普洱地区午夜之后电离层F_2层增层现象的初步分析

Preliminary investigation of post-midnight stratification of F_2 layer in Puer area

为了研究产生午夜之后电离层F_2层增层现象的可能物理机制,基于云南省普洱地区(E101.05°,N22.70°)电离层垂测站的观测数据,采用了频高图固定探测频率回波分析方法即iso-frequency分析法,分析了频高图中不同频率回波虚高的变化趋势和特征。结果表明,该地区午夜之后出现的F_2层增层现象和重力波存在一定的联系。此外,顶层电离层或等离子体层的等离子体向下扩展也有助于F_2层增层现象的产生。

To study the possible mechanism of the post-midnight stratification of F2 layer, this paper uses the iso-frequency method to study characteristics of variation of different frequencies echoes based on ionograms recorded in Puer area （101. 05°E, 22. 70° N） of Yunnan province. The results show that the post-midnight stratification of F2 layer is mostly due to gravity waves. Addi-tionally, plasma＇s downward diffusions from topside ionosphere or plasmasphere are also contributed to the formation of the stratification of F2 layer during post-midnight.