Interactions and instabilities of barotropic and baroclinic rossby waves in a rotating, two-layer fluid

摘要

Barotropic and baroclinic Rossby waves in a two-layer fluid on a #x3B2;-plane can interact with each other, and are unstable for all values ofM=UK2/#x3B2;, whereUis the velocity amplitude of the particular wave, andKis its wavenumber modulus. The direction of energy transfer depends upon the pseudo-wavenumber, here defined as the square root of the sum of the square of the wavenumber and the inverse square of the radius of deformation of the mode; if a wave loses energy, some goes to smaller pseudo-wavenumbers as well as larger pseudo-wavenumbers. This contrasts with Fjortoft's conclusion that the direction of energy transfer in a homogeneous two-dimensional fluid is to larger and smaller wavenumbers.