大气重力波产生中纬电离层不均匀体的理论

研究中纬电高层Ｆ区大尺度不均匀休的基本性质及其与大气重力波的关系。分析了等离子体Ｐｅｒｋｉｎｓ不稳定性的非线性发展，发现这种不稳定性饱和在很小的幅度上。讨论了Ｐｅｒｋｉｎｓ不稳定性与重力波的耦合，表明重力波能触发中纬电离层Ｆ区等离子体不稳定性。由重力波触发的等离子体不稳定性可能演变成大幅度的波形结构，空间和时间调制的不均匀体理论揭示了大尺度中纬电离层不均匀体的产生机制。关键词：

A THEORY OF MW-LATITUDE IONOSPHERIC IRREGULARITIES PRODUCED BY ATMO-SPHERIC GRAVITY WAVES

Basic properties of large scale irregularities in the rnid-latitude ionospheric F region and their relationship with atmospheric gravity waves are studied. The temporal evolution of the plasma Perkins instability is analyzed. It is found that the instability saturates at a small amplitude. The coupling between the Perkins instability and gravity waves is discussed and it is shown that gravity waves can initiate the plasma instability in the mid-latitude F region. The plasma instability initiated by gravity waves can evolve into steady-state perturbations, large amplitude wave-like structures, and spatially and temporally modulated irregularities. The theory indicates the production mechanism of the large scale irregularities in the mid-latitude ionosphere.