[A-OS11] Ocean Mixing Frontiers

[AOS11-01] Tide-topography interactions with a background sheared current: critical layers and asymmetric internal wave breaking

*Kevin Lamb¹ (1.University of Waterloo)

Keywords:Internal waves, Tide-topography interactions, Critical layers, Wave-breaking

Internal wave generation by tide-topography interactions has been the subject of many studies in recent decades. Many of these studies have considered the generation of internal waves over a two-dimensional symmetric ridge in the absence of steady background currents. In this situation, waves propagating to the left and right of the ridge are the same. This symmetry is broken in the presence of steady background currents. In this talk, the effects of a uni-directional steady background current confined to lie above a ridge will be discussed. The background current introduces asymmetries in the characteristics of the leftward and rightward propagating waves. If the current is strong enough, then critical layers are present on one side of the ridge for low mode waves that further modify the wave field. The implications for wave breaking and mixing will be discussed.