Internal Waves

Internal waves: Tides and oceanic turbulence

The continuously, stably-stratified ocean supports internal gravity waves. Depending on the nature of the ocean's stratification (the vertical rate of change of the density field), these waves propagate obliquely through the ocean (when the stratification is more or less uniform) or horizontally (when the stratification is concentrated in a thin layer). In either case they transport energy and momentum 'elsewhere'. This energy may become remotely available for mixing.
It is speculated that these waves may thus play an important role in maintaining the large-scale, deep circulation, by providing downward mixing of heat. Their mixing may also be relevant for sustaining deep living communities, by providing nutrients to the water column. Because of their fairly persistent nature this applies in particular to the two most important contributant: internal tides (internal waves of tidal period) and near-inertial waves (internal waves of period close to the local inertial period). Particular items that are studied concern: the effects of geometry : e.g. in a 2D stratified channel almost all channel vertical cross-sectional shapes lead to focusing of these waves on particular limiting orbits: wave attractors the geophysical-relevant analog case of inertial waves (waves restored by Coriolis forces in a rotating homogeneous fluid) observations of deep solibores (violent short-duration events) occurring over a sloping bottom that dominate sediment-resuspension observations of spectral signatures of deep internal tides and near-inertial waves effects of non-uniform stratification on internal tide propagation observations of internal tidal beam and its numerical modeling A summarizing description of contributions to this topic can be… …downloaded as PDF-document ( ~1.7 MB). _______________