Eddies and Waves: "Internal-Wave Generation by Tide-Topography Interacti..." by Prof. Dr. Kevin Lamb

Описание: February 14, 2023

Eddies and Waves: "Internal-Wave Generation by Tide-Topography Interac- tions in the Presence of Background Currents" by Prof. Dr. Kevin Lamb (University of Waterloo, Canada).

Abstract:
Internal wave generation by tide-topography interactions have been the subject of many studies in recent decades, most of which ignore the effects of steady background currents. Background currents can modify the wave generation process in several ways. Horizontal shear modifies the effective Coriolis frequency. Both this and horizontal variations in the stratification in geostrophic balance with the current change the criticality of the bottom slope. Variations in the effective Coriolis frequency can result in wave trapping and create blocking regions. It can also result in the creation of regions susceptible to parametric subharmonic instability if the effective Coriolis frequency is reduced to less that half the tidal frequency. Vertically shear background currents flowing across a ridge create asymmetries in internal wave propagation on either side of the ridge and are accompanied by critical layers. In this talk I will present numerical simulations illustrating these process using two-dimensional numerical simulations of internal wave generation at ridge and shelf like topography in the presence of cross-topography or along topography background currents.