There is a strange kind of lightning, only discovered in 1989, that is purely understood. It is called SPRITE* – lightning that shoot up to space. Εlectrical discharges from the top of the clouds to the outer edges of our atmosphere and not from the bottom to the ground. They occur above thunderstorms, way above, 50-90 kilometers up, in the layer of our atmosphere we call Mesosphere, which lies above the Stratosphere! That’s strange if you consider that most clouds only reach a dozen or so kilometers in height – obviously their influence extends much further. (Feature Image Credit: University Alaska Fairbanks)
*SPRITE =
Stratospheric/mesospheric
Perturbations
Resulting from
Intense
Thunderstorm
Electrification
Sprite lightnings are extremely fast and faint electrical discharges, but increasingly sensitive digital cameras have given us amazing photos. These mysterious bursts of light in the upper atmosphere momentarily resemble gigantic jellyfish. The red color is from exited oxygen atoms in the upper atmosphere, the same reason the aurorae sometimes glow red. See here a photo from Stephen Hummel.
Sprites are difficult to photograph because not only they are faint but they occur above thunderstorms. So you can only spot them above storms on the horizon, if you’re closer the cloud itself blocks them. Unless you have a better vantage point, above the clouds, way above, as in space. Like the next phantastic picture from ISS.
ISS view of a red sprite at the far right above a thunderstorm. The bright object in the sky is the Moon. You can also see Orion rising over the horizon. Credit: NASA, Expedition 44
Recently, high speed videos, like the next one, are better detailing how sprites actually develop.
Sprites take place in the Mesosphere (most meteors also burn up in the mesosphere). The clouds and nearly all weather occur in the Troposphere. Credit: Randy Russell, UCAR
Space Shuttle Endeavour silhouetted against the atmosphere. The orange layer is the Troposphere, the white layer is the Stratosphere, and the blue layer is the Mesosphere. The shuttle is actually orbiting at an altitude of more than 320 km, far above all three layers. Credit: Space Station Expedition 22 Crew, NASA
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Kostas Sakkas
