In California, this is often done during the winter when temperatures inside the clouds are far below freezing. In , Jerome Kasparian at the University of Geneva in Switzerland came up with a new method to summon clouds — this time using lasers.
Some however remain sceptical, arguing that what has been demonstrated in the lab cannot necessarily be repeated in the variable and unpredictable conditions of our atmosphere. Tilley says scepticism around cloud seeding is understandable because relatively little funding goes into research that could convince doubters it works.
Today that funding often comes from authorities wishing to guarantee water supplies although the US military was once reportedly interested in using cloud seeding to extend the Monsoon season during the Vietnam War as part of its combat strategy. Several airports in the western US including Boise Airport, in Idaho, use cloud seeding as part of efforts to clear thick fog that would otherwise cause flight delays.
Another laser-based weather control system could help keep airports open during severe thunderstorms. In , Kasparian and his colleagues fired laser pulses into thunderclouds in an attempt to suck out lightning in a controlled manner. Their efforts were unsuccessful — perhaps because the laser beams needed to be more powerful to trigger lightning, says Kasparian.
Yet a similar experiment by another research team in succeeded, at least in the lab. They used a laser to divert artificial lightning so that it travelled down a controlled path.
What about our ability to prevent dangerous weather formations such as tornadoes? Weather Bureau] came up to me, and said, 'You know, about 10 years ago I was calibrating thermometers in a cold chamber using dry ice, and I wasn't smart enough to realize I had something important. As research moved forward, however, Schaefer and Vonnegut saw weather modification become less about modifying weather and more about enhancing it.
Even so, because of its science-fiction-like possibilities controlling the weather is a superpower , after all , weather modification has always led to aspirational inventions and promises of clear skies. Boe cited hail cannons, which claim to stop hailstorms by generating shockwaves. They've been used often throughout Europe since the early 20th century, but have no evidence of actually suppressing hail. That's not to say the decades since Schaefer and Vonnegut's dry-ice experiments have been for naught.
Though complete weather modification may never be possible, Boe explained the technology involved has leapt forward. In , for example, he navigated planes through clouds without GPS and used carbon-dioxide pistols to catch cloud droplets on glass slides. He had to later bring those slides to a lab, where he could examine them under microscopes.
Today, he uses optical array probes, diodes, and lasers that show in real time the size, shape, and number of particles in a cloud while he flies. And before taking off, he can simulate the cloud seeding to select the right clouds.
It's not only more efficient, but more accurate as well. Radar on the aircraft and on the ground provided data about the broader cloud structure.
The results will aid in future cloud seeding in Idaho. They also will help scientists understand the natural traits of clouds and what goes on within them.
Meanwhile, human activities have begun changing the weather — and in some less-than-subtle ways. Kevin Petty is a meteorologist and the chief scientific officer for Vaisala, in Louisville, Colo.
This company provides weather-related observations and software to governments and other groups to help with decision-making. Weather and climate are different beasts, but they are related, he notes. One of the best ways that Petty has seen this summed up is: Climate is what you expect; weather is what you get. Those gases act like a big blanket covering Earth. They help to keep heat in.
Without those gases, Earth would be a giant ice ball. The planet is now holding in more heat than it has for thousands of years. And those effects are wide-ranging. Average temperatures on the planet have been increasing, notes David Titley. He headed up a task force on climate change when he was a rear admiral in the U. What was considered a hot day in the s tends to be several degrees cooler than it is now.
No surprise, Earth has been setting regular records for average temperature, with , and being the hottest on record. Warmer air also causes more water to evaporate from the soil. Scientists are still looking into how climate change might affect other types of extreme weather, such as hurricanes and tornadoes.
The heavy rains and particularly strong winds in the recent spate of hurricanes that struck the United States in — Harvey, Irma and Maria — were probably due in part to climate change.
These changes to weather patterns ripple across the planet. They cause problems from the minor to the extreme. Worse effects will be — and have been — felt elsewhere in the world.
Syria is a nation in the Middle East where a civil war has been raging for years. That conflict was sparked in part by a bad drought. He means energy sources such as hydroelectric, solar and wind power, and possibly nuclear power. But scientists also have proposed two methods of climate intervention, or geoengineering.
One idea is to somehow suck excess carbon dioxide CO 2 out of the atmosphere. That will not be easy. There are just or so molecules of CO 2 for every million molecules of air. Humans have gotten really good at predicting the weather, but we've had a hard time figuring out how to control it.
Now with the threat of rising global temperatures and severe droughts, scientists are racing to develop technologies that will actually change the weather.
Scientists are literally "making it rain. It has already been tested around the globe. The goal is to increase precipitation in places with water shortages. Cloud-seeding is a form of geoengineering— or manipulating of weather systems to reduce the negative effects of climate change.
Here's how it works. Silver iodide gets sprinkled into clouds by airplanes or blasted up into clouds on rockets.
Another possible technique that China is exploring is using winds to naturally transport the silver iodide into the clouds. Silver iodide has a very similar structure to ice, so the ice crystals in the cloud will bond to it, making the cloud increasingly heavy until it releases its moisture as rain or snow. And so far, preliminary tests look promising. The European company called Oliver's Travels offers "cloud-bursting" services to prevent rain on your wedding day.
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