Cloud seeding: “It can’t replace dams or conservation” — Joe Busto

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From the Watch (Stephen Elliott):

[Andy VanDenBerg] is one cog in a regional cloud seeding program that purports to increase wintertime snowfall over Telluride by as much as 15 percent; he’s one of the dozen or so landowners from Dolores to the southwest to Disappointment Creek and Saltado Creek further north who have allowed Durango-based Western Weather Consultants to install cloud-seeding generators on their properties, and are paid to operate them when a promising storm system moves into the area.

“It doesn’t make much money. It’s kind of a waste of time and an inconvenience,” VanDenBerg said. “But there’s a chance it works.”

It’s difficult — nearly impossible — to prove wintertime cloud seeding’s efficacy, but that hasn’t stopped the Telluride Ski & Golf Company, Dolores Water Conservancy District, Southwestern Water Conservation Board, Colorado Water Conservation Board, California Six Agency Committee, Central Arizona Water Conservation District, Southern Nevada Water Authority and Metropolitan Water District of Southern California from funding cloud seeding in the Upper San Miguel Drainage Basin, specifically on the Telluride Ski Resort.

“We’re in a 15-year drought and reservoirs are down, so we’re trying to help prevent them from going down further, and maybe bring them back up a little bit,” said Bill Hasencamp, Colorado River Resources Manager for the Metropolitan Water District around Los Angeles.

Hasencamp, like VanDenBerg, can’t be sure cloud seeding works (or at least how well it works), but his agency still enthusiastically funds the program. “There’s a general feeling that it increases snow, but no absolute proof. That’s the tough part: It’s very difficult to tell exactly,” he said.

All of the water managers involved in the Colorado cloud seeding program cite a study from Wyoming when discussing the effectiveness of cloud seeding. The study, conducted by the National Center for Atmospheric Research and several other organizations, was completed in 2014 and compared two mountain ranges in the state: the Medicine Bow and the Sierra Madre. For 10 years, researchers randomly seeded storms in one of the ranges, but not the other, in an attempt to discover if cloud seeding increased snowfall.

That study indicated a 5-15 percent snowfall increase, presumably due to cloud seeding.

“There’s not really any downside to [cloud seeding],” said Joe Busto, cloud seeding program manager with the CWCB. “It doesn’t do a lot, just a few inches more here and there. It can’t replace dams or conservation; it’s just a thing we do every year and we get a little more and that’s all it is.”

[…]

Water managers could conceivably seed clouds anywhere along the Colorado River Basin but have decided to partner with ski areas to boost recreational economies and take advantage of the funding those ski areas are willing to put up for the program.

“Although the state supports [cloud seeding], it’s not just because we want to support all the ski areas. This is a new water source, but it has the great benefit of helping out our recreational economy in Colorado,” said April Montgomery, a San Miguel County-based representative on the CWCB. “This is also a huge benefit to Norwood and the West End. We’re producing more water for our Telluride headwater reservoir, and that’s all going down to the lower ends of the San Miguel, into the Dolores, into the Colorado.”

As reservoirs along the Colorado River, including Lake Powell and Lake Mead, have dried up during the past few years, water managers downstream have turned to more experimental ways to keep them full, or at least less empty. Busto at the CWCB said the out-of-state agencies have contributed nearly $2 million to the Colorado cloud seeding program since 2007.

“The reason why the state is involved in cloud seeding is because it’s the cheapest form of new water. If you look at other ways of creating new water sources, you’re looking at desalinization or you’re looking at giant reservoir systems and new diversion systems. That costs so much money,” Montgomery said. “Our snowpack is the largest reservoir we have and if we can increase our snowpack, we are basically creating this giant reservoir that we can use later.”

[…]

But cloud seeding raises questions. Does silver iodide negatively impact the watershed once it falls out of the clouds? If we coax precipitation from clouds over Telluride, does that mean less will fall on other communities?

Cloud seeding proponents answer a resounding “No” to both questions.

The Wyoming study found silver concentrations in the water after cloud seeding in the parts per trillion range, and in the parts per billion range in soil, “about three orders of magnitude less than values considered hazardous to environmental system or human health.”

