Nature Geoscience, published online 23 August 2009; doi: 10.1038/ngeo607
Quantification of the troposphere-to-ionosphere charge transfer in a gigantic jet
Steven A. Cummer1, Jingbo Li1, Feng Han1, Gaopeng Lu1, Nicolas Jaugey1, Walter A. Lyons2 and Thomas E. Nelson2
Abstract
Gigantic jets are the clearest manifestation of direct electrical coupling between tropospheric thunderstorms and the ionosphere. They are leaders1, 2, 3 that emerge from electrical breakdown near the top of thunderstorms4 and extend all the way to the lower edge of the ionosphere near 90-km altitude5. By contrast, blue jets6 and other related events7, 8 terminate at much lower altitudes. Gigantic jets have been observed from the ground5, 9, 10 and from orbit11. Some seem to be consistent with an upward-propagating negative discharge of 1,000-2,000 C km total charge moment change 9, but others have not been connected to distinguishable electromagnetic signatures10. 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 jets4 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.
²FMA Research, Inc., Yucca Ridge Field Station, Fort Collins, CO 80524, U.S.A.
*Correspondence: Steven A. Cummer1 e-mail: cummer@ee.duke.edu
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