On the Initiation of Upward Negative Lightning by Nearby Lightning Activity: An Analytical Approach

Abstract

Upward lightning occurs generally from tall structures. The mechanism of the initiation of upward lightning is not yet fully understood. Upward lightning can be classified into two categories based on either the absence or the presence of other lightning activity prior to the upward flash. This work proposes an explanation of how upward lightning flashes can be triggered by nearby lightning activity. It is generally thought that the lightning activity prior to the flash will intensify the electric field at the tip of the tall structures. However, to the best of our knowledge, no attempt has been made to evaluate theoretically this hypothesis. In this paper, we derive analytically the electric field enhancement on the ground (or at the top of tall structures) based on different triggering scenarios. These fields are later used in a simplified corona model to evaluate if they are able to trigger upward lightning. It is shown that both slow processes such as leader propagation and faster return strokes can trigger an upward negative flash from relatively short structures of a few tens of meters, even without any slowly varying background electric field. This study confirms theoretically experimental observations and it provides new insights into the mechanisms of initiation of upward flashes from tall structures.

Characteristics of Electric Currents in Upward Lightning Flashes From a Windmill and its Lightning Protection Tower in Japan, 2005–2016

“…Such sceneries are recently confirmed by the analytical research conducted by Sunjerga et al. (2021).…”

“…Schumann et al (2019) described various sceneries leading to the triggering of UL from tall structures in the USA and Brazil. Such sceneries are recently confirmed by the analytical research conducted by Sunjerga et al (2021).…”

Bidirectional Recoil Leaders in Upward Lightning Flashes Observed at the Säntis Tower

“…An illustrated summary of the observations presented in this work is shown in Figure 17. Note that we assume that the negative part of the RL is longer (see [Sunjerga, Rubinstein, et al., 2021] for more details) than the positive part, and that the positive end stops to extend at a certain point (see [Mazur et al., 2013]). The figure can be described as follows.…”

An analysis of manual and autoanalysis for submicrosecond parameters in the typical first lightning return stroke

“…The benefit of using this strategy was that it reduced local site error. The position of a lightning strike event can be obtained more accurate and reliable [50], [51].…”