Titre/Title : On the interaction of an internal wavepacket with its induced mean flow and the role of streaming
Contact : Chantal Staquet (Equipe MEIGE)
Résumé/Abstract : We consider three-dimensional gravity—inertia internal wavepackets in the form of beams with nearly monochromatic profile and discuss the coupled nonlinear interaction with their induced mean flow. This mean flow comprises : (i) an inviscid, purely modulation-induced component ; and (ii) streaming, associated with the production of mean potential vorticity via the combined action of dissipation and nonlinearity. The latter can have a profound effect on the beam profile by causing cross-beam refraction, transverse broadening and increased along-beam decay, in qualitative agreement with laboratory experiments (Bordes 2012).