BOISE — Officials say a planned study of storms passing through the Payette range this winter should provide first-of-its-kind data on the physics of cloud seeding, thereby enabling weather-modification programs to better quantify their results.
The $2.1 million research project, funded by the National Science Foundation, will involve Idaho Power Co., University of Colorado-Boulder, University of Wyoming, University of Illinois and the National Center for Atmospheric Research.
“We are interested in understanding the natural dynamic and micro-physical processes by which precipitation forms and evolves,” said Katja Friedrich, a professor with University of Colorado’s Department of Atmospheric and Oceanic Sciences, adding the data could also help with selecting generator sites and the best types of clouds to seed. The process involves releasing silver iodide into clouds to form more ice nuclei and bolster mountain snowpack.
Jeff French, an assistant professor of atmospheric sciences at University of Wyoming, said this will represent the second major study on cloud seeding since improvements in instruments recently rekindled interest in the subject, after seeding research halted in the early 1980s.
University of Wyoming finished the other recent study in the winter of 2014, but French emphasized seeding infrastructure in the Payette, where Idaho Power has long run a seeding program, is far superior to the area analyzed in Wyoming.
French said the Wyoming project utilized only ground-based seeding generators and relied upon modeling of cloud response. For the Payette project, his university will provide a King Air plane to fly into clouds as they’re seeded by another aircraft and ground-based generators, recording results for comparison with unseeded clouds.
“We need some validation of the production of ice due to cloud seeding,” French said. “That’s what we’ll be able to get with measurements of the King Air — how many ice crystals are being produced — then we can verify our model is capturing this correctly.”
French said the additional research is especially timely for Wyoming, which recently completed a six-year seeding pilot project and is commencing with a state-sponsored program.
Idaho Power initially experimented with cloud seeding in 1995, and has administered a program consistently since 2003 to benefit its hydro-power operations.
Jon Bowling, the electric company’s engineering lead, explained the program will have a roughly $3.6 million budget this winter, with partners contributing more than $1 million. Pledges for this winter from water users include $600,000 from the Idaho Water Resource Board, $125,000 from the Boise water district, $125,000 from the Wood River water district and $200,000 from the Upper Snake River water district. The company also plans to meet with the water board about additional funding to further develop tools to verify benefits of cloud seeding, down to the acre-foot.
Shaun Parkinson, Idaho Power’s senior water management engineer, said the program has grown its infrastructure by 40 percent during the past two years but will add only three new generators to the system for this winter. In the future, Idaho Power will prioritize adding a second aircraft in the Upper Snake, he said.
Last winter, Idaho Power estimates its seeding increased the snowpack in the Payette by 11.5 percent, in the Boise by 9.4 percent, in the Wood River by 5.4 percent, in the Northern Snake by 4 percent and in the Eastern Snake by 5.4 percent. Once the program is fully developed, Parkinson projects it will cost $3.6 million per year to run and will result in an extra million acre-feet of water, at a cost of $3.60 per acre-foot, compared with the current rental pool rate of $17 per acre-foot.