Global Structure of Magnetotail Reconnection Revealed by Mining Space Magnetometer Data
Global Structure of Magnetotail Reconnection Revealed by Mining Space Magnetometer Data
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DOI：
10.1029/2022ja031066
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发表时间：
2023-01
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影响因子：
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通讯作者：
G. Stephens;M. Sitnov;R. S. Weigel;D. Turner;A. Nikolai;Tsyganenko;Anthony Rogers;K. Genestreti;J. Slavin
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文献类型：
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作者：
G. Stephens;M. Sitnov;R. S. Weigel;D. Turner;A. Nikolai;Tsyganenko;Anthony Rogers;K. Genestreti;J. Slavin
磁尾中的重连发生在沿着所谓的X线，在微观空间尺度上，磁力线撕裂并脱离等离子体（与粒子回旋半径相当）。在2017-2020年，磁层多尺度（MMS）使命探测到磁尾中的X线，使他们能够在局部尺度上进行调查。然而，这些X线的全局结构和演化对于理解它们的形成和总能量转换机制至关重要，由于观测的内在局部性和并发数据的极端稀疏性，它们几乎仍然未知。在这里，我们表明，挖掘过去26年收集的空间磁力计数据的多使命档案，然后拟合使用灵活基函数建模的磁场表示，忠实地重建X线的全球模式; 26个模型X线中有24个匹配（Bz = 0等值线在地球半径或RE的102倍内）或几乎匹配（Bz = 2 nT等值线在地球半径或RE的102倍内）的MMS遇到重连点的位置。获得的全球重联图像是在亚暴活动的背景下考虑的，包括常规亚暴和更复杂的事件。
Reconnection in the magnetotail occurs along so‐called X‐lines, where magnetic field lines tear and detach from plasma on microscopic spatial scales (comparable to particle gyroradii). In 2017–2020, the Magnetospheric MultiScale (MMS) mission detected X‐lines in the magnetotail enabling their investigation on local scales. However, the global structure and evolution of these X‐lines, critical for understanding their formation and total energy conversion mechanisms, remained virtually unknown because of the intrinsically local nature of observations and the extreme sparsity of concurrent data. Here, we show that mining a multi‐mission archive of space magnetometer data collected over the last 26 yr and then fitting a magnetic field representation modeled using flexible basis‐functions faithfully reconstructs the global pattern of X‐lines; 24 of the 26 modeled X‐lines match (Bz = 0 isocontours are within ∼2 Earth radii or RE) or nearly match (Bz = 2 nT isocontours are within ∼2RE) the locations of the MMS encountered reconnection sites. The obtained global reconnection picture is considered in the context of substorm activity, including conventional substorms and more complex events.