The theory of the first phase of a geomagnetic storm
The theory of the first phase of a geomagnetic storm
复制标题
地磁暴第一阶段的理论
DOI：
10.1029/te045i003p00245
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发表时间：
1940
影响因子：
--
通讯作者：
V. Ferraro
中科院分区：
文献类型：
--
作者：
S. Chapman;V. Ferraro
给出了离子和电子的均匀中性电离分布的运动和电磁场的精确解（除了忽略位移电流之外），该离子和电子最初位于无限长的圆柱表面上，并在存在处处与轴平行且强度随着距轴的距离的立方倒数而变化的永久磁场的情况下径向向内投影到圆柱体的轴。结果表明，如果总离子（或电子）电荷超过某一下限，离子和电子将保持“统一”，也就是说，将继续位于一个圆柱表面上；将会产生感应电流，在圆柱表面流动并增加圆柱内的磁场强度。该问题的讨论部分说明了磁暴的第一阶段，特别是 H 在短短几分钟内突然增加；它清楚地表明，当中性电离流进入磁场中强度不断增加的区域时，如果流足够密集，离子和电子之间的静电引力可以使电子向前移动，远远超出它们单独所能达到的距离。
An exact solution is given (apart from the neglect of displacement-currents) for the motion and electromagnetic fields of a uniform neutral ionized distribution of ions and electrons initially situated on an indefinitely long circular cylindrical surface, and projected radially inwards towards the axis of the cylinder, in the presence of a permanent magnetic field which is everywhere parallel to the axis, and varies in intensity as the inverse cube of the distance from the axis. It is shown that the ions and electrons will remain “united,” that is to say, will continue to lie on one cylindrical surface, if the total ionic (or electronic) charge exceeds a certain lower limit; an electric current will be induced, flowing round the cylindrical surface and increasing the magnetic intensity within the cylinder. The problem is discussed as one which partly illustrates the first phase of a magnetic storm, and, in particular, the sudden increase of H, during only a few minutes; it clearly shows that when a neutral ionizing stream advances into regions of increasing intensity in a magnetic field, the electrostatic attraction between the ions and electrons can carry the electrons forward far beyond the distances they could attain alone, if the stream is sufficiently dense.