Data from: Indirectly measured ambient electric fields for lightning initiation in fast breakdown regions

We report a new approach to measure indirectly the ambient thunderstorm electric fields in fast positive breakdown regions. For a given geometry of the discharged fast breakdown region, we show that there is a minimum ambient electric field required to produce a given charge moment change. We apply this approach to the fast breakdown measurements for two events reported by (Rison, 2016) and find that the average ambient electric field in the discharged region is at least 1.0-1.5 \times 10^5 V/m at the 9.5 km initiation altitude of these events. This electric field is close to the runaway electron avalanche electric field and to the critical field for positive streamer propagation. These measurements provide a meaningful starting point for more detailed analyses or simulations of what occurs inside the fast breakdown process that is responsible for the initiation of at least some lightning discharges.

本研究提出一种间接测量快速正击穿区域内雷暴环境电场的新方法。针对给定的已放电快速击穿区域几何构型，本研究证明，若要产生特定的电荷矩变化，需满足最小环境电场阈值。我们将该方法应用于Rison等人（2016）报道的两起事件的快速击穿测量分析，结果显示，在这些事件的9.5 km起始高度处，已放电区域内的平均环境电场至少为1.0×10^5 ~1.5×10^5 V/m。该电场数值与逃逸电子雪崩电场以及正流光传播的临界电场数值相近。本次测量结果可为针对至少部分闪电放电起始相关的快速击穿过程内部物理机制的精细化分析与模拟研究提供有价值的初始参考依据。