The evolution characteristic of nonlinear Rossby wave in the real basic flow II: The energy and structure evolution of Rossby wave and the effect of the initial field on it

By using our difference formula and the fitted basic flow function, we investigate the evolutions of stream field structure and total energy of quasigeostrophic barotropic linear and nonlinear Rossby waves and the relation between the perturbed initial filed and the evolution of relative total energy of Rossby wave. The numerical experiments demonstrate that the relative total energy of linear or nonlinear wave increases or decreases by oscillation. The oscillatory period of nonlinear Rossby wave is much less than that of linear Rossby wave. The nonlinear term not only restrains the energy rapid increasing but also restrains the energy rapid decreasing. The structure of linear Rossby wave will always keep the standard trigonometric wave during its evolution, while the structure of nonlinear Rossby wave will evolve to elliptic cosine wave from the standard trigonometric wave of initial value during its evolution and there will be the adjusted long-wave phenomenon for nonlinear Rossby wave. The evolution of nonlinear Rossby wave depends on the initial value and the structure of basic flow intensely and there may appear the phenomenon similar to chaos.