Abstract. Lightning properties of a total of 1174 negative downward lightning flashes are analyzed. The high-speed video recordings are taken in different regions around the world, including Austria, Brazil, South Africa and USA, and are analyzed in terms of flash multiplicity, duration, interstroke intervals and ground strike point (GSP) properties. Although the results vary among the data sets, the analysis reveals that a third of the flashes are single-stroke events, while the overall mean number of strokes per flash equals 3.67. From the video imagery an average of 1.56 GSPs per flash is derived, with about 60 % of the multiple stroke flashes striking ground in more than one place. It follows that the channel creating a GSP is re-used by a factor of 2.3. Multiple-stroke flashes last on average 371 ms, whereas the geometric mean (GM) interstroke interval value preceding strokes producing a new GSP is about 18 % greater than the GM value preceding subsequent strokes following a pre-existing channel. In addition, a positive correlation between the duration and multiplicity of the flash is presented. The characteristics of the subset of flashes exhibiting multiple GSPs is further examined. It follows that strokes with stroke order of two create a new GSP in 60 % of the cases, while this percentage quickly drops for higher order strokes. Further, the possibility to form a new channel to ground in terms of the number of strokes that conditioned the previous channel shows that approximately 88 % developed after the occurrence of only one stroke. Investigating the time intervals in the other 12 % of the cases when two or more strokes re-used the previous channel showed that the average interstroke time interval preceding a new channel is found to be more than twice the time difference between strokes that follow the previous channel.

中文翻译：

---

负的向下闪电中的全球地面触击点特性–第1部分：观测

摘要。分析了总共1174个负向下闪电的闪电属性。高速视频记录是在世界各地（包括奥地利，巴西，南非和美国）拍摄的，并根据闪光多次性，持续时间，中风间隔和地面打击点（GSP）特性进行了分析。尽管各数据集的结果有所不同，但分析显示，闪光的三分之一是单笔划事件，而每次闪光的总平均笔划数等于3.67。从视频图像中，平均每次闪光可获取1.56 GSP，其中约60％的多次笔画闪光会在一个以上的地方撞击地面。因此，创建GSP的渠道被重复使用2.3倍。多冲程闪光平均持续371毫秒，而产生新GSP的笔画之前的笔画几何平均间隔时间值大约比已有通道之后的笔画之前的GM值大18％。另外，呈现了持续时间和闪光的多重性之间的正相关。表现出多个GSP的闪光子集的特征将得到进一步检查。因此，在60％的情况下，笔划顺序为2的笔划会创建一个新的GSP，而对于较高顺序的笔划，此百分比会迅速下降。此外，就调节前一个通道的笔划数而言，形成新的接地通道的可能性表明，仅发生一个笔划后，约有88％的土地发育。