Interactions Between Mesoscale Barotropic And Baroclinic Components

In the mesoscale dynamic model, by applying the vertical mean operator and vertical disturbance operator, we decompose the atmosphere to barotropic and baroclinic components in an attempt to investigate interactions between them. Three parts are discussed: (1) the dynamical mechanism in the conversions between mesoscale barotropic and baroclinic components, in which we discuss the conversions between barotropic and baroclinic components by using the E-P theory,,and try to offer theoretical referrers for exploring the mesoscal dynamic form a new aspect. (2) the theory on instability development of baroclinic components, in which we mainly deal with the function of viscosity to symmetric baroclinic wave packet under different mediums and stabilities by comparing the case of viscosity and inviscid. It is found that the dissipation and diffusion of viscosity lead to the producing of "imaginary dispersion velocity ". In special and temporal changes of the meridional gradients with the barotropic components of zonal flow and potential temperature play an important role in development of the disturbance wave packet. (3) On the problem of nonlinear symmetric instability in zonal shear of barotropic components. By using the equations of adiabatic, inviscid, nonlinear symmetric disturbance and a multi-scale singular perturbation technique, we discuss the limited amplitude characteristics of unsteady wave, and find that the limited amplitude of unsteady wave exhibits an periodic variation.