APOD: Jumping Sundogs Over Thunderclouds (2011 Nov 08)

[APOD Robot]

Jumping Sundogs Over Thunderclouds

Explanation: What's happening above those clouds? In the past few years, videos have appeared on the web detailing an unusual but little known phenomenon: rapid light changes over clouds. Upon inspection and contemplation, a leading hypothesis for its cause has now emerged. In sum, this hypothesis holds that a lightning discharge in a thundercloud can temporarily change the electric field above the cloud where charged ice crystals were reflecting sunlight. The new electric field quickly re-orients the geometric crystals to a new orientation that reflects sunlight differently. In other words, a lightning discharge can cause a sundog to jump. Soon, the old electric field may be restored, causing the ice crystals to return to their original orientation. To help this curious phenomenon become better studied, sky enthusiasts with similar jumping or dancing sundog videos are encouraged to share them.

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[Beyond]

I've never seen moving sun dogs before. But t'wernt much color in them thar dogs.

[Barry Vincent]

Fascinating ,but how come the clouds don't seem to be moving ?
One would think that over the duration of the video there would be some change
in the cloud shapes.

[cketter]

Fascinating ,but how come the clouds don't seem to be moving ?
One would think that over the duration of the video there would be some change
in the cloud shapes.

The clouds are moving from the top of the screen to the bottom, parallel to the roof overhang.

Very interesting explanation/hypothesis. I love physics.

Chris

[TheoricienQuantique]

Ok I think a good 20% of us thought of it (though not seriously) so I am going to say it : UFO using CLOACKING TECHNOLOGY.

[saturn2]

The electric field above the cloud change.
It produce the sundogs.
The geometric crystals change and it produce reflects sunlight differently.

[RonDavis]

A related phenomenon is that often during a thunderstorm, after a nearby lightning stroke, the rainfall suddenly becomes more intense. I figure that's because the raindrops are carrying negative charge down to the ground, building up positive charge in the clouds. The drops fall against that field, as makes sense because they are increasing the energy in the electric field. A lightning stroke between sky and ground drains off some of that charge and reduces the field, thus causing the drops to fall faster. Since a typical change in the electric field can have that much effect on many tonnes of water, I can well believe that it can rapidly affect the orientation of ice crystals in a cloud.

[Indigo_Sunrise]

Several years ago I saw something similar, but since it was rather later in the afternoon and I wasn't sure I was seeing what was really happening, I attributed it to a bit too much


This is really interesting that someone caught it on video, because I've tried several times to describe what I had seen, but everyone pretty much said the same thing: 'you're just seeing things'.
Which I guess I was, I just didn't understand what and didn't describe/explain it very well. But at least now, I can share this video and give a better idea of what I saw.

Anyway, pretty great AVOD!

[geckzilla]

Freaky. I will pay closer attention to sun dogs, now. I avoided it in the past figuring they don't change and it wouldn't be worth my vision to stare at them for longer.

[Wackybaby]

Does anyone know at what altitude do sundogs form.

I wonder at what altitude the Solar Dynamics Observatory launch passed through the sundog here.

The sonic boom effect looks just like a stone thrown into a pond.

http://www.youtube.com/watch?v=SsDEfu8s1Lw

[wizardmike]

We do know that lighting goes up. I remember seeing light (I think there're called "sprits") from space. Maybe this is happing to these clouds. Just a guess.

[Ledon]

This is not a picture. Maybe there should be an AVOD. When videos are posted to APOD I get an error in the Android app and the wallpaper does not update.

[neufer]

Click to play embedded YouTube video.

[orin stepanek]

I guess I never paid any attention to sundogs when there are thunder clouds! This is the typw of sundogs I usually notice!

Click to view full size image

[Casper]

Nonsense. it's ghosts I tell ya

[JohnD]

Wow!

Follow that back to YouTube and some related videos show things that could be similar.
See this one:

Click to play embedded YouTube video.

And it's "Sprites" of course, both blue and red:

Click to play embedded YouTube video.

John
(Thanks for the advice, Art!)
(PS turn the sound down - there's no commentary and the music is just silly. Except for the bit about spites that 'pop'.)

[Psnarf]

Gotta be space monkeys!

We're just beginning to explore the phenomena at the top of a lightning bolt. Who knew gamma rays would shoot up and travel along the Earth's magnetic field lines (whistlers), or its interaction with the ionosphere. When I was a child, nobody knew about Schumann Resonance between the ground and the ionosphere which allows us to detect lightning strikes anywhere in the Northern Hemisphere. I think there's something even trans-equatorial going on. Then there's that anomaly in the South Atlantic.

--
Obquote:
"Ad hoc, ad hoc,
and quid pro quo.
So little time,
So much to know!" -J. Hillary Boob, Phud.

[neufer]

John (who isn't as good as Art in posting full videos!

Try going back and editing using the youtube (or vimeo) button

[Cyber_3]

Wow! I have never seen this before, amazing to have caught it on video. While I am not disputing the whole lightning theory, to me, it really looks like there is a tornado on top of that cloud changing location on top of the cloud so that sometimes from our angle on the ground we see it and sometimes we don't but because of the ice crystals it makes sundogs from some angles/configurations with respect to the camera's location. I admit I don't know much about tornadoes and I've never heard of them occurring between different cloud levels as opposed to with the ground but I've seen quite a few waterspouts and that's exactly what they look like and how they move.

Just my n00b two cents.

[abrigatti]

Wow - being the viewer, recorder and owner of this video - I am really touched to see it build the interest from those in the know. The reason I recorded it is exactly for the reason I knew was going to happen - people 'doubt' what I saw, so luckily I had my iPhone to hand I posted it on youtube to try to find a plausible reason, and I must admit the most recent posts - including your outline seems - absolutely spot on. Was very strange but I am appreciative of you guys helping me get some answers to the question I originally posed

Oh and here's a second clip of the same effect, about 1-2 minutes before the main one which is getting the hits. I uploaded this a few days afterwards, but didn't seem to get the views - but the effect actually shows up more...probably before the darker storm clouds rose above covering the 'effect'.

http://www.youtube.com/watch?v=hJokSDCSePQ

Thanks again

[oldastronomer]

WAY COOL! It's not very often that APOD actually teaches us something new--or at least something we didn't know before. Keep up the great work.

[Cyber_3]

Man, that video you just posted is even more spectacular than the originating one. Aren't phones with cameras great? Now you don't have to wish you'd brought your camera, because it's always with you ^_^. There's still so much we don't understand about the weather, it's beautiful, mysterious, and yet so daunting all at the same time. I'm really looking forward to an explanation for this phenomenon.

[swallace]

It's like a natural version of a liquid crystal display! Awesome!

[Chris Peterson]

Is the bright spot in the video actually a sundog (that is, a reflection from aligned ice crystals, 22° from the Sun), or a reflection from an isolated patch of ice crystals? I've seen both (but not dancing), and since I can't tell where in this image the Sun actually is, I can't tell if this is really a sundog.

I'd think that in general, if you were interested in this phenomenon, you'd want to look for reflective areas around thunderclouds, not usually at sundogs (which aren't usually present when there are thunderclouds).

[sOnIc]

Yea thats crazy, amazing more examples haven't been captured .. . but is the significance the fact that your sundog appears to be visually right on top of a big thunder cell? Looks like a high altitude stack. Was that cloud producing lightning? And that makes it rarer? How often do you get a sundog placed directly on top of an active thunderstorm?