Multiple states for quasi-geostrophic channel flows
Abstract
We consider nonlinear baroclinic instabilities of two-layer quasi-geostrophic flow in a rectilinear channel. The full potential vorticity equations are shown to possess a countable infinity of invariant wavenumber sets. Each set is composed of a particular pattern in wavenumber space in which many Fourier modes have zero energy. Solutions with initial conditions confined to a particular wavenumber pattern will remain forever in that pattern. There is also a general asymmetric state with non-zero energy in all wavenumbers. The final state of a long-time evolution calculation depends on initial conditions and internal stability.
- Publication:
-
Geophysical and Astrophysical Fluid Dynamics
- Pub Date:
- 1990
- DOI:
- 10.1080/03091929008208930
- Bibcode:
- 1990GApFD..54....1C
- Keywords:
-
- Baroclinic instability;
- nonlinear instability;
- channel flow