Image: Not a very good illustration*
Therefore, researchers (mostly funded by electric companies) would like to devise a method to trigger lighting and guide the discharge to harmless spots. In the March 1999 issue of Journal of Optical Technology, researcher Jens Schwarz at the University of New Mexico (Albuquerque) explained the process: "The idea is that the laser light creates a conducting path between the cloud and the ground, triggering the lightning discharge."
Groups in Japan, Russia, and the U.S. are using different laser wavelengths and powers to create conductive paths between the ground and thunderclouds. Most of the work is still laboratory based, but one group in Japan reported successfully triggering two lightning strikes using their laser system.2 Shigeaki Uchida and colleagues at Osaka University in Japan, appear to have initiated the lightning strikes during field experiments on the shore of the Sea of Japan.
During thunderstorms, a large electrical field between the ground and clouds develops. High conducting points, such as the tops of towers built specifically to draw lightning, are usually surrounded by a corona discharge. When this discharge is quenched (such as when there is an abrupt change in the field under the clouds), an electrical leader starts from the top of the tower. If this occurs when the clouds are beginning to discharge, this leader initiates a lightning strike. By using laser beams to create plasma channels at the tops of the towers, Ushida's group has, to the best of their knowledge, reported the first laser-plasma-triggered lightning.
The group of researchers in New Mexico that Schwarz works with use 248-nm UV lasers, rather than the combination of IR and UV beams. This method is expected to have the benefit of allowing much lower powers to be used -- tenths of a joule rather than hundreds or thousands of joules per pulse. Even when using these low energies, the very short pulses (about 500 fs) cause very high peak powers; at the moment, peak powers of 20 GW are being used for lab tests.
In the atmosphere, the ionizing power is leveraged. Schwarz said, "The UV beam creates a path of electrons that can move in the ambient electric field (the one between cloud and ground) and multiply via avalanche ionization."
In addition to studying the properties of air under the influence of intense laser beams and plasmas, the New Mexico group is primarily focused on two main areas: improving the laser system (by increasing the reliability and power), and making a more portable system, which will be useful for field experiments.
The material above is conveying a story about non classified research, but one can only wonder about what must be happening in the world of black-ops.
What could a well financed covert operation develop if given decades to advance such technology? What would happen if such technology were placed on board stealth aircraft, or stealth UAVs, and then flown into inclement weather? Could weather be covertly modified? Could a laser triggered particle beam weapon be developed?
Who, or what has the motive, the means, and the opportunity to develop technology capable of triggering lightning?
According to the article above electric companies do.
Would the U.S. Defense, and intelligence community possess the motive, means, and opportunity to covertly develop technology to trigger lightning?
I posted the following material several months ago. This seems to suggest that a motive exist.
Owning the Weather in 2025
A Research Paper
Air Force 2025
Col Tamzy J. House
Lt Col James B. Near, Jr.
LTC William B. Sheilds (USA)
Maj Ronald J. Celentano
Maj David M Husband
Maj Ann E. Mercer
Maj James E. Pugh
Page 15: "If this UAV technology were combined with stealth and carbon dust technologies, the result could be a UAV aircraft invisible to radar while en route to the targeted area, which could spontaneously create carbon dust in any location".
Page 19: " One area of storm research that would significantly benefit military operations is lighning modification. Most research efforts that would significantly benefit military operations is in lightning modification. Most research efforts are being conducted to develop techniques to lessen the occurrence or hazards associated with lightning. This is important research for military operations and resource protection, but some offensive military benefit could be obtained by doing research on increasing the potential and intensity of lightning. Concepts to explore include increasing the basic efficiency of the thunderstorm, stimulating the triggering mechanism that initiates the bolt, and triggering lightning such as that which struck Apollo 12 in 1968. Possible mechanisms to investigate would be ways to modify the electropotential characteristics over certain targets to induce lightning strikes on the desired targets as the storm passes over their location".
Here's an Air Force PDF version of the document.
*Image used above is not mine. It was used without permission from the SPIE website.