Loading...
Date
2026-05-01
Abstract
We examine scattering of waves by a vortex under the f-plane approximation. Two kinds of vortices are considered: eddies (where the angular velocity decreases monotonically with radius) and rings (where the angular velocity peaks at a certain radius before decaying). Both kinds can reflect more energy than the incident wave carries, but over-reflection by eddies is relatively weak, whereas that by rings can be infinitely strong (hyper-reflection). The difference is attributed to stronger or weaker centrifugal force and other curvature-related effects. It is also shown that a hyper-reflecting flow is always marginal to a range of unstable flows, but the converse does not hold: flows that are unstable at frequencies lower than the minimum frequency of inertia-gravity waves cannot radiate; hence, do not hyper-reflect. Finally, we derive an asymptotic model for the coupled dynamics of a vortex and a spectrum of small-amplitude random waves. It is shown that, if the vortex hyper-reflects a certain wavenumber and this wavenumber is present in the spectrum, hyper-reflection almost immediately drains a significant proportion of the vortex’s energy
Supervisor
Description
Publisher
AIP Publishing
Citation
Physics of Fluids 38(5), 054102
Collections
Files
ULRR Identifiers
Funding code
Funding Information
Sustainable Development Goals
External Link
License
Attribution-NonCommercial-ShareAlike 4.0 International