A preliminary study on laser‐triggered lightning

Abstract

As a preliminary study on triggering lightning with a CO2 high‐power laser, we carried out laser‐triggered discharge experiments to investigate the necessary conditions for initiating and guiding an electrical streamer with a CO2 laser‐produced plasma channel. We found the following. (1) The necessary electric field for initiating a streamer with the plasma channel depends closely on the absorbed energy for producing the plasma channel and not on the length of the plasma channel. The higher the absorbed energy, the smaller the necessary electric field. The minimum electric field is about 200 kV/m. (2) The necessary electric field for guiding a streamer by the plasma channel is lower than that for initiating a streamer. The minimum electric field is about 170 kV/m. Furthermore, we observed the electric field at the top of a 50‐m tower and the field on the ground simultaneously during 10 Japanese winter thunderstorms. The observed results agree with theoretical calculations showing that the field at the top of a 50‐m tower is on average 2 orders larger than the field on the ground. We conclude that it is highly possible to trigger a lightning discharge if we shoot a CO2 laser‐produced plasma channel upward through the top of a high grounded tower under conditions of high thunderstorm electric fields.