Initiation of Streamers Due to Hydrometeor Collisions in Thunderclouds
Initiation of Streamers Due to Hydrometeor Collisions in Thunderclouds
复制标题
DOI：
10.1029/2018jd028407
复制
发表时间：
2018-07-27
影响因子：
4.4
通讯作者：
Pasko, Victor P.
中科院分区：
文献类型：
--
作者：
Cai, Qiheng;Jansky, Jaroslav;Pasko, Victor P.
为了在雷暴条件下启动拖缆和引导器，电场应达到高于临界击穿电场E-k的值(即类似于30千伏cm(-)(1).atm(-)(1))。而气球测得的雷暴最大电场约为6-9kV·cm(-1)·atm(-1)。在本工作中，为了实现流光启动所需的电场放大，研究了一个由两个接近的球形水流星组成的系统。流光起始是由描述E-k以上电场中电子倍增的Meek数确定的。我们找到了在这两个粒子之间的缝隙中，以及当两个粒子通过放电通道连接时，在两个粒子系统的外周，成功地启动流光的粒子半径之间的关系。此外，我们使用文献中提供的三个真实的水流星大小模型分布来估计流光起始的频率，并且发现只有在3和6公里高度上相对较高的电场>；=0.5E(K)时，才有可能在外周发生流光起始。
In order to initiate streamers and leaders under thunderstorm conditions the electric field should reach values higher than the critical breakdown field E-k (i.e., similar to 30 kV.cm(-)(1).atm(-)(1)). However, the maximum electric field in thunderstorms measured by balloons is similar to 6-9 kV.cm(-1).atm(-1). In present work, to achieve the electric field amplification required for streamer initiation, a system of two approaching spherical hydrometeors is investigated. Streamer initiation is determined from a Meek number, describing electron multiplication in fields above E-k. We have found the relationships between radii of particles for successful streamer initiation in the gap between these two particles and also on the outside periphery of the two particle system when the particles are connected by a discharge channel. Furthermore, we estimated the frequency of streamer initiation using three realistic hydrometeor size model distributions available in the literature and found that the scenario of streamer initiation on the outside periphery is only possible for relatively high electric fields >= 0.5E(k) at altitudes of 3 and 6 km.