Open magnetic flux and magnetic flux closure during sawtooth events
Open magnetic flux and magnetic flux closure during sawtooth events
复制标题
DOI：
10.1029/2008gl036374
复制
发表时间：
2008-12
影响因子：
5.2
通讯作者：
B. Hubert;S. Milan;A. Grocott;S. Cowley;J. Gérard
中科院分区：
文献类型：
--
作者：
B. Hubert;S. Milan;A. Grocott;S. Cowley;J. Gérard
我们使用IMAGE‐FUV极地极光观测和SuperDARN雷达网络的电离层对流测量来研究文献中先前报道的几个锯齿状事件。我们估计了在这些锯齿状间隔的相当一部分时间内地球磁层中开放磁通量的量以及磁通量的打开和关闭速率，即昼侧和夜侧重联速率。我们发现，在锯齿状间隔期间，由于太阳风在这些间隔期间携带了强烈的南向国际货币基金组织，磁层高度加载了开放通量。磁层试图通过一系列的亚暴扩张放松到一个负荷较低的结构。然而，这些亚暴并不一定演变到它们的结束之前，夜侧重联的再次加强是对白天磁层持续负荷的响应。
We use IMAGE‐FUV observations of the polar aurora and measurements of the ionospheric convection from the SuperDARN radar network to study several sawtooth events previously reported in the literature. We estimate the amount of open magnetic flux in the Earth magnetosphere during a significant part of these sawtooth intervals as well as the magnetic flux opening and closure rates, that is, the dayside and nightside reconnection rates. We find that during the sawtooth intervals the magnetosphere is highly loaded with open flux as a result of the strongly southward IMF carried by the solar wind during these intervals. The magnetosphere tries to relax to a less loaded configuration through a sequence of substorm expansions. However, these substorms do not necessarily evolve to their end before reintensification of nightside reconnection occurs in response to continued loading of the magnetosphere on the dayside.