Cloud seeding is a form of weather modification, a way of changing the amount or type of precipitation that falls from clouds.
A University of Wyoming researcher has demonstrated the direct observation of cloud seeding, from the growth of the ice crystals through the processes that occurs in the clouds, to the eventual fallout of the ice crystals that become snow and how the impacts can be quantified for the first time.
“No one has ever had a full comprehensive set of observations of what really happens after you seed the cloud,” Jeff French, an assistant professor in UW’s Department of Atmospheric Science, said. “There have only been hypotheses, but there has never been a set of observations from one campaign that shows all the steps that occur in cloud seeding.”
The research, dubbed SNOWIE (Seeded and Natural Orographic Wintertime Clouds -the Idaho Experiment), took place Jan. 7 to March 17, 2017, within and near the Payette Basin, located approximately 50 miles north of Boise, Idaho. The research was in concert with Boise-based Idaho Power Co., which provides a good share of its electrical power through hydroelectric dams.
“In the case of this project, the silver iodide was released by a second aircraft funded through Idaho Power Co., while the UW King Air took measurements to understand the impact of the silver iodide,” French said.
French is the lead author of a paper, titled “Precipitation Formation from Orographic Cloud Seeding,” which appeared in the Jan. 22 issue of the Proceedings of the National Academy of Sciences, one of the world’s most prestigious multidisciplinary scientific journals.
Other contributors to the paper were from the University of Colorado-Boulder, University of Illinois at Urbana-Champaign, the National Center for Atmospheric Research (NCAR) and Idaho Power Co.
“SNOWIE was a great collaborative effort and it shows the value of private, public and academic partnerships,” NCAR scientist Sarah Tessendorf, a co-author of the paper, said.
The research project was mainly funded by the National Science Foundation (NSF). State of the art technologies, such as, ground-based radar and radar on UW’s King Air research aircraft, aided in the research.
“This research shows that modern tools can be applied to long-standing scientific problems,” Nick Anderson, program director of the National Science Foundation’s (NSF) Division of Atmospheric and Geosciences, said.
Numerical modeling of precipitation measurements were conducted using the supercomputer, nicknamed Cheyenne, at the NCAR-Wyoming Supercomputing Center. Numerical models allow researchers to study future storm events, where measurements have yet to be obtained in the field.
