Ⅰ型彗尾中MHD波的特征分析

ANALYSES AND FEATURE OF MHD WAVES IN TYPE-Ⅰ COMETARY TAILS

本文根据Ⅰ型彗尾的背景材料，分析了MHD波的色散关系，探讨了螺旋波的稳定性及其演变的特征．根据初始条件的不同，有的彗尾中可以产生稳定的螺旋波，有的则不然，只能是浑云状态．文章给出了理论推演，列出了观测结果，理论和观测能较好地符合．可进一步结合Hale－Bopp彗星的观测，进行对比和检验．

In this paper, the dispersion relation of MHD waves is analysed for Type-Ⅰcometary tails. The instability of helical waves and its evolution features are studied.In terms of different initial conditions, stable helical waves or irregular clouds may exist in different cometary tails. There is a good consistence between theoretical deduction and observational records. Further research for comet Hale-Bopp may be done based on this work.