“Silver iodide doesn’t dissolve into the water,” Montgomery said. “One reason I’ve been able to embrace this technology is, as we improve and we’re being more efficient and effective with it, we’re not just throwing this up into the atmosphere.”

“This is something that doesn’t bioaccumulate,” Busto added. “When a chemical gets in the fish, then the eagles get it… That’s bioaccumulation. It’s a concern, but [silver iodide] won’t do that.”

As for cloud seeding’s effect on nearby areas, Western Weather’s founder Larry Hjermstad, who has been working in weather modification for four decades, said seeding merely takes advantage of an opportunity in a storm.

“One of the big concerns is, if we’re putting more precipitation in one area, it’s at the expense of another area. The answer is no; we’re creating a slightly better storm system,” he said.

Busto added that winter storms are typically large, often 200 miles long or more, and contain huge amounts of moisture, only a small amount of which will ever fall as precipitation. So when cloud seeding urges slightly more of that moisture out of the clouds, the vast majority of a storm’s moisture remains to fall elsewhere or stick around in the cloud.

“To say you took all the water out of a system that was 200 miles long is really a stretch,” Busto said. “Did you steal that [precipitation] from someone else? No, I don’t think so.”

The Wyoming study concurred, finding that the “downshadow effect,” or the impact of cloud seeding on areas outside the seeded area, was negligible.

#ColoradoRiver: Cloud-seeding supporters are hopeful efforts will fill aquifers and reservoirs — The Durango Herald

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From The Durango Herald (Mary Shinn):

To seed a cloud in Southwest Colorado, employees with Western Weather Consultants light generators that send vaporized silver iodide up to the base of clouds. The silver iodide forms an artificial ice nuclei and attracts supercooled water to form snowflakes.

In an ideal situation, the cloud would release excess water that would otherwise pass over the region, said Eric Hjermstad, co-owner and director of field operations for the company.

“It’s meant to add just a little bit more per storm,” Busto said.

A study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.

During a dry storm or a dry year it’s harder to make a difference, he said.

Seeding during El Niño can help build snowpack to replenish aquifers and help fill reservoirs such as Lake Powell, Hjermstad said.

It’s an investment that is supported by regional water agencies and ski resorts that paid $237,900 this season, according to the Southwestern Water Conservation District. In this area, Western Weather operates about 36 generators from Pagosa Springs to Telluride, Hjermstad said.

This winter, the cloud-seeding supporters are looking to upgrade their efforts through better generators and potentially a radiometer that helps gauge the water and temperature of clouds before seeding, said Ken Curtis, engineer for the Dolores Water Conservancy District.

While he said there’s always skepticism around cloud seeding, the Wyoming study showed that cloud seeding can work if the silver iodide is delivered in the right place under the right conditions.

“We know it works, but you need to do best practices,” Curtis said.

Last week, the Southwest Basin Roundtable granted the group about $55,600 to hire a consultant to help select equipment and the right areas to place it.

The state will review and finalize the grant in the coming months, he said.

The strategic plan to upgrade equipment will likely take two years because there are 12 agencies and companies involved in funding.

#ColoradoRiver: Cloud-seeding impact to SW #Colorado

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From the Associated Press via The Denver Post:

A researcher with the Colorado Water Conservation Board says cloud seeding in southwestern Colorado is helping to squeeze more water out of passing snowstorms, using heaters that vaporize silver iodide to form artificial ice.

In southwest Colorado, workers light generators that look like large propane tanks, shooting flames into pans that send vaporized silver iodide up to the base of clouds. There, the silver iodide forms an artificial ice crystal that draws in more water, forming larger snowflakes. Then they fall to the ground.

“When there’s lots of liquid water coming through, then you have a storm to work. The seeding response is better. You get more bang for your buck,” said Joe Busto, a researcher with the Colorado Water Conservation Board. “It’s meant to add just a little bit more per storm.”

Researchers say a study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.

Eric Hjermstad, co-owner and director of field operations for Western Weather Consultants, which does cloud seeding, said every bit of water helps the parched Southwest.

Hjermstad said seeding helps build snowpack to replenish aquifers and helps fill reservoirs such as Lake Powell for other Western states struggling to find water.

