线性与非线性对称不稳定的数值试验

设计了一个准二维非静力数值模式，用该模式研究了对称不稳定的发展和演变特征。线性和非线性对称不稳定的数值试验结果表明。线性和非线性对称环流的演变特征及其结构有很大差异。在基本状态是对称不稳定的情况下，线性对称不稳定在其发展过程中始终维持着向冷区倾斜的对称环流；而非线性对称不稳定在其发展初期与线性情况相同，当扰动增长到一定程度时非线性平流项的作用不可忽略，原来对称的环流则被破坏。

THE NUMERICAL RESEARCH OF SYMMETRIC INSTABILITY

A non-linear and non-hydrostatic numerical model is designd to study the development and evolution of symmetric instability. The test results show that structure and evolution of non-linear symmetric instability are very different from linear. When the basic state is symmetric instabile. in the linear symmetric instability. slantly symmetric circulations are maintained thoughout the grpwth of perturbations. However, in non-linear symmetric instability, it is very stalar with the former in early table of perturbations growing. With growth of the perturbations, non-linear interaction of advection term happens and the symmetric circulations are destroyed.