The study of the instability of the meridional flow: Part 1

The present study is conducted in the equivalent barotropic model to study the stability of meridional wind at 200 mb level in tropics during summer. The equivalent barotropic model, which was introduced by Wiin-Nielsen 1 for midlatitude, is accepted for tropics after some possible changes. The meridional wind is found to be equivalent to a number of superposed dispersive Rossby waves, so the stability problem of meridional flow reduces to the stability problem of Rossby waves. In the present study, the stability of single Rossby wave is tested with a perturbation which gives zonal wind. It is found that the short Rossby waves are unstable, so the short Rossby waves release their kinetic energy to the zonal wind. Thus, the short waves of the spectral meridional flow release their kinetic energy to the zonal wind. For midlatitude, Lorenz's problem regarding the instability of Rossby wave is improved using the equivalent barotropic model