In this study, we report observations from the Magnetospheric Multiscale (MMS) mission of large-scale parallel electric fields in a magnetosheath reconnecting current sheet. The four MMS satellites successively crossed an electron jet embedded in a broad current sheet and detected a unipolar being colocated with the jet. The strong electron pressure anisotropy inside the broad current sheet suggests that the jet could be generated by the firehose instability. The observations show that the large-amplitude can fill the entire electron diffusion region (EDR) in the magnetosheath reconnection and thus dominates electron acceleration therein, dramatically different from EDRs in the magnetotail and magnetopause where large-amplitude unipolar was rarely detected. The appearance of this could be due to the strong guide field which is common in the magnetosheath.

中文翻译：

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在磁鞘磁重联期间共位于扩展电子扩散区的大规模平行电场

在这项研究中，我们报告了磁层多尺度 (MMS) 任务对磁鞘重新连接电流片中大规模平行电场的观察结果。四颗 MMS 卫星相继穿过嵌入在宽大电流片中的电子射流，并检测到与射流共置的单极。宽电流片内的强电子压力各向异性表明射流可能是由消防水带不稳定性产生的。观察结果表明，大振幅可以填充磁鞘重联中的整个电子扩散区（EDR），从而主导其中的电子加速，这与磁尾和磁层顶中很少检测到大振幅单极的 EDR 显着不同。这个的出现 可能是由于磁鞘中常见的强导场。