根据VLF的相位变化确定D层宇宙线强度变化的可能性

银河宇宙线是电离层D层的重要电离源之一,它的急剧变化会使D层电子密度发生改变,从而影响VLF波的夜间传播。本文根据在西安接收英国GBR台的VLF波（16kc/s）的相位变化,讨论了在有宇宙线暴（Forbush下降）和强磁暴时,中纬D层电子浓度的变化和相应的VLF波的相位漂移;并根据VLF的相位变化,估计了相应的宇宙线强度变化。由于D层中的宇宙线强度变化通常难于观测,通过VLF波的相位漂移来估计它,这是很有意义的。所以,VLF波的传播效应可能成为间接探测宇宙线强度变化的有用工具。

THE POSSIBILITY OF THE INTENSITY VARIATION OFGALACTIC COSMIC RAYS IN THE IONOSPHERICD-REGION DETERMINED FROM THEVLF PHASE CHANGES

Galactic cosmic ray is one of the important ionization sources in the ionospheric D-region. When the intensity of galactic cosmic rays varies abruptly the electron density in the D-region could be changed and could influnce the propagation of VLF wave at nighttime. Using the recorded phase data of VLF wave （16 kc/s） transmitted by GBR （England） we have obtained the VLF phase drift and the electron density change in the D-region in the mid-latitude during the galactic cosmic ray storms （Forbush decrease） and the strong geomagnetic storms. From the VLF phase change we have determined the corresponding amplitude of Forbush decrease and storm time increase. Usually it is difficult to measure the intensity variation of cosmic rays in the D-region. The propagation effect of VLF wave could become a useful tool of detecting the intensity variation of cosmic rays.