Han-Tzong Su of National Cheng Kung University of Taiwan and his colleagues report in the June 25 Nature that they've observed another new type of lightning — "gigantic jets." The researchers used low-light cameras to capture images of the gargantuan electrical discharges shooting upward from the tops of thunderclouds over the south china sea. The jets ascend to the ionosphere — the charged portion of the upper atmosphere — to form vast 50-mile-tall shapes resembling carrots or trees that last less than a second. By feeding negative charge from the thundercloud to the ionosphere, the researchers believe such jets may have a strong influence on what they call "earth's global electric circuit."
—Agnieszk A. Biskup, "New Lightning Discovered," The Boston Globe, July 1, 2003
Su noted that while the other types of jets seem to occur over most parts of the world, the six gigantic optical jets observed so far have all been connected to thunderstorms over the open sea.
"It is likely that the gigantic jets are a special feature of oceanic thunderstorms," he said.
In addition to the images, Su's team used data from monitoring stations in Antarctica and Japan to show that the discharges also produced extremely low frequency radio waves that could interfere with global radio communications.
Victor Pasko, an electrical engineer at Pennsylvania State University who pioneered study of blue jets, noted in an accompanying Nature commentary that in addition to causing significant disturbances of long-range radio signals, "the ionization created by a gigantic jet is likely to have a significant chemical effect on that part of the atmosphere," although no studies have been done on such changes.
—Lee Bowman, "Some lightning jets shoot up high into atmosphere," Scripps Howard News Service, June 25, 2003