Regional water agencies and ski resorts paid $237,900 this season to help with the seeding, according to the Southwestern Water Conservation District. Western Weather operates about 36 generators from Pagosa Springs to Telluride.

The Southwest Basin Roundtable is providing $55,600 to hire a consultant to help select equipment and find the right areas to place it.

Cloud-seeding gaining favor in arid West — The Durango Herald

From the Cortez Journal (Jim Mimiaga) via The Durango Herald:

Telluride and Purgatory ski areas contribute funds for regional cloud-seeding programs, and so do the Dolores Water Conservation District, Animas-La Plata and Southwestern Water Conservancy districts.

During a meeting Wednesday at the DWCD office in Cortez, an update was given on the regional cloud-seeding program and ground-breaking research recently completed on the technology in Wyoming.

“Interest in cloud seeding has grown, and funding has grown,” said Bruce Whitehead, executive director for SWCD.

Western Weather Consultants provides cloud-seeding services for three programs in the San Juan Mountains including over the Upper Dolores, La Plata, and Animas River basins.

From November 2014 to April 2015, 25 cloud-ice nuclei generators dispersed silver iodide into storm clouds for a total of 875 hours, at a cost of $105,678.

The units are in the vicinity of Cortez, Dolores, Mancos, Mesa Verde, La Plata Mountains, Stoner, West Fork, Groundhog, House Creek, Placerville, Cahone, Lone Cone, Disappointment, Hesperus, Electra Lake, Bayfield, near Purgatory, on the Florida River and elsewhere.

When dispersed in optimum storm conditions, the silver iodide enhances the formation of ice crystals in clouds, forcing more snowfall, said Mike Hjermstad, a technician with Western Weather Consultants, based in Durango.

“The generators are turned on manually, and when the conditions are right, it can increase snow accumulation from a storm by a half inch,” he said…

Cloud-seeding skeptics question whether the procedure actually works because it’s difficult to verify increased snowfall from cloud seeding versus what would fall naturally.

Proponents point to experiments that show areas with cloud seeding had more precipitation compared with control areas that did not get the treatment.

“Detection of very minute levels of silver iodide in the snowpack is also a proof,” Hjermstad said.

Joe Busto, a cloud-seeding permit manager for the Colorado Water Conservation Board, said the environmental impacts of the silver iodide on snowpack is “very low and measured in parts per trillion above background levels.”

He said research shows “strong suggestions of positive cloud seeding effects in winter glaciogenic systems occurring over mountainous terrain.”

Rising costs of new technology such as radiometers, automation, and more snotels is a concern, said Ken Curtis, an engineer for DWCD.

“The funders need to have consensus on where the program is going, if it will be enhanced or stay static,” he said.

Barry Lawrence, of the Wyoming Water Development Office, gave a presentation on a recent groundbreaking cloud-seeding study that showed good results.

The 10-year study cost $15 million and was funded by the Wyoming Legislature.

The elaborate experiment positioned remote-control seeding stations in the Wind River Range and in the Medicine Bow Range.

When winter storm conditions were ideal for seeding in both ranges, only the stations in one range were triggered on. The range without cloud seeding was the control, and then snowpack from both ranges was compared for that storm. Control ranges were alternated throughout the experiment.

Despite some cross contamination in the controls, additional modeling and statistical analyses showed cloud-seeded ranges overall benefited from additional snowfall, Lawrence said.

“Our independent evaluator, the National Center for Atmospheric Science in Boulder, concluded cloud seeding from the experiment resulted in 5 to 15 percent in additional precipitation,” he said.

Encouraged by the results, the Wyoming Legislature recently approved $1.5 million to install operational cloud-seeding stations in the Medicine Bow Mountains and other ranges.

More cloud seeding coverage here.

Can cloud-seeding ride to the rescue? — The Mountain Town News #ColoradoRiver

lowlakemead2012allenbest

From The Mountain Town News (Allen Best):

After a so-so winter, the snow piled up through May in the mountains of Colorado, taking the edge off drought. This takes the edge off of the big Colorado River reservoirs, Lake Mead and Lake Powell. But the overarching story at those reservoirs since 1999 has been of decline, even after a few big years.

