Instabilities and waves on a columnar vortex in a strongly stratified and rotating fluid

Junho Park 1, * Paul Billant 1
Abstract : This paper investigates the effect of the background rotation on the radiative instability of a columnar Rankine vortex in a strongly stratified fluid. We show that a cyclonic background rotation strongly stabilizes the radiative instability. The modes become neutral when the Rossby number Ro is below a critical value which depends on the azimuthal wavenumber of the wave. In the limit of small Rossby number, there exist fast neutral waves that are not captured by the quasi-geostrophic theory. In the presence of anticyclonic background rotation, the centrifugal instability dominates the radiative instability only when -400 less than or similar to Ro < -1. The numerical stability analysis is completed by asymptotic analyses for large wavenumbers which explain the properties and mechanisms of the waves and the instabilities. The stability of a continuous smoothed Rankine vortex is also investigated. The most amplified azimuthal wavenumber is then finite instead of infinite for the Rankine vortex. (C) 2013 AIP Publishing LLC.
Complete list of metadatas

Cited literature [25 references]  Display  Hide  Download

https://hal-polytechnique.archives-ouvertes.fr/hal-00996422
Contributor : Denis Roura <>
Submitted on : Tuesday, May 27, 2014 - 3:32:06 PM
Last modification on : Wednesday, March 27, 2019 - 4:39:25 PM
Long-term archiving on : Wednesday, August 27, 2014 - 10:43:02 AM

File

1.4816512.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Junho Park, Paul Billant. Instabilities and waves on a columnar vortex in a strongly stratified and rotating fluid. Physics of Fluids, American Institute of Physics, 2013, 25 (8), pp.086601. ⟨10.1063/1.4816512⟩. ⟨hal-00996422⟩

Share

Metrics

Record views

229

Files downloads

264