Terrestrial gamma ray flash (TGF) observations made by the Atmosphere-Space Interaction Monitor (ASIM) have demonstrated that these TGFs are accompanied by a prominent optical pulse from a hot leader channel. It is hard to confidently resolve the true sequence of the events in the source region due to temporal proximity of the involved processes. Here we report a bright long duration TGF together with its associated optical recordings showing clear temporal separation between the TGF and the optical pulse. In this observation the optical pulse is clearly distinct and subsequent relative to the TGF. The corresponding lightning discharge occurred at the very end of the TGF. We conclude that the current surge inside the lightning leader channel cannot be responsible for generation of this TGF. The current surge that produced the associated optical pulse can itself be conditioned by the TGF and may be responsible for the TGF termination.

中文翻译：

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在 ASIM 观测中识别 TGF 和导流脉冲


大气-空间相互作用监测器 （ASIM） 进行的地面伽马射线闪光 （TGF） 观测表明，这些 TGF 伴随着来自热导流道的突出光脉冲。由于所涉及的进程在时间上接近，因此很难自信地解析源区域中事件的真实顺序。在这里，我们报告了一个明亮的长持续时间 TGF 及其相关的光学记录，显示了 TGF 和光脉冲之间的清晰时间分离。在这个观察中，光脉冲相对于 TGF 明显不同且随后。相应的雷电放电发生在 TGF 的最后。我们得出结论，雷电 leader 通道内的电流浪涌不能导致此 TGF 的产生。产生相关光脉冲的电流浪涌本身可以由 TGF 调节，并且可能是 TGF 终止的原因。