Lasers could soon be used to direct dangerous lightning away from sensitive areas, like airports.
A few weeks from now, scientists will be gathering in Geneva, Switzerland, at the second Conference on Laser, Weather and Climate, to discuss how they can use lasers to generate clouds, produce rain and control lightning strikes.
Controlling the weather has long been a dream for humankind, whether its to give us rain for parched crops or to prevent disastrous hurricanes and tornadoes. Attempts at weather control so far have mostly involved firing or dumping particles into the air, either to get clouds to form or to dissipate storm clouds before they can produce damaging hail, winds or even tornadoes. These attempts have had mixed success, and there is a growing concern about dumping these particles into the air, as they may have unknown effects on the environment. Lately, though, scientists have been turning to lasers, as a cleaner, easier and more high-tech option.
There has been plenty of research in recent years about using lasers to cause or direct lightning strikes. Lightning always takes the path of least resistance, but it has to create this path itself (by forming a trail of ionized air), and it doesn't always create that path to areas that are in our best interests. However, if you fire a powerful laser into a cloud, it can create that same kind of ionized trail, giving the charge in the cloud an artificial path to flow along, thus discharging the lightning safely. Researchers have found that you can even accomplish this while the lightning is in mid-strike.
The research into weather control through lasers doesn't end there, though.
Scientists have also found that extremely short bursts of laser light can cause water to condense out of the air, even in situations where conditions where clouds can't form on their own. The effect is so strong that it might even be able to produce rain if more continuous pulses are used.
Other experiments (so far conducted in cloud chambers) have shown that lasers can cause rapid formation of ice crystals in conditions that match where high cirrus clouds form in the atmosphere. Given that cirrus clouds are very effective at reflecting sunlight back into space, there is great potential to use this method to reduce the strength of thunderstorms and hurricanes, and possibly to help alleviate some of the effects of global warming while we ween ourselves off fossil fuels.
