Lightning Research

Mike writes: "There was a great topic covered on tonight's episode of ABC's NightLine. They discussed lightning and how a group of researchers at the University of Florida have been able to develop rockets that "pull down" lightning and allow them to gather data to help find out more about it. They can capture lightning bolts with relative ease and film the bolts with high-speed cameras, revealing that what appeared as a single flash to the naked eye was often times three or four bolts in extremely rapid succession. While the article doesn't go into the detail that was covered on TV, you do get a video clip and nice overview. And photos and additional details are available at the University of Florida's Lightning Research Lab web site."

Comments

Re:Recycled story on ABC's part

[yadung]

I remember a story a long time ago(don't know which channel) where scientists set up a mock neighborhood, and sent up rockets to bring the lightning down into the neighborhoods wires to learn more about what happens when struck and how to prevent it. I think it was UF...

Power source?

[HongPong]

I have always wondered about the possibility of harnessing lightning's energy as a source of electricity. While I'm not an electrical expert in ANY sense, I wonder if it would be possible to develop a gigantic antenna, grounded, which would attract lightning, and milliseconds after the initial strike, a very powerful relay would flip the lightning's course from an open path to the ground into some ridiculously strong diodes and battery configuration. Obviously this wouldn't be feasible unless, at the least, diodes and relays capable of handling millions of volts and lots of amps (does static electricity have amperes?) are developed.

I have no idea if this is at all possible, or even remotely logical, but I'd like to hear what someone who's an expert thinks.

Re:Power source?

[Skapare]

Lightning is just an artifact of existing energy fields. You could reap that energy even before there are lightning strikes (and on a large enough scale, perhaps reduce the lightning or even eliminate it). The "antenna" would basically be a bunch of very tall lightning rods. Lightning rods don't serve to attract lightning, but rather, serve to dissipate static charges that are exaggerated during a thunderstorm. That dissipation does result in a flow (amperes is a measure of electrical current, coulombs is the measure of electrical charge, and farads is the measure of the capacity to store an electrical charge). The trick to accomplishing what your suggest is to avoid the air insulation breakdown that results in a sudden flow (the lightning stroke). The problem is that unless the rods are very tall, the flow is inhibited by extreme air resistance until the breakdown occurs (which is very rapid when it happens, with rarely more than a few seconds notice, if that). I'd guess that the height needed to efficiently exploit air charges would be 1 to 5 kilometers. Once you get that high, you will get currents even without the thunderstorms.

Benjamin Franklin's key experiment supposedly didn't actually get a stroke of lightning, but got a charge fed to it that perhaps was coming close to breakdown voltage. But that charge could have developed even without the storm, although at a lower level. A charge develops in the atmosphere every day due to photon energy striking the atmosphere within a magnetic field. The air serves as an insulator, and you have a giant capacitor. Lifting in the air, which occurs more extreme during a thunderstorm, changes the dynamics of that capacitor, reducing its farad measure, and given a constant of coulombs, raises the voltage of the charge. Raise it enough and the air insulation breaks down. But the charge is there all the time. The question in science is just how much of that charge comes from various sources. Apparently the charge from sunlight isn't enough to bring about the level of lightning we actually see.

Another source of energy you can extract from a thunderstorm is lateral charge shifts from horizontal storm movement. The storm carries a concentrated charge, and to balance that out, the earth exhibits a counter charge gathered near the surface to be as close as possible to the storm. That charge moves along with the storm. This charge movement is often the source of damaging levels of electrical current in some extended wiring like rural telephone lines. I've watched the charges dance off lines miles from thunderstorms. There might be a way, given wide open spaces, to exploit that.

The lateral charge effect can also cause some interesting lighting. I once saw a lightning stroke emerge from the half way up the back side of a tall thundercloud into the clear air in its wake, and jump some 10 to 12 km back, then bend down to the ground. The earth charge hadn't followed fast enough and apparently got built up way back there somewhere.

I had another interesting experience once when taking advantage of a clear weather break in the midst of a stormy week, to do some site surveying for radio coverage when I was doing storm spotting years ago. I first noticed some strange whistling sounds in my car AM radio. It started at a high pitch and dropped down to nothing in about 1 to 4 seconds, repeating after after another 1-4 seconds. When they started coming faster I started feeling some "static bites" in my handheld 2m ham radio (KA9WGN) which was connected to an antenna on the car roof. I pulled off the antenna connector from the radio and put the tip of the BNC connector pin (which went to the actual antenna rod itself, which being a 5/8-wave style, had no loading coil) up to the keys in the car ignition switch. At about 1 cm distance, a spark jumped across. At about 3 mm distance, it sustained a spark repeating about every 2/3 second continuously. I opened the car window and looked around and up, and saw a small cloud forming directly above. It was very small, not any larger than a "partly cloudy day" kind of cloud. But I decided to drive away anyway. About 10 minutes later I was 3 miles south east and looked back northwest and saw that my little cloud had become a billowing thunderhead. 5 minutes later there were cloud to ground strokes.

Also a problem for lunar tourists

[kingdon]

Reminds me of when the Apollo 12 mission to the moon was struck by lightning shortly after liftoff. Here's an article including pictures. Pretty amazing that the spacecraft's electronics survived this and they still managed to go to the moon after rebooting everything. Here's an item from the RISKS digest about one of the reasons why that worked.

Lightning Research/Camp Blanding

[emolitor]

The Lightning Research UF does is pretty cool. I drove by (what is and what became) their research facility going to and through Gainseville for years.

The research is done at a former military base (camp blanding IIRC). The rockets are shot from the old repelling tower (gives a slight boost as the tower is right about the same height as the pine trees that surround the facility) You can park on the highway and see where they launch the rockets from. Just dont walk around there with any big metal poles during a storm.

The rockets occasionally trigger natural lightning which is much stronger than the "triggered" lightning caused by the rockets. Its pretty cool to watch but in general its so bright and so fast you really dont see much other than the light trail burned on your retina.

Neat stuff.

Nightline was very informative.

[Schwarzchild]

I realize that a lot of people are posting that it is old news but I haven't seen this before and I haven't seen anybody talk about the truly bizarre lightning phenomena that they discussed on Nightline, that is, the wide weakly powered lightning which occurs above the clouds (called Sprites, I believe), the high powered lightning that shoots out from clouds and goes up into the upper atmosphere and lightning that spreads like a halo (called Elves)

They also posited that the Sprites may be weak enough that they could have caused life to form. Other theorists had thought that lightning might have caused life but the power from regular lightning is too strong; however, this new form of lightning is weak enough that it might do the trick according to the researchers.

The blue jets that emanate from clouds and rise up into the upper atmosphere are supposed to be extremely powerful and are considered a danger to stratospheric aircraft, rockets and the space shuttle.

All in all it seems to be very strange phenomena. Add ball lightning to the mystery.

A Scientic American link on Sprites and Elves.