对称扰动与纬向基流的相互作用 II.粘性波包的发展与弥散

Interactions between Symmetric Disturbance and Zonally Basic Flow Part II: The Development and Dispersion of the Viscosity Wave Packet

该文对对称扰动与纬向基流的相互作用理论进行了深入的研究。这里是该文的第二部分，主要讨论粘性波包的发展与弥散。在对称扰动波包的动力学方程组中引进粘性作用（Ｐｒ＝１）可以发现，粘性耗散及扩散导致了“虚群速度（Ｃｉｇｙ，Ｃｉｇｚ）”的产生，它对波包的发展有着比较重要的影响。此外，各种稳定度参数的时空变化对扰动波包的发展具有重要作用。在一定的条件下，还可以产生波包的不稳定现象。

The present paper has comprehensively studied the problems of the interactions between symmetric disturbance and zonally basic flow. Here is its Part II. Mainly dealing with the development and dispersion of the viscosity wave packet. It is found by introducing viscosity ( Pr =1) into the dynamic equations of symmetric disturbance wave packet that the dissipation and diffusion of viscosity lead to the producing of “imaginary dispersion velocity ( C i gy , C i gy ) ” which has a great effect on development of wave packet. The spacial and temporal changes of each kind of stability parameter play an importand role in development of the disturbance wave packet. The phenomenon of instability of wave packet may be produced on some conditions.