Static Buildup/Discharge within Funnels?

[Jason Harris]

Anything more recent than this 1999 attempt?
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Fortune was with the researchers that day and the F4 moved almost exactly between two of the turtles. To the researchers surprise, they saw the electric field dipped, and no lightning as recorded.

Hunyady said that lack of electrical activity may be due to lofted debris reducing the electric field, or possibly to increased conductivity inside the tornado itself.

http://science1.nasa.gov/science-news/science-at-nasa/1999/essd16jun99_1/

This is interesting too:
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"These tornadoes from a couple weeks ago were probably the most videotaped tornadoes in history. If you just watched the video, there's almost no lightning," Marshall said.

Visible lightning, that is. In fact, as Marshall explained, there actually was lightning, a whole lot of it, in the storm that caused the Moore tornado. It's just that most of it didn't hit the ground and was thus unseen by humans.

Earth Network's "Total Lightning Network" saw it, though. That's because this network, which consists of about 600 stations across the United States, has instruments that can track in-cloud lightning, the flashes that occur within a cloud and never make it to the ground.
[. . .]
"That Moore tornado ... that particular tornado went from no lightning and really no storm to like 50 flashes per minute," Marshall said. "It's a very classic scenario where you have a significant rise in lightning well in advance of the tornado."

On May 20, when the tornado hit Moore, his network saw its first spike in lightning to around 33 flashes per minute at 2:13 p.m., which is when it would issue a warning

At 2:35, the in-cloud lightning hit 50 flashes per minute. The tornado touched down in Newcastle, Okla., at 2:56.

http://www.scientificamerican.com/article/could-lightning-provide-earlier-tornado-warnings/

 

[MClarkson]

All due respect here, but we do not have hundreds or thousands of photos or videos, or eyewitness accounts that show the inside of a funnel.

It is not realistic to think that much lightning, with its giant length and somewhat erratic paths, could possibly remain hidden within a funnel at all times. And its not just pictures. The EM radiation emitted by lightning could not universally fail to be detected by modern lightning networks.

There is no reason to think that lightning chooses condensation funnels significantly more or less than a similar volume of air nearby.

 

[Dan Robinson]

The TIV video from last year is probably the best inside-a-tornado video we have - and it clearly shows what you can see inside of a large tornado - that is, *nothing*. For an observer to be able to see lightning in that environment, it's going to have to be very intense, which would also make it visible from the outside. At least dimly.

If clouds were conductive, lightning would never happen - there would never be a way for opposing charges to build up, as they'd just "leak" between regions of charge.

The one way I could see tornadoes indirectly triggering lightning is by lofting debris at least 1,000 feet into the storm. Objects inside of storms at that altitude or higher can act as leader trigger/nucleation points, much as aircraft and tall towers sometimes do. That is, a small piece of sheet metal could 'trigger' leader initiation for a CG lightning flash that may have otherwise happened at a slightly different location in the storm.

 

[rdale]

Truman, the length of your posts, the disjointed sentences, the weird capitulation, the lack of referenced materials, and missing evidence all make your claims seem pretty invalid.

 

[TrumanBoyer]

Truman, the length of your posts, the disjointed sentences, the weird capitulation, the lack of referenced materials, and missing evidence all make your claims seem pretty invalid.

I did mention that I was not trying to write a novel, and just throwing out some facts, and food for thought.
Writing style should not be judged as evidence. I have a lot to share on the subject, and not so much time.

I am not trying to make any claims, except that electrostatic discharge is not only possible, but likely, within a funnel,
and that it would be more like St. Elmo's Fire, not brilliant discharges like CG lightning.

This would explain why "funnel lightning" (St Elmo's is a type of lightning) would not be seen often from outside the funnel.

More food for thought...

http://www.srh.noaa.gov/oun/?n=events-19550525-stormelectricity

MODS -- If I am getting out of hand please let me know. I get a little excited sometimes. Not much else to do this year.... LOL.

-T

 

[TrumanBoyer]

The TIV video from last year is probably the best inside-a-tornado video we have - and it clearly shows what you can see inside of a large tornado - that is, *nothing*. For an observer to be able to see lightning in that environment, it's going to have to be very intense, which would also make it visible from the outside. At least dimly.

If clouds were conductive, lightning would never happen - there would never be a way for opposing charges to build up, as they'd just "leak" between regions of charge.

The one way I could see tornadoes indirectly triggering lightning is by lofting debris at least 1,000 feet into the storm. Objects inside of storms at that altitude or higher can act as leader trigger/nucleation points, much as aircraft and tall towers sometimes do. That is, a small piece of sheet metal could 'trigger' leader initiation for a CG lightning flash that may have otherwise happened at a slightly different location in the storm.

Good Observations. That TIV video is probably the best we have, but still not too great, and I am sure it is not representative of all tornadoes.
If we are talking about the same video.

Clouds are poor conductors, but conduct much better than air, that's why a funnel cloud can form a discharge path for the parent cloud.

Intra-cloud water droplets hold charge, charge builds in the more turbulent parts of the storm, and discharges like a capacitor when the charge balance
between different areas within the cloud reach a threshold. In the case of a CG strike, the funnel could become a path of least resistance.

A debris cloud could become a path for a ground leader. I find that your 1000 ft requirement is questionable.
30-50 meters is cited as usual length of a ground leader.

