SINE-GORDON EQUATION AS A MODEL FOR A RAPIDLY ROTATING BAROCLINIC FLUID

Recent work has shown that the Sine-Gordon and SIT equations describe the evolution of the envelope of baroclinic wave packets in a two-layer rapidly rotating fluid. The significance of this result is discussed with reference to the optical SIT problem and it is shown how this type of rotating fluid behaves in a simple way as a two-level pseudospin system. The periodic behaviour of the Sine-Gordon equation which is more appropriate for experimental situations is discussed. Experimental and numerical evidence suggests that recurrence of initial states occurs; behaviour which is strikingly similar to the FPU problem of solid state physics. © 1979 IOP Publishing Ltd.