Starship Asterisk*

Sprite Lightning in Slow Motion

Explanation: What causes sprite lightning? Mysterious bursts of light in the sky that momentarily resemble gigantic jellyfish have been recorded for over 25 years, but their root cause remains unknown. Some thunderstorms have them -- most don't. Recently, however, high speed videos are better detailing how sprites actually develop. The featured video is fast enough -- at about 10,000 frames per second -- to time-resolve several sprite "bombs" dropping and developing into the multi-pronged streamers that appear on still images. Unfortunately, the visual clues provided by these videos do not fully resolve the sprite origins mystery. They do indicate to some researchers, though, that sprites are more likely to occur when plasma irregularities exist in the upper atmosphere.

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I found the Wikipedia description and explanation helpful to understanding this phenomena. You might look it up.

I wish the video had been made longer by looping it.....so you did not have to restart it all the time.

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Boomer12k wrote:I wish the video had been made longer by looping it.....so you did not have to restart it all the time.

Interwebs provide.
http://www.infinitelooper.com/?v=i3StAXEbGSM&p=n

Liquid lightening? I assume that Sprites never make it anywhere close to the ground. It would seem to not be a good thing to be caught in.

Any record of aircraft flying through sprites?

Maybe they're caused by some type of high energy particle impacting the upper layers of the atmosphere? Also I'd be very happy if Chris Peterson responded to my post, that guy's awesome!

starsurfer wrote:Maybe they're caused by some type of high energy particle impacting the upper layers of the atmosphere? Also I'd be very happy if Chris Peterson responded to my post, that guy's awesome!

I am not Chris, but I try answer anyhow High energy particles don't cause lightning but extensive air showers. The most energetic (and most rare) particles have energies about 100 times higher than can be accelerated by our particle accelerators LHC and can lead to an "avalanche" of secondary particles that span thousand square kilometers. On the low energy end, energetic particles are ejected from the Sun and cause aurorae.

There was a very nice Nova tv episode about sprites and a successful attempt to simultaneously record one from two widely spaced aircraft. From the data they captured they where able to produce a 3D rendering.

starsurfer wrote:Maybe they're caused by some type of high energy particle impacting the upper layers of the atmosphere? Also I'd be very happy if Chris Peterson responded to my post, that guy's awesome! :D

Regrettably, I have little to add on this matter. I agree with the most awesome Markus, however, that sprites are not related to high energy particles in the atmosphere. I expect the actual mechanism is not all that complex in broad principle, even if the details likely are (due to the complexities of plasma physics).

To further Markus's comment about high energy cosmic rays, those at the top end have about the same kinetic energy as a 100 mph baseball pitch. They are very, very rare, which is a good thing. You don't want to get hit by one of those!

(I had the good fortune a few weeks ago to stand just meters away from the particle collision point in the ATLAS detector of the LHC at CERN. Secondary particles from those collisions fly through tens of meters of solid detectors. Just thinking about a particle with 100 time that energy is mind boggling. But not sprite producing.)

Chris Peterson wrote:(I had the good fortune a few weeks ago to stand just meters away from the particle collision point in the ATLAS detector of the LHC at CERN. ...)

At CERN?? You sure do get around. You must be a very 'spritely' fellow.

(Better check your lepton count. Are you still glowing?)
I did not know that sprites propagate downward. Do elves behave in the same manner? Lightning storms remain mysterious. Allowing for the permittivity of wet air, there isn't enough of a charge differential to account for ground strikes. Charge carriers can be snow or ice crystals caught in powerful updrafts. I vaguely recall the rule-of-thumb for temperature vs altitude is about 3.5 degrees Fahrenheit per thousand feet. At 100-degrees on the ground, the freezing point is only about 20Kft AGL. With updrafts pushed upward twice that distance, things get pretty cold near the top of a cumulo-nimbus cloud, the top of the anvil pretty much defined by the tropopause. I suspect that the ionosphere could be an easier target for lightning from the top of the cloud than the ground vs the bottom.
There are more things in heaven and earth, than are dreamt of in my philosophy, as the Bard of Avon might have put it, were I in conversation with Hamlet instead of Horatio.

It almost looks like something is dripping from space into the upper atmosphere then fragmenting into smaller subunits. It does appear like some process akin to particle physics. I hope we continue to learn more about sprites; they seem quite fascinating. Thanks for the primer.

BDanielMayfield wrote:There was a very nice Nova tv episode about sprites and a successful attempt to simultaneously record one from two widely spaced aircraft. From the data they captured they where able to produce a 3D rendering.

As Bruce said, the NOVA did a good job showing off the science being done on this topic. Found here

Also makes me curious if we have any capability to look for sprites on other bodies in the solar system on which lightning occurs. Seems like they are difficult enough to detect here.

If you encounter a cross-site-scripting error trying to watch the flash movie at pbs.org, there is a 720p copy at
https://www.youtube.com/watch?v=4-3ZmNF35sw
where you will also find lots of space-related NOVA episodes.