Discovered in the early 1990s, sprites, jets and elves,
also referred to as “Transient Luminous Events (TLEs)” are flashes of
optical emissions in the stratosphere and mesosphere above severe thunderstorms.
These “fireworks” include Earth’s largest electrical discharges reaching from the
top of thunderclouds to the bottom ionosphere at 80 km altitude. Also during the
1990s, bursts of X- and gamma-rays were observed by spacecraft, from the
atmosphere above thunderstorms. These so-called “Terrestrial Gamma-ray Flashes” (TGFs)
are thought to be bremsstrahlung radiation from relativistic electrons accelerated in
the electric fields above thunderstorms. TLEs and TGFs are newly discovered processes
that couple the troposphere to the upper atmosphere and near-Earth space.
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| "On Sprites and Their Exotic Kin" by Torsten Neubert, Science, Vol 300, 2 May 2003
(see http://www.dsri.dk/cal/science-sprites.pdf) |
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