1 / 7

The Rossby wave paradigm and its problems

The Rossby wave paradigm and its problems. Ian James School of Mathematics, Meteorology and Physics University of Reading. Basic properties. Transverse wave motion in a fluid with a gradient of potential vorticity Dispersion relationship: Highly dispersive; anisotropic propagation

josh
Download Presentation

The Rossby wave paradigm and its problems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Rossby wave paradigm and its problems Ian James School of Mathematics, Meteorology and Physics University of Reading

  2. Basic properties • Transverse wave motion in a fluid with a gradient of potential vorticity • Dispersion relationship: • Highly dispersive; anisotropic propagation • Basic paradigm of low frequency flow

  3. Physical picture • Displaced parcel acquires vorticity relative to environment. • “Action at a distance” x < 0 x < 0 A B x > 0

  4. Ray tracing • Packets propagate with group velocity (WKBJ) • “Refractive index” m • Pacific-North American pattern (w=0 Rossby wave)

  5. Positive feedback between trains of Rossby waves Stationary wrt each other: sheared flow, change of sign of [q]y Barotropic instability (horizontal) Baroclinic instability (vertical) Fluid instability

  6. Definition of PV gradient • Quasi-geostrophic form: • Barotropic: if then U [q]y

  7. Towards a Rossby wave programme • Rationale for smoothing of PV field? • How do Rossby waves propagate in the presence of small scale [q]yanomalies? • Scattering of Rossby waves in an inhomogeneous medium?

More Related