Subsurface Signature of a Reflecting Internal Wave Beam

We examine the subsurface signature of an internal wave beam reflecting off a free-slip slip top surface in a linearly stratified water column using 3-D direct numerical simulations. A spectral multidomain penalty scheme in the vertical enables finer resolution of the subsurface region. The wave beam is modelled based on a recently obtained characterization of the internal wave field radiated by a stratified turbulent wake of a towed sphere. Subsurface current and strain fields are quantified as a function of beam geometry, steepness and phase-line-tilt angle with respect to the vertical. We also compute the induced surface displacements and discuss the potential of nonlinear harmonic generation.