Does the atmospheric radioactivity induce lightning discharge?

2016 Fiscal Year Final Research Report

• Project/Area Number: 26550035
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Risk sciences of radiation and chemicals
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Torii Tatsuo 国立研究開発法人日本原子力研究開発機構, 福島研究開発部門 廃炉国際共同研究センター, 特任参与 (20421795)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 雷放電 / 制動放射線 / 逃走電子 / 雷雲 / 航空機観測

Outline of Final Research Achievements

In order to investigate the atmospheric electric effect that radiation provides to the lightning discharge, we investigated the structure of the long burst and the short burst observed on the ground at the time of lightning activity and characterized the features. We also observed the fluctuation of radiation from the sky at the time of lightning activity using JAXA's aircraft ”Hisho”, but no significant variation was observed. Meanwhile, we observed the fluctuation of radiation inside and around the thunderclouds by a meteorological sonde equipped with two kinds of GM tubes, and as a result, it was found that the count rate of radiation rises near the altitude of 5 to 8 km above the thundercloud. In addition, as a result of Monte Carlo calculation on the behavior of radiation with the electric field　distribution modeling the charge structure estimated from the weather data of this sonde, we confirmed that the electron density rapidly increases in the upper positive charged layer.

Free Research Field

環境放射線