Posted on 02/17/2006 2:25:27 PM PST by blam
Atmospheric 'sprites' captured in explosive detail
18:28 16 February 2006
NewScientist.com news service
Kimm Groshong
Sprites are rare and fleeting events, lasting between just 10 and 100 milliseconds (Image: Steven A Cummer, Duke University)
Mysterious flashes of light called “sprites", that occur above thunderclouds during powerful storms, have been captured on film in unprecedented detail by researchers using an ultra-high-speed camera.
The best images yet of the flashes – which resemble a giant undulating jellyfish with its tentacles falling from a halo of light – have allowed the team to pick apart their structure and mechanics.
Sprites are fleeting events, which normally last between 10 and 100 milliseconds. The researchers hope their results will help inform models of the chemical and physical nature of the flashes.
In summer 2005, researchers from Duke University, US, and collaborators from FMA Research in Fort Collins, Colorado, US, kept a watchful eye on the skies above the Great Plains from the Yucca Ridge Field Station in Fort Collins, hoping to capture sprites in action using their 7000-frames-per-second camera. And capture it they did - watch their video in Quicktime format or RealPlayer format. Previously, the best published sprite images were recorded at 1000 frames per second.
Lightning streamers "The whole structure develops a lot in one millisecond. So by going with the faster video we really see all the pieces and how they develop in time," says Steven Cummer, assistant professor of electrical and computer engineering at Duke’s Pratt School of Engineering.
And with so much energy being pumped into a small region, Cummer says sprites may drive atmospheric chemistry that does not normally occur. "The significance at this point lies in what chemical effects these [sprites] may have on the upper atmosphere," Cummer told New Scientist.
The researchers say sprites typically begin at an altitude of about 50 miles (80 Kilometres) in the sky in single spots where the electric field creates spark. Those produce falling "streamers" that branch out as they fall. Much brighter, thicker channels follow, expanding upward from the original spots.
Natural beauty Based on the new images, the team says "isolated dots" that glow intensely and often outlast the rest of the sprite are the result of a collision of streamers. Cummer says such collisions may account for as many as half of the observed dots.
In July and August 2005, the group imaged 66 sprite events above Kansas and Nebraska. They captured their clearest images on 13 August, their final day of observations. Their findings from that event are to be posted in the online version of Geophysical Research Letters on 22 February.
"When a sprite is captured on film, it's extremely exciting," says Nicolas Jaugey, a member of Cummer's team. "You just see a flash on the TV screen, but when you retrieve the recording from the high-speed camera and see its development, it's very beautiful."
Who ya gonna call?
Goat Butters....
Sprite? They got any Nehi?
wow! what a cool video!
Probably coming to an IMAX theater near you. :-)
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If you see something that looks like a star And it's shooting up out of the ground And your head is spinning from a loud guitar And you just can't escape from the sound Don't worry too much, it'll happen to you We were children once, playing with toys And the thing that you're hearing is only the sound Of the low spark of high-heeled boys The percentage you're paying is too high-priced While you're living beyond all your means And the man in the suit has just bought a new car From the profit he's made on your dreams But today you just read that the man was shot dead By a gun that didn't make any noise But it wasn't the bullet that laid him to rest Was the low spark of high-heeled boys If you had just a minute to breathe And they granted you one final wish Would you ask for something like another chance Or something similar as this Don't worry too much, it'll happen to you As sure as your sorrows or joys And the thing that disturbs you is only the sound Of the low spark of high-heeled boys High-heeled boys . . . If I gave you everything that I owned And asked for nothing in return Would you do the same for me as I would for you Or take me for a ride And strip me of everything, including my pride But spirit is something that no one destroys And the sound that I'm hearing is only the sound Of the low spark of high-heeled boys Heeled boys . . . |
Those are cool. On another note I was listening to the radio yesterday and they were playing what sounded like a lot of static but they said it was lightening on Saturn. Which if I recall correctly they said that means there is moisture on Saturn.
I saw one of these sprites on the NBC Olympic coverage last night, but it lasted more than a few milliseconds. More like 4.5 minutes . . .
L
Heh heh....they said Cummer...
Courtesy of Stevie Windwood and Traffic.
There was one of those hovering over Farpoint Station once. A nasty temper it had too.
Probably the source of high-altitude ozone. Means the "ozone hole" was a false alarm.
These were investigated as a possible source/cause of the last shuttle crash.
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