[M-IS27] Atmospheric electricity: Atmospheric electricity and climate change

[MIS27-P02] Characteristics of a thunderstorm that produced bolt-from-the-blue lightning discharge on 26 August 2018

*Takeshi Kudo¹, Namiko Sakurai² (1.OTOWA ELECTRIC CO., LTD., 2.National Research Institute for Earth Science and Disaster Resilience)

Keywords:lightning, bolt from the blue

Bolt from the blue lightning discharge (BFB) is a cloud-to-ground (CG) lightning discharge which comes out of the thundercloud. BFB is a very dangerous CG lightning discharge, because the sky is clear overhead at lightning strike point. It is important to investigate characteristics of BFB producing thunderstorms.
A BFB producing thunderstorm in north Kanto area on 26 August 2018 was confirmed by the photographs of lighting photo contest. We examined that the frequency of BFB occurrence and inclination of BFB expansion direction of the thunderstorm.
The Lightning Mapping Array (LMA) 3D lightning location data operated by National Research Institute for Earth Science and Disaster Resilience (NIED) was used to determine horizontal distance and expansion direction of BFB stepped leader. In order to identify the events of CG lighting discharge, Japanese Lightning Detection Network (JLDN) lightning data was used. XRAIN data provided by Ministry of Land, Infrastructure, Transport and Tourism (MLIT) was used to determine precipitation area (inside or outside of cloud) and moving direction of thunderstorm.
In this presentation, we will report results of the frequency of BFB occurrence and the inclination of BFB expansion direction.