A "dressed laser" system could one day be used to control the weather. Researchers from the University of Central Florida (UCF) believe they may have discovered a way to induce changes in the weather using two lasers.
Storms, lightning strikes and condensation are each accompanied by large quantities of the particles, charged with static electricity. By controlling these particles, it may be possible to control the formation of precipitation and encourage lightning.
According to Matthew Mills, a graduate student at UCF, beams from extremely powerful lasers collapse on themselves.
"The collapse becomes so intense that electrons in the air's oxygen and nitrogen are ripped off creating plasma - basically a soup of electrons," Mills told reporters.
For a short while, the ionized gas is caught between collapse and expansion, creating a "light string." This process is known as filamentation. Soon, air forces the beam to disperse. Before that occurs, the give-and-take of the laser dispersal can create electrical disturbances in clouds. The trouble was that lasers powerful enough to change the weather dissipated within ten inches of the laser, keeping the beams far from clouds.
Mills and graduate student Ali Miri found that if they "dressed" this filament using another, lower-powered, laser, it can extend the length of the filament. This outer shell not only greatly extended the range of the filament, it also acted as a power source for the inner core. However, so far, they have only achieved a dressed filament seven feet long.
"Since we have control over the length of a filament with our method, one could seed the conditions needed for a rainstorm from afar. Ultimately, you could artificially control the rain and lightning over a large expanse with such ideas," Matthew Mills predicted.
The study with its potential for future weather control, was funded by a $7.5 million grant from the Department of Defense.
Dressed filaments could also be used in spectrometers to identify the physical makeup of distant objects and to guide microwave transmissions. Such transfers of the electromagnetic radiation could, one day, allow the energy to travel hundreds of feet.
"This work could ultimately lead to ultra-long optically induced filaments or plasma channels that are otherwise impossible to establish under normal conditions," Demetrios Christodoulides, a UCF professor guiding the project, said.
By controlling precipitation, it may one day be possible to bring rain to arid regions, and relieve droughts that would otherwise wipe out crops. During forest fires, a human-designed deluge could dampen the blaze, and reduce smoke released to the atmosphere.
Study of how lasers could be used to stimulate precipitation was detailed in the journal Nature.
