On 17 October 2016, Magnetospheric Multiscale (MMS) sampled an electron diffusion region (EDR) embedded in an electron‐scale current sheet within a mixed portion of the high‐latitude magnetosheath adjacent to the magnetopause. We analyze the generalized Ohm's law, dissipation, and electron velocity distributions inside the EDR. The velocities, magnetic fields, and densities observed in the magnetosheath and magnetosphere indicate the magnetopause was unstable to the Kelvin‐Helmholtz instability, which can form electron‐scale current sheets. Alternatively, a current sheet was observed in the solar wind at L1 40 min before the MMS observations, which could have been compressed by the bow shock initiating reconnection. Hundreds of keV particles near the EDR may have been locally accelerated.

中文翻译：

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高纬度电子扩散区的磁层多尺度观测

2016年10月17日，磁层多尺度（MMS）采样了一个电子扩散区（EDR），该电子扩散区嵌入在与磁层顶相邻的高纬度磁石混合区域中的电子尺度电流表中。我们分析了EDR内部的广义欧姆定律，耗散和电子速度分布。在磁石表面和磁层中观察到的速度，磁场和密度表明，磁成石对开尔文-亥姆霍兹不稳定性是不稳定的，可以形成电子级电流表。或者，在进行MMS观测之前的40分钟的L1时刻，在太阳风中观测到了一个电流表，该电流表可能已被船首撞击引发的重新连接所压缩。EDR附近的数百个keV粒子可能已经局部加速。