Bifurcations and instabilities in rotating two-layer fluids: I.f-plane

A. F. Lovegrove (1) , I. M. Moroz (2) , P. L. Read (1)

1 AOPP - Department of Atmospheric, Oceanic and Planetary Physics [Oxford]
2 MI - Mathematical Institute [Oxford]

In this paper, we show that the behaviour of weakly nonlinear waves in a 2-layer model of baroclinic instability on an f-plane with varying viscosity is determined by a single, degenerate codimension three bifurcation. In the process, we show how previous studies, using the method of multiple scales to derive evolution equations for the slowly varying amplitude of the growing wave, arise as special limits of the general evolution description. A companion study will extend the results to a ?-plane.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Sciences de la Terre

A. F. Lovegrove, I. M. Moroz, P. L. Read. Bifurcations and instabilities in rotating two-layer fluids: I.f-plane. Nonlinear Processes in Geophysics, 2001, 8 (1/2), pp.21-36. ⟨hal-00302000⟩