磁暴主相的經度不对称性

太阳带电粒子流通过磁边界层的中性点或阻塞点,由于极化电場的漂移运动或雷萊-泰勒（Rayleish-Taylor）不稳定运动,穿透磁层而进入地磁場被輻射带所捕获。这些被捕获的电子将向东漂移而形成西向电流。在它們围繞地球一周形成封閉的电流环以前,由于地球的自轉以及这个电流弧对地球各地的相对位置的不同,电流分布以及它在地面磁赤道附近所产生的磁場分布都将是不均匀的,对經度来耕是不对称的。本文假定电子繞地球的漂移周期为两天,計算了当磁暴开始时位于地方时00,06,12及18小时的台站記录的磁場随“暴时”T_st变化的曲线。理論結果与用佘山及洪伽幼地磁台站得到的統計結果是一致的。

LONGITUDINAL ASYMMETRY OF THE MAIN PHASE OF THE GEOMAGNETIC STORM

By the mechanism of drift motion of polorized electric field the electrons of the solar wind may penetrate into the magnetosphere through the neutral point. These electrons trapped in the geomagnetic field will drift eastward, carrying a westward electrical current. Before these electrons drift a closed cycle around the earth, the distribution of electrons and consequently the current and the magnetic field recorded at the earth surface of the equatorial region will be asymmetrical with respect to local time. In the present investigation, we have calculated the variation of magnetic field as a function of storm time Tst recorded at observatories located at 00~h, 06~h, 12~h and 18~h local time. Here we assumed that the period of electron drift around the earth is two days. Theoretical result coincides fairly well with statistical curves obtained from the long series data from Zo-Se and Huancayo Observatories.