Challenge for short-term prediction of lightning discharge by monitoring charge and discharge of an isolated thundercloud

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18795
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 25:Social systems engineering, safety engineering, disaster prevention engineering, and related fields
• Research Institution: Komatsu University (2022); Ashikaga University (2021)
• Principal Investigator: Yamashita Kozo 公立小松大学, 生産システム科学部, 准教授 (20609911)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 雷雲 / 雷 / 静電界 / フィールドミル / スローアンテナ / IoT

Outline of Final Research Achievements

In this study, we have developed a methodology for a quantitative estimation of an electrostatic charge inside a thunderstorm before a lightning discharge to realize the short-term lightning prediction. We had succussed to calculate point charges assumed inside a thundercloud quantitatively based on the multipoint measurement of electrostatic field on the ground with two types of electrostatic sensors which had been originally designed. We had analyzed only an isolated thundercloud in which a simple charge structure could be assumed. By applying dipole or tripole charge models inside thunderclouds, temporal variation for heights and amounts of cloud-charges inside an isolated cloud had been estimated with 1 second resolution. Initial results indicated the possibility for the short-term prediction of lightning discharges by detecting a characteristic temporal change of cloud-charges before lightning occurrences.

Free Research Field

大気電気学

Academic Significance and Societal Importance of the Research Achievements

独自開発した多点計測用静電界センサー２種を用い、特定の条件を満たした雷雲に対して「充電」と「放電」の１秒分解能での定量評価に成功した。これらの成果は、落雷に至る雷雲の帯電評価による落雷警報システムの設計・開発に役立つ。また、地上静電界の多点計測に基づいた雷雲電荷の特徴的変化の抽出より、落雷直前予測の可能性を示唆する結果を得た。同手法の簡易化・一般化は、雷害をもたらす落雷の直前発生予測法確立に繋がるものと考えられる。