急始型磁暴的初步定性估計

本文通过下述模型来探讨典型的磁暴发生过程:当点爆炸球面波自太阳上爆发后,太阳微粒流随即以冲激波形式越过行星际空间到达地球,在地球附近可能形成驻激波面,然后微粒流由地磁空穴的中性点进入磁层,在地球周围生成电流环,产生磁暴主相。在质子与地球附近上空中性氢原子发生电荷交换的过程中,磁暴过程相应地由主相转入恢复期,在不考虑行星际空间磁場的条件下,计算出在太阳爆炸波发生后第17时、24时、32时开始的磁暴发展过程曲线,并由观测资料推测出中性点的等效面积,计算结果指出:爆炸波愈强,主相愈大,恢复期愈短,这和观测到的粒子流速度愈大,磁暴也愈强、恢复期也愈短的现象是一致的。

A QUALITATIVE MODEL OF GEOMAGNETIC STORM WITH SUDDEN COMMENCEMENT

The process of the geomagnetic storm is studied by using the following qualitative model. The solar flare being taken as an explosion, the resulting corpuscular stream will propagate through the planetary space in the form of a shock wave, and penetrate into the magnetosphere through the neutral points. The ring current thus formed by the solar wind in the equator plane is responsible for the main phase of geomagnetic storm. By charge exchange of the protons with the neutral hydrogen atoms in the outersphere, the total energy of the penetrated particles gradually decreases when the storm is in its recovery period. According to different travel times of 17h, 24h and 32h respectively of the shock wave, the storm-time magnetic variations on the earth surface are estimated which coincide with the observed facts.