Statistics of Reconnecting Current Sheets in the Transition Region of Earth's Bow Shock
Statistics of Reconnecting Current Sheets in the Transition Region of Earth's Bow Shock
复制标题
地球弓形激波过渡区重新连接电流片的统计
DOI：
10.1029/2019ja027119
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
F. Wilder
中科院分区：
文献类型：
--
作者：
I. Gingell;Steven J. Schwartz;J. Eastwood;J. Stawarz;J. Burch;R. Ergun;S. Fuselier;D. Gershman;B. Giles;Y. Khotyaintsev;B. Lavraud;P. Lindqvist;W. Paterson;T. Phan;C. Russell;R. Strangeway;R. Torbert;F. Wilder
我们已经进行了全面调查的突发模式观测地球的弓形冲击的磁层多尺度使命，以确定和表征电流片与碰撞冲击，重点是那些包含快速电子流出，磁重联的可能签名。调查表明，这些薄的电流片内观察到的磁层多尺度的突发模式数据集内的约40%的冲击的过渡区。由于只有很小的明显偏向于准平行激波方向和高阿尔文马赫数，结果表明激波处的重联是一个普遍的过程，发生在所有激波方向和马赫数上。在检查电流片属性的分布时，我们发现与冲击波的距离，片宽度或电子喷射速度之间没有相关性，尽管电子和离子喷射速度之间的关系支持该区域仅电子重联的预期。此外，我们发现，强大的加热统计是不可分离的背景波动，因此，在冲击重联的主要后果是在放松的拓扑结构的无序磁场在过渡区。
We have conducted a comprehensive survey of burst mode observations of Earth's bow shock by the Magnetospheric Multiscale mission to identify and characterize current sheets associated with collisionless shocks, with a focus on those containing fast electron outflows, a likely signature of magnetic reconnection. The survey demonstrates that these thin current sheets are observed within the transition region of approximately 40% of shocks within the burst mode data set of Magnetospheric Multiscale. With only small apparent bias toward quasi‐parallel shock orientations and high Alfvén Mach numbers, the results suggest that reconnection at shocks is a universal process, occurring across all shock orientations and Mach numbers. On examining the distributions of current sheet properties, we find no correlation between distance from the shock, sheet width, or electron jet speed, though the relationship between electron and ion jet speed supports expectations of electron‐only reconnection in the region. Furthermore, we find that robust heating statistics are not separable from background fluctuations, and thus, the primary consequence of reconnection at shocks is in relaxing the topology of the disordered magnetic field in the transition region.