to explain the internal wave motions created by a moving bottom topography, which is oscillated to simulate barotropic tidal flow. We have found that when the flow over the obstacle is very supercritical, the initial wave field is quite asymmetric in plan form but evolves toward a more symmetric shape as time progresses. Large velocities are created along the crests of the waves, and these appear to scale with 2ΩAλ, where Ω is the rotation rate, A the nondimensional wave amplitude, and λ the wave width. When the flow is only slightly supercritical, the transverse velocities are correspondingly smaller, and the wave field approaches the symmetric plan form found by Maxworthy (1979) for the nonrotating case. For our particular combination of stratification and obstacle shape, two major wave systems evolve from two initial pulses created by the obstacle motion. There are of solitary wave type and during the course of the experiments are seen to evolve, combine, and form a series of finite amplitute waves ordered by amplitude. Rotation appears to have little effect on this evolutionary process but does initially affect the wave plan form and amplitude distributions.

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