Atmosphere Ocean Science Friday Seminar

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Wave scattering in an eddy field

Speaker: Nick DeFilippis

Location: Warren Weaver Hall 1314

Date: Friday, November 15, 2024, 4 p.m.

Synopsis:

Observations of the oceanic internal wave energy frequency spectrum reveal a peak in the near-inertial band and a power law in the super-inertial range. Although the mechanism behind this spreading is still unclear, recent numerical results suggest that wave energy injected in the near-inertial band is spread to higher frequencies through scattering by the balanced eddy field. Theoretical work finds that unsteady balanced flows produce frequency spreading via an ‘induced diffusion’ of wave modes to higher wavenumbers in a rotating shallow water setting.
We cover the basics and fundamentals behind these results. We outline the raytracing approach and how it can be used to represent a wave-field in wave-mean flow interactions. We explore frequency spreading using numerical simulations using an unsteady background flow in a low-Froude regime. Finally, we outline some useful data analysis methods.