Tail reconnection triggering substorm onset
Tail reconnection triggering substorm onset
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DOI：
10.1126/science.1160495
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发表时间：
2008-08-15
期刊：
影响因子：
56.9
通讯作者：
Kepko, Larry
中科院分区：
文献类型：
--
作者：
Angelopoulos, Vassilis;McFadden, James P.;Kepko, Larry
磁层亚暴爆炸性地释放出以前储存在地球磁尾中的太阳风能量，包围了整个磁层，并产生了壮观的极光。目前还不清楚亚暴是由流经近地磁尾的电流中断引发的，大约是10 R-E（R-E：地球半径，或6374公里），还是由通常在磁尾更远的地方看到的磁重联过程引发的，大约是20到30 R-E。我们报告同时测量磁尾在多个距离，在亚暴发作的时候。在20 R-E时观测到了重新连接，至少在极光增强前1.5分钟，至少在亚暴扩张前2分钟，以及在近地电流中断前约3分钟。这些结果表明，亚暴很可能是由尾部重连引发的。
Magnetospheric substorms explosively release solar wind energy previously stored in Earth's magnetotail, encompassing the entire magnetosphere and producing spectacular auroral displays. It has been unclear whether a substorm is triggered by a disruption of the electrical current flowing across the near- Earth magnetotail, at similar to 10 R-E ( R-E: Earth radius, or 6374 kilometers), or by the process of magnetic reconnection typically seen farther out in the magnetotail, at similar to 20 to 30 R-E. We report on simultaneous measurements in the magnetotail at multiple distances, at the time of substorm onset. Reconnection was observed at 20 R-E, at least 1.5 minutes before auroral intensification, at least 2 minutes before substorm expansion, and about 3 minutes before near- Earth current disruption. These results demonstrate that substorms are likely initiated by tail reconnection.