COLLISION INTERACTIONS OF SOLITONS IN A BAROCLINIC ATMOSPHERE

In this paper the interactions between two marginally unstable barocli nic wave packets in the two-layer Phillips model are investigated by u sing the multiple-scale method. It is shown that the interactions can be described by a set of two coupled nonlinear Schrodinger equations. Except for two special cases the equations have only four invariants o f motion and cannot be solved by the inverse scattering method. The eq uations are solved numerically to study the collision interactions bet ween two solitons. It is found that; though the coefficients in the eq uations are fixed, the behavior of the two solitons may be quite diffe rent, which is closely related to the initial states of the two solito ns (the speeds and the amplitudes of the solitons well before the inte ractions). For some initial conditions the collision interactions may be soliton-like in that the properties of the two solitons change very little, while for other initial conditions some ''inelastic'' phenome na are observed: one soliton may be destroyed by the other, or two sol itons may change their speeds and directions of propagation and fuse i nto a new bound state.