Internal waves

Internal waves rely on the existence of a gradient in density and are ubiquitous in the Earth’s atmosphere and oceans. The Earth’s rotation also affects their properties (they are then properly called inertia-gravity waves).

Their behavior is strongly affected by the existence of large-scale flows. In papers 5, 7, 16, 19 and 27, we investigate how near-inertial waves, that is inertia-gravity waves with frequency near the Coriolis frequency, are affected by a background eddy field.

The tides in the Earth’s ocean lead to the generation of internal tides (i.e. internal waves at tidal frequencies) as the barotropic tide (the tide that makes the ocean surface rise and fall) flows over topography. In papers 21, 24, 30 and 31, we analyze models of this process to assess its efficiency as the slope of the topography becomes supercritical (that is, exceeds the slope of the internal waves of tidal frequency).

We have also worked on theoretical models of internal waves generated by oscillating bodies, as is the case for laboratory experiments. In paper 47, we look at generation by an oscillating tangential disc, for which viscosity is critical.

The internal tide problem is closely related to ocean mixing and in paper B1 we review processes that contribute to small-scale mixing in the ocean.

This work were supported by the European Science Foundation's TAO Programme and by NASA.  Part of it was carried out during the Geophysical Fluid Dynamics Program.