On transport across a barotropic shear flow by breaking inertia-gravity waves

Chantal Staquet (1) , Gaël Huerre

1 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

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 Ω of the wave packet by Doppler shifting may result in the breaking of the wave packet, in the neighborhood of a trapping plane where Ω=N(N is the Brunt–Väisälä frequency of the fluid and is constant in the present study). The breaking process triggers a turbulent diffusive transport of mass and momentum across the barrier, with a turbulent Prandtl number of order 1.

Domaines: Mécanique des fluides [physics.class-ph]

Chantal Staquet, Gaël Huerre. On transport across a barotropic shear flow by breaking inertia-gravity waves. Physics of Fluids, 2002, 14, pp.1993-2006. ⟨10.1063/1.1476303⟩. ⟨hal-00264604⟩