February 10, 2016: SFB754 Colloquium

16:00 h, large conference room, GEOMAR, Düsternbrooker Weg 20

Abstract:

Tide-topography interactions are the source of approximately half the internal wave energy in the ocean, with wind forcing being the other dominant generation mechanism. Tide-topography interactions can generate internal waves in a variety of forms including internal wave beams and internal solitary waves. 

Internal waves have the interesting property that the direction of propagation of internal plane waves in the vertical-horizontal plane is determined by their frequency. This gives rise to critical reflection when waves reflect off a slope which is aligned with the direction of energy propagation of the reflected wave (i.e., internal wave energy propagates parallel to the sloping boundary). In inviscid linear theory as the slope becomes critical the amplitude of the reflected wave becomes infinite: nonlinear and viscous effects must become important. In the context of tide-topography interactions near-critical slopes (critical to internal waves of tidal frequency) are important generation sites. Near critical slopes are very common in the world’s oceans and in fact internal wave generation has been conjectured to help shape the continental slope.

In this talk I begin with a general overview of some of the many interesting properties of internal waves including critical reflection from a slope. The generation of internal wave beams and internal solitary waves will be described and the importance of near-critical slopes for internal wave generation will be discussed. I will finish with an application to wave generation along the Peruvian Shelf. 

Contact:
Dr. Christiane Schelten