Paris, December 19-20th, 2001
Chantal
Staquet
Interactions of inertia-gravity waves with a barotropic shear flow We investigate the interaction of an inertia-gravity wave packet with a barotropic dynamical barrier, by means of three-dimensional direct numerical simulations of the Boussinesq equations in a rotating reference frame. A simple model is used for the barrier, namely a barotropic shear layer with a horizontal shear. We show that the increase of the intrinsic frequency of the wave packet by Doppler shifting may result in the breaking of the wave packet, in the neighbourhood of a trapping plane where the intrinsic frequency matches the Brunt-Vaisala frequency. The breaking process results in a turbulent diffusive transport of mass and momentum across the barrier when the barrier is inertially unstable. |