Propagation of near-inertial oscillations through a geostrophic flow

Clicks: 1
ID: 292884
1997
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal

Ranked #654 of 1,397 articles by views in journal of marine research

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 1,397 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
The method of multiple time scales is used to obtain an approximate description of the linear propagation of near-inertial oscillations (NIOs) through a three-dimensional geostrophic flow. This 'NIO equation' uses a complex field, M(x, y, z, t), related to the demodulated horizontal velocity by M z = exp (if 0 t)(u + iv), where f 0 is the inertial frequency. The three processes of wave dispersion, advection by geostrophic velocity and refraction (geostrophic vorticity slightly shifts the local inertial frequency) are all included in the formulation. The NIO equation has an energy conservation law, so that there is no transfer of energy between NIOs and the geostrophic flow in the approximation scheme. As an application, the NIO equation is used to examine propagation of waves through a field of smaller scale, geostrophic eddies. The spatially local ζ/2 frequency shift, identified by earlier WKB calculations (ζ is the vertical vorticity of the geostrophic eddies), is not expressed directly in the wave field: the large-scale NIO samples regions of both positive and negative ζ so that there is cancellation. Instead, the ζ/2 frequency shift is rectified to produce an average dispersive effect. The calculation predicts that an NIO with infinite horizontal scale has a frequency shift -Kf 0 m 2 /N 2 where K is average kinetic energy density of the geostrophic eddies, m the vertical wavenumber of the NIO, f 0 the inertial frequency and N the buoyancy frequency. Because of the dependence of the frequency shift on m 2 , there is an effective vertical dispersion, whose strength is proportional to the eddy kinetic energy. This process greatly increases the vertical propagation rate of synoptic scale NIOs.
Reference Key
openalex_W2009928161 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors W. R. Young, Mahdi Ben Jelloul
Journal journal of marine research
Year 1997
DOI
10.1357/0022240973224283
URL
https://doi.org/10.1357/0022240973224283
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.