Phys.org August 8, 2022
Occasionally, lightning will exit the top of a thunderstorm and connect to the lower edge of space, forming a gigantic jet. An international team of researchers (USA – Georgia Institute of Technology, research org., Texas Tech University, University of New Hampshire, Duke University, University of Oklahoma, Los Alamos National Laboratory, Spain) reports on observations of a negative gigantic jet that transferred an extraordinary amount of charge between the troposphere and ionosphere (∼300 C). It occurred in unusual circumstances, emerging from an area of weak convection. As the discharge ascended from the cloud top, tens of very high frequency (VHF) radio sources were detected from 22 to 45 km altitude, while simultaneous optical emissions (777.4 nm OI emitted from lightning leaders) remained near cloud top (15 to 20 km altitude). This implies that the high-altitude VHF sources were produced by streamers. The streamer discharge activity can extend all the way from near cloud top to the ionosphere. The simultaneous three-dimensional radio and optical data indicate that VHF lightning networks detect emissions from streamer corona rather than the leader channel, which has broad implications to lightning physics beyond that of gigantic jets…read more. Open Access TECHNICAL ARTICLEÂ
Thunderstorm charge structure observed from VHF and radar data. Credit: SCIENCE ADVANCES, 3 Aug 2022, Vol 8, Issue 31