Dust devils form strong electric fields, I am sure that a debris cloud could as well.
It would, of course, have the same electric charge as the ground.



-T

 

[Dan Robinson]

1000-2000 feet AGL is a favored area for the initiation point of the CG discharge (bi-directional leader). The upward ground leader initiates close to the ground in response to final stages of the stepper leader descending.

It's a good thought, but cloud droplets/crystals are what *become charged* within a cloud. In that sense the droplets/crystals are non-conductive objects that become charged, similar to a balloon that gets charged by rubbing it on wool. Lightning doesn't follow neutral cloud material (for example, we don't see bolts always following the leading edge a shelf cloud down to the ground), but charged regions of clouds aloft can allow the lightning to continue to propagate.

 

[Kirk Chestnut]

I step away from the computer for just a few days and find this subject has "sparked" quite a bit of interest. Thank you all the commentary. You did not disappoint.

Yes, Lee Sandlin's "Storm Kings" cites several historical observations of lights within funnels. We enjoy a knowledge base today that folks 100 years ago let alone 50 did not have. Probably most of those observers did not fully grasp what they were seeing. I just could not remember hearing (or seeing) any contemporary observations of the like.

 

[Kirk Chestnut]

For those who have read Storm Kings or know the Irving, KS story, my family and I conducted our pilgrimage there yesterday amid threatening clouds. It is worthy of a thread itself.

 

[joel ewing]

I don't know if this is what you're talking about necessarily, but in the late 1970's as a young guy in my mid 20's I drove my grandpa's Oldsmobile alone from his home in Norfolk, Nebraska down to my family's home in Tucson, Az. He'd then fly down to Tucson as he was too old to drive by himself.
I will never forget the first night of driving. I was heading straight south from Norfolk, and probably near Stromsburg on Hwy 81 when a wild tornadic storm came into view due south of me. It was probably south of I-80 near Geneva, Neb. at the time I'd guess. Back in those days, cars only had AM-FM radios. Well the lightning was so bad within this storm the radio was 100% static. I'd never experienced this before. As I kept driving south, suddenly within the storm I saw a large tornado completely "wrapped" in lightning...from top to bottom. If you can envision a large tree-trunk entirely wrapped in hundreds of light bulbs, this is exactly how this tornado was. Every square inch of the funnel was lit up in vivid orange electricity. This funnel would light up like this every few seconds....for a good 10 min. Truly, it was beautiful. I have never come close to seeing this again.
Tim Marshall once said that his mother told him as a kid that to watch for a tornado, look for the "circular lightning" within the storm. What I saw must have been what she meant.

 

[Kirk Chestnut]

Anedotal but my High School Physical Sciences teacher told us a similar story where he observed an area of concentrated lightning one evening while driving. It turned out a tornado was reported in the vicinity. That story stuck with me all these years.

As a storm spotter in Lincoln, it was always very unnerving how the noise floor on the 2m band would rise on very robust storms and drop to silence after a lightning strike. There would be times the noise was so pronounced that I could not hear the repeater and expected to be holding the smoldering remains of my microphone. I never did have a chance to correlate a funnel siting with noise on 2m.

 

[Todd Rector]

I am planning on taking my daughter on that same little pilgrimage later this year. She is a Wizard of Oz fan, but does not know the Irving story. I am going to have her read the relevant chapters from Storm Kings on the trip there.

 

[TrumanBoyer]

1000-2000 feet AGL is a favored area for the initiation point of the CG discharge (bi-directional leader). The upward ground leader initiates close to the ground in response to final stages of the stepper leader descending.

It's a good thought, but cloud droplets/crystals are what *become charged* within a cloud. In that sense the droplets/crystals are non-conductive objects that become charged, similar to a balloon that gets charged by rubbing it on wool. Lightning doesn't follow neutral cloud material (for example, we don't see bolts always following the leading edge a shelf cloud down to the ground), but charged regions of clouds aloft can allow the lightning to continue to propagate.

Charge buildup (negative charge) in the lower to mid-levels of the cloud induces a positive charge in the ground below.
Normally in a CG stroke, the downward moving negative charge induces a more concentrated positive charge to start moving inward and upward toward it. The reason the upward moving leader is shorter, and happens in the last few milliseconds, is because the positive-charged particles are more massive (usually thousands of times more) and thus require more energy and time to accelerate them.

A debris cloud could move positive charge several thousand feet upward, and become, in effect, a ground leader
in the much same way that a tall building, or tree, can become a ground leader.

Liquid droplets of pure water are fairly good insulators, (or poor conductors), but ionized water is an excellent conductor.
The same is true of air molecules, btw.
We are certainly discussing ionized water here, since droplets/crystals ARE what become charged within a cloud.

It is widely accepted that droplet, or crystal, splitting is what is responsible for charge separation within a cloud.
It is reasonable to assume this happens most within the more turbulent parts of the cloud. (more collisions, etc)

I am another one pleased at the amount of attention this thread is getting.

I am so curious and have spent a lot of time studying all aspects of thunderstorms, and no one spends more time
observing thunderstorms than we do. I have always been very pleased to be part of this "community".

I think many of us, me included, are usually exhausted shortly after sunset. I often night chase, and I always hate it
when I have to hit the sack before the light show is over. I have often wondered how many phenoms we miss because
just because of DAY 2 considerations.

I have more on this subject if anyone cares to hear. If am beating it to death, just tell me to shut up. LOL.

-T