We present a comprehensive statistical study of magnetic holes, defined as localized decreases of the magnetic field strength of at least 50%, in the solar wind near Mercury, using MESSENGER orbital data. We investigate the distributions of several properties of the magnetic holes, such as scale size, depth, and associated magnetic field rotation. We show that the distributions are very similar for linear magnetic holes (with a magnetic field rotation across the magnetic holes of less than 25°) and rotational holes (rotations >25°), except for magnetic holes with very large rotations (≳140°). Solar wind magnetic hole scale sizes follow a log‐normal distribution, which we discuss in terms of multiplicative growth. We also investigate the background magnetic field strength of the solar wind surrounding the magnetic holes, and conclude that it is lower than the average solar wind magnetic field strength. This is consistent with finding solar wind magnetic holes in high‐β regions, as expected if magnetic holes have a connection to magnetic mirror mode structures. We also present, for the first time, comprehensive statistics of isolated magnetic holes in a planetary magnetosheath. The properties of the magnetosheath magnetic holes are very similar to the solar wind counterparts, and we argue that the most likely interpretation is that the magnetosheath magnetic holes have a solar wind origin, rather than being generated locally in the magnetosheath.

中文翻译：

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汞附近太阳风中的磁孔和磁石场

我们使用MESSENGER轨道数据，对水星附近太阳风中的磁孔进行了全面的统计研究，磁孔的定义是至少50％的磁场强度局部降低。我们研究了磁性孔的几个属性的分布，例如刻度尺寸，深度和相关的磁场旋转。我们表明，线性磁孔（跨磁孔的磁场旋转小于25°）和旋转孔（旋转> 25°）的分布非常相似，除了旋转非常大（≳140° ）。太阳风磁孔尺度的大小遵循对数正态分布，我们将根据乘性增长进行讨论。我们还研究了围绕磁孔的太阳风的背景磁场强度，得出的结论是它低于平均太阳风磁场强度。这与在高如磁孔与磁镜模式结构的连接所预期的那样，β区域。我们还首次提出了行星磁石中孤立磁孔的综合统计信息。磁石场磁孔的性质与太阳风对应物非常相似，我们认为最可能的解释是，磁石场磁孔具有太阳风起源，而不是在磁石场中局部产生。