The interaction between transpolar arcs and cusp spots
The interaction between transpolar arcs and cusp spots
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DOI：
10.1002/2015gl066194
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发表时间：
2015-11
影响因子：
5.2
通讯作者：
R. Fear;S. Milan;J. Carter;R. Maggiolo
中科院分区：
文献类型：
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作者：
R. Fear;S. Milan;J. Carter;R. Maggiolo
跨极弧和尖点都是行星际磁场偏北时出现的极光现象。跨极弧与磁尾中的磁重联有关，它关闭磁通量并导致闭合磁通量的“楔形”，这些闭合磁通量仍然被捕获并嵌入磁尾叶中。尖点是高纬磁层顶波瓣重联的指示;在最简单的情况下，波瓣重联重新分配开放通量，而不会导致磁层开放通量含量的任何净变化。我们目前的观察两种现象的相互作用，即，在其部分寿命期间与尖点相交的跨极弧。这一观测的意义在于叶重联可以产生打开闭合磁尾通量的效应。我们认为，这样的事件不应该是罕见的。
Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a “wedge” of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high‐latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting—i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare.