Observed electric fields associated with lightning initiation
Observed electric fields associated with lightning initiation
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DOI：
10.1029/2004gl021802
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发表时间：
2005-02-11
影响因子：
5.2
通讯作者：
Rison, W
中科院分区：
文献类型：
--
作者：
Marshall, TC;Stolzenburg, M;Rison, W
现场电场（E）的测量和推断的闪电起始位置的三个云到地闪被用来确定雷暴区域中的预闪E超过阈值失控击穿。在5.77公里的高度上测得的最大E值为186 kV m（-1），相当于海平面上逃逸电子的370 kV m（-1）;这个E值近似于逃逸电子雪崩估计阈值的130%。此外，E超过失控阈值的体积估计为1-4 km（3），垂直深度约为1000 m。至少在这部分体积内，逃逸电子指数增长的特征标度高度为100 m或更小。因此，对于这三次闪光，存在逃逸击穿所需的电场条件，并且逃逸击穿可能引发闪光。
In situ electric field ( E) measurements and inferred lightning initiation locations of three cloud-to-ground flashes are used to identify a thunderstorm region in which the preflash E exceeded the threshold for runaway breakdown. The maximum measured E in the region was 186 kV m(-1) at 5.77 km altitude, which for runaway electrons is equivalent to 370 kV m(-1) at sea level; this E value is similar to130% of the estimated threshold for an avalanche of runaway electrons. In addition, the volume where E exceeded the runaway threshold was estimated to be 1-4 km(3), with a vertical depth of about 1000 m. At least within part of this volume the characteristic scale height for exponential growth of runaway electrons was 100 m or less. Thus for these three flashes the electric field conditions necessary for runaway breakdown existed, and runaway breakdown could have initiated the flashes.