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March 5, 2020

Kinda Flakey

Cloud seeding has become an increasingly popular practice in the western United States, where states grapple with growing demands for water. Measuring how much precipitation cloud seeding produces has been a longstanding challenge. Researchers have developed a way to use radar and other tools to more accurately measure the volume of snow produced through cloud seeding. And the answer is...

Credit: National Science Foundation/Karson Productions

Uploading to the cloud.

I'm Bob Karson with the Discovery Files, from the National Science Foundation.

Arid conditions and sparse precip put a strain on available water supplies in the western U.S. To help nature along, cloud-seeding has been trending as a way of upping the amount of water that falls as snow. But until now it was a challenge to measure just how much new snow gets generated. Findings of a multi-institution study help clear up this cloudy question.

(Sound effect: mid-sized plane takeoff) Team members took to the skies over western Idaho in a specially equipped plane that could fire flares of silver iodide into existing clouds. Injecting this plume of microscopic particles encourages water droplets to form into ice crystals that generate snow.

Using hi-tech meteorological gizmos including Micro rain Doppler Radar strapped to a truck on a mountain, the researchers were able to track each plume, watch the snow form, and follow it to the ground. In three trips over a month, the group generated and measured enough water in the form of snow to fill some 282 Olympic-sized swimming pools (Sound effect: diving board/splash) -- from clouds that otherwise wouldn't have produced a single flake. In total it snowed for 67 minutes, dusting an area of 900 square miles.

So, cloud seeding works. How well is snow longer a mystery.

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