Quantification of the troposphere-to-ionosphere charge transfer in a gigantic jet

Gigantic jets are the clearest manifestation of direct electrical coupling between tropospheric thunderstorms and the ionosphere. They are leaders that emerge from electrical breakdown near the top of thunderstorms and extend all the way to the lower edge of the ionosphere near 90 km altitude. By contrast, blue jets and other related events terminate at much lower altitudes. Gigantic jets have been observed from the ground and from orbit. Some seem to be consistent with an upward-propagating negative discharge of 1,000 to 2,000 C km total charge moment change, but others have not been connected to distinguishable electromagnetic signatures. Here we report simultaneous low-light video images and low-frequency magnetic field measurements of a gigantic jet that demonstrate the presence and dynamics of a substantial electric charge transfer between the troposphere and the ionosphere. The signatures presented here confirm the negative polarity of gigantic jets and constrain the lightning processes associated with them. The observed total charge transfer from the thunderstorm to the ionosphere is 144 C for the assumed channel length of 75 km, which is comparable to the charge transfer in strong cloud-to-ground lightning strokes. © 2009 Macmillan Publishers Limited. All rights reserved.

Duke Scholars

Author Steven A. Cummer Electrical and Computer Engineering