The Farmers Gazette | Page 13

New Tech Uses Drones For Cloud Seeding D esigned to potentially help droughtplagued regions, a new technology uses unmanned aerial vehicles — also known as drones — to put more water into the clouds. When you think of drones, you probably think of military ones but if the Desert Research Institute in Reno, NV has its way, drones may soon have more to do with water than the military. The Institute is working on a drone to promote precipitation. Piloted planes have already been used for this purpose, which is known as "cloud seeding." For over 60 years piloted planes as well as ground bases have been used to spray silver iodide particles into passing clouds to squeeze more precipitation from the atmosphere, a practice which has typically resulted in about 10% more rain. The Institute’s Meteorologist Jeff Tilley explained that this is the first time drones have been used for the same process. Compared to the plane mission, the process of the seeding itself will not drastically change, Tilley explained. Some changes will have to be made to the size of the seed flares due to the compact size of the drone versus a manned aircraft. Planes can produce an additional one billion gallons of water for every 25 to 45 hours in flight, but manned aircraft need to stay above the clouds for safety reasons, according to aviation regulations. Drones are the perfect size and shape to support this process. "The smaller size of the drones, and the fact they are not manned, provides potential opportunities for drones to fly below the cloud base and seed there as well as at cloud top," Tilley said, per the report. “Drones can fly through the clouds and can stay aloft longer, producing even more precipitation for communities devastated by drought.” This new technology could reduce cloud-seeding costs by half, since it does not include steep piloting and fuel costs, like planes do. Cloud seeding has become increasingly widespread. Once viewed by some as a fringe science, cloud seeding has entered the mainstream as a tool to pad the state’s crucial mountain snowpack. New technology to manage the practice, and research that points to reliable results, have cemented cloud seeding as a dependable and affordable water-supply practice. A major test of cloud seeding, conducted last year, revealed mixed results about its effectiveness. The experiment was one of the longest-running and most rigorous tests yet of ‘cloud seeding’. An independent team of scientists now says that it worked — sort of according to the magazine, Nature. "Seeding the clouds squeezed 5–15% more precipitation out of them,” says Roy Rasmussen, a meteorologist at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, who led the evaluation team. But that statistic holds only if scientists eliminate parts of the test that went wrong, such as when the silver iodide spray did not completely cover the mountain range that the researchers were trying to seed the report said. In 70s and early 80s rockets generating highheat at explosion were used in the Eastern European Countries to transform potential hail clouds into rain and it worked well saving many agricultural fields from a hail disaster. However, there was a danger that rockets may fall on the ground to explode. FARMERS GAZETTE November 2015 11