Skipping over to the western hemisphere and Missile thingy Cheney's home state:23 January 2005 - The Billings Gazette
Snow in the making: Cloud seeding boosts snowpack for water supplywww.billingsgazette.com/index.php?id=1&display=rednews/2005/01/23/build/wyoming/FARSON, Wyoming -- Each winter, Bonnie Moody watches the weather like a hawk from the Eden Valley Irrigation District's small shop here.
Moody, the district's manager and water master, is looking for winter days with just the right temperature, just the right wind direction and speed, and just the right kind of clouds in the sky. When conditions are right, Moody makes snow.
This year marks the third winter Moody has been working on a cloud-seeding program that aims to increase water in the district's Big Sandy Reservoir by boosting the snowpack in the nearby Wind River Mountains. The Wind Rivers are the main water source for the district's irrigation system.
"There is kind of a real art to this," Moody said during a recent demonstration of one of the district's cloud-seeding units.
Although Moody has been at it for just three years, the Eden Valley cloud-seeding effort has been under way since the 1960s, a result of research conducted by the University of Wyoming. The effort involves the use of burners to release silver iodide into clouds to enhance the potential for snowfall.
The irrigation district has done no research to determine if the project has boosted snowpack, but anecdotal information and data collected from snow course reading sites indicate there may be a 7 to 10 percent increase, Moody said.
Coming off years of drought, Wyoming water officials are proposing a dramatic expansion of cloud seeding. A proposed $8.825 million, state-funded weather modification program in the Medicine Bow/Snowy, Sierra Madre and Wind River ranges is intended to provide additional scientific data to help determine whether such seeding would increase snowpack.
The proposal would further test the theory that releasing silver iodide into the atmosphere at locations and times when there is moisture present could increase snowfall.
The study is supported by the Wyoming Water Development Commission, which has submitted a budget request for the project that will be considered by this year's Legislature.
Although the first weather modification permit in Wyoming was issued in 1951, no state-funded cloud-seeding program has been in operation. The Eden Valley project is funded by the irrigation district, Moody said, at an annual cost of $4,500, not counting labor.
Other states are also involved in weather modification projects. A program in Utah began in 1989 and by 2003 involved 130 ground-based generators, at an annual cost of $336,000. Ongoing modification programs also are under way in California's Sierra Nevadas.
In the 1960s and 1970s, professor John Marwitz and others from the UW Atmospheric Science Department conducted weather modification studies in the Eden-Farson Valley and on Elk Mountain in Carbon County. They did not seed clouds to boost snowpack. They were studying details of weather modification such as determining how fast ice crystals would grow.
From the data they collected, Marwitz said, "It always looked very promising" in the Farson area, with the potential for about a 10 percent increase in snowpack.
Although the Elk Mountain experiments weren't as promising, Marwitz said that area also had potential.
"I think there was probably a real possibility that we could have increased the snowpack there," he said.
The difference between the two areas relates to geography - the size and shape of the mountains in each location.
Marwitz said the key question related to the effectiveness of future weather modification projects in Wyoming is, "Will (the air) go up and over the mountain, or will it go around the mountain?"
In the early studies at Elk Mountain, the UW researchers found that the mountain was "too short" and that there was not adequate time for ice crystals to form once cloud-seeding materials were released. So instead of additional moisture falling on the mountain, what moisture accumulated as a result of the seeding mostly evaporated, and a limited amount fell on the east face of the mountain.
In the Eden-Farson area, however, the mountains are broader, so the modification studies there were more effective, Marwitz said. That led to the cloud-seeding project.
A key to effectiveness is location of burners and how air currents flow in specific areas.
"Every mountain is a little different. Every mountain has its unique characteristics. You have to do these kinds of tests somehow prior to actually seeding any mountain," Marwitz said.
No additional work was done in the Elk Mountain area, and UW halted all of its weather modification research in 1987, Marwitz said. He retired in 1999 and said he had intended to bid on the current feasibility study being done by Weather Modification Inc., of Fargo, N.D., but he missed a bid deadline.
The Eden Valley project targets the south end of the Wind Rivers when wind, temperature and cloud conditions are "right." The state's proposed project would expand the seeding operation to basically encircle the entire Wind River Range, said Bruce Boe, meteorologist for Weather Modification Inc.
The Wind River and Sierra Madre/Snowy Range weather modification program likely would involve the location of ground generators about 30 miles apart placed all around each of the ranges.
By comparison, Eden Valley's cloud-seeding effort is tiny. Three burners located along Wyoming Highway 191 are operated manually, but the district also has two propane-fire cloud seeders on Muddy Ridge that can be started by remote operators in Provo, Utah.
The district seeds clouds beginning around Nov. 15 if conditions are right and runs the program through the middle of April.
Moody said the cost of the silver iodide - about $2,500 per container - is the most expensive part of the program.
She said the district has noticed slight increases in precipitation since the program began, though there have never been any scientific studies to determine the precise effect of the effort.
"But the problem is, when we're in drought years, then we just don't get the clouds we need to seed, so it's kind of hard to tell," Moody said.
Some have expressed concern about the effect of cloud seeding on areas downwind from the projects. Wayne Platt, who ranches southeast of Encampment, questioned past effects of cloud seeding projects in Utah and Colorado and how they have affected weather conditions in the Sierra Madre and Snowy ranges.
"It seems to me the more you screw around with nature, the worse off you are," Platt said. "Why not let nature take its course?"
Saratoga rancher Scott Kerbs suggested the project should involve analysis by attorneys of potential effects to the state caused by lawsuits from people who believe they are harmed by cloud seeding.
"Everything upstream (upwind) of us has been sapping the moisture," Kerbs said, suggesting weather modification projects may be an "infringement on interstate commerce."
Marwitz said there is no scientific data about any effects downwind from cloud-seeding projects, but he said from his experience on Elk Mountain in the 1970s, there would be little effect.
How cloud seeding works
The concept: Cloud seeding is a process of adding chemicals - silver iodide - to the right kind of clouds to enhance the potential for snowfall. The clouds seeded are already usually close to snowing, but they may not be able to naturally produce the right type of particles to make that actually happen.
Getting it in the air: Once the chemicals are released into the clouds - through the use of aircraft or from ground-based burners that operate on solar, wind or battery power - wind transports and disperses the agent into the clouds.
What happens: The chemicals cause accelerated ice formation within the cloud, and there is then an increase in the precipitation mass, which leads to increased precipitation on the ground.
Sources: Bruce Boe, Weather Modification Inc., Fargo, N.D., and North American Weather Consultants, Salt Lake City
(More to come.)
