Force‐free field inside a toroidal magnetic cloud
Force‐free field inside a toroidal magnetic cloud
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环形磁云内的无力场
DOI：
10.1029/2003gl017692
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发表时间：
2003
影响因子：
5.2
通讯作者：
M. Vandas
中科院分区：
文献类型：
--
作者：
E. Romashets;M. Vandas
给出了任意长宽比圆环内无作用力磁场的解析解。导出了一个标量方程，该方程在求解时给出了环形坐标下的矢量场的解的核心，以超几何函数的闭合形式表示。该解可用于解释行星际空间的磁云测量。如果假设磁云是一个根植于太阳的大环圈，那么它的一部分可以局部地视为环状结构的一部分。米勒和特纳[1981]提出的前一种解决方案仅限于较大的长宽比。在环面宽高比很大的情况下，所给出的解与Lundquist[1950]对于圆柱云的解是一致的。
An analytical solution of force‐free magnetic fields inside a toroid with an arbitrary aspect ratio was found. A scalar equation was derived which when solved gives the heart of the solution of the vector field in toroidal coordinates, in closed form in terms of hypergeometric functions. The solution can be used for interpretation of magnetic cloud measurements in the interplanetary space. If it is assumed that a magnetic cloud is a large loop with roots at the Sun, then its part can be locally treated as a part of a toroid. The former solution by Miller and Turner [1981] was limited only to larger aspect ratios. The presented solution coincides with the Lundquist [1950] one for cylindrical clouds in case of a very large aspect ratio torus.