Cloud-to-ground strokes, narrow bipolar events, and energetic in-cloud pulses are known classes of high peak-current lightning processes that occur in thunderstorms. Here, we report one more distinct class of high peak-current events observed exclusively over mountainous terrain, usually above 2,000 m altitude, in the continental Unites States. These events, which we call mountain-top energetic pulses (MEPs), are bipolar pulses with negative radiated field polarities. MEPs are generated between the high mountain tops and compact overhead thunderclouds. Evidence supports the hypothesis that MEPs are produced by terrain-initiated upward positive leaders propagating in high electric fields due to the proximity of the low negative charge regions of the thunderstorms. This scenario further suggests the possibility that MEPs are associated with downward terrestrial gamma-ray flashes, and their high peak currents imply that they may produce elves.

中文翻译：

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雷暴中山区上空的一类独特的高峰值电流闪电脉冲

云对地冲击、窄双极事件和高能云内脉冲是雷暴中发生的高峰值电流闪电过程的已知类别。在这里，我们报告了另一种截然不同的高峰值电流事件，仅在美国大陆的山区，通常海拔 2,000 米以上。这些事件，我们称之为山顶高能脉冲 (MEP)，是具有负辐射场极性的双极脉冲。MEP 生成在高山顶部和紧凑的头顶雷云之间。证据支持以下假设，即 MEP 是由地形引发的向上正先导产生的，由于雷暴的低负电荷区域靠近，它们在高电场中传播。