Scientists Just Created Rain and Snow on Demand in Idaho With Cloud Seeding

Wednesday, 24 January 2018 - 1:46PM
Science News
Wednesday, 24 January 2018 - 1:46PM
Scientists Just Created Rain and Snow on Demand in Idaho With Cloud Seeding
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Image credit: Unsplash

The ability to modify the weather has long belonged in the realm of science fiction, but now a team of scientists in Idaho think they've figured out how to make it happen outside a lab.



Cloud seeding, the process of causing tiny particles in clouds to break into rain or snow, is a decades-old process, but it has long been confined to controlled experiments in pristine conditions. - has been studied for decades, but it is only now that researchers say they have proven how it works outside a laboratory. Kurt Vonnegut based his fictitious ice-nine on this original discovery, which may be responsible for how fantastical this all seems.



By identifying the chain of events from cloud seeding to actual precipitation on the ground, scientists can now figure out what hasn't been working since the technique was first discovered in the '40s. Though we discovered back then that silver iodide causes supercool clouds of water vapor to freeze into snow in a lab, the equipment of the day wasn't able to measure droplet sizes in real time, and erratic weather patterns made controlled experiments near impossible.

 

"Once you seed, you're contaminating the cloud. You can't repeat the experiment because you'll never have the same atmospheric conditions again," Katja Friedrich, an atmospheric scientist at the University of Colorado in Boulder, told Science Magazine.



Now with funding from the National Science Foundation and Idaho Power, Freidrich and her team are ready to try a new approach. Traveling to the mountains of southwestern Idaho, they waited for supercooled clouds to appear, then flew an aircraft over the clouds that dropped silver iodide onto them.



"The radar can only see [water] particles that are big enough, and these clouds had tiny droplets not detectable by radar," said Friedrich. "Suddenly, we saw lines appear. It was really astonishing." The lines matched the flight path of the plane, and within them they saw the cloud's water particles grow, hit the silver iodide, and freeze. A couple of hours later, the snowflakes became heavy enough to hit the ground.



"The intent of glaciogenic seeding of orographic clouds is to introduce aerosol into a cloud to alter the natural development of cloud particles and enhance wintertime precipitation in a targeted region," reads the abstract of this study on the breakthrough. "Here, the full chain of events from ice initiation through crystal growth and fallout of snow has been documented. These observations are critical to our understanding of how cloud seeding works and will help direct future research efforts into the effectiveness of cloud seeding."



Other recent meteorological breakthroughs include the creation of diamond rain to study Neptune's strange weather, and the discovery of a new planet that snows sunscreen.

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