In the last several years, there has been increasing talk about the potential for the two reservoirs to become empty. Las Vegas, reliant upon Lake Mead for most of its water, isn’t just talking about the possibility. It is nigh-on to completing a third tunnel into the reservoir, this one at a cost of $817 million and, unlike the others, at the very bottom of the reservoir, in case there’s nothing left of Lake Mead except for the Colorado River. That’s how dire Las Vegas, operating as the Southern Nevada Water Authority, takes this potential of long-term drought.

Eric Kuhn, the manager of the Colorado River Water Conservation District, spoke to the implications of this continuing drought at a forum in Colorado’s Summit County this spring. “Bad things happen when Lake Mead and Lake Powell get drained,” he said in an event covered by the Summit Daily News. He described the draining of Lake Mead as a distinct possibility in the next few years.

What about building a pipeline to the Mississippi River or some other water-rich location? “To expect that we can export our problems to somebody else, I just don’t see that somebody else will willingly accept them,” he said.

How about just making some more water? That effort began soon after World War II in different times of drought. Scientists at General Electric in New York state had discovered the general principle. And in some places of the West, cloud-seeding has occurred since the 1950s – including, at Vail Mountain, since 1978.

But does it work? Since the federal government yanked research dollars from cloud-seeding experiments in the 1980s, relatively little rigorous science had been conducted. Instead, there were the claims of commercial-cloud seeders, who predicted gains of 10 to 15 percent—as long as they had clouds to work with.

In 2004, Wyoming set out to fill that gap. An experiment that ultimately cost $14 million was designed by scientists working for a federal laboratory, the National Center for Atmospheric Research. Parallel mountain ranges southwest of Laramie, just north of the Colorado border, constituted the Wyoming laboratory. Propane was burned to loft silver iodide from ground-based generators into the clouds passing over the Sierra Nevada and Medicine Bow ranges. In the experiment, 154 storms during six winters had the temperatures needed for effective seeding, but only 118 had the moisture content. And of those, 18 were tossed out because of contamination problems.

Slim statistical evidence

Last December, at a meeting room in Cheyenne, scientists delivered the results. It took a full afternoon and the results were sometimes confusing. But hydrologists and meteorologists who listened to the proceedings remotely told me they had no trouble hearing the key statistics: just a 3 percent increase in precipitation but with the 28 percent probability that cloud-seeding had nothing to do with the increase. Only by creating models were researchers able to make a case that snowfall had been augmented 5 to 15 percent.

instumentationcloudseedingresearchcolorado

Taking stock of this and other winter weather-modification studies, the Bureau of Reclamation was unimpressed. “As such,” said the agency in a draft analysis released in February, “the ‘proof’ the scientific community has been seeking for many decades is still not in hand.”

Proof in science requires a 95 percent probability of causality. This is extremely difficult to achieve in complex atmospheric processes, whether cloud-seeding or many of the processes involved with a warming global climate.

In Wyoming, elected officials have decided the evidence to support cloud-seeding is strong enough to justify additional investments in various drainages—including the Wind River Range, which produces water for a tributary of the Colorado River—even as they have been loathe to admit the science of global warming.

Wyoming isn’t alone. Water agencies and cities from Denver to Los Angeles pay for seeding clouds in the mountains of Colorado and Wyoming, and representatives heard what they wanted to hear.

“It’s good evidence that it works,” said David Cole, who administers weather-modification programs for the Utah Division of Water Resources.

“There is always that question, ‘Can you prove it beyond a shadow of a doubt?’” he added.

From Los Angeles comes a similar appraisal of confirmation. “These results are consistent with historic studies,” said Tom Ryan, of Metropolitan Water District of Southern California, a consortium of agencies that collectively serves 18 million people.

I heard similar remarks from the Central Arizona Project, which uses a 336-mile-long system of aqueducts, tunnels, pumping plants, and pipelines to deliver water to Phoenix, Tucson, and cotton farms and golf courses along the way.

Along with Las Vegas, Arizona and California chip in to pay for cloud-seeding in Colorado and Wyoming.

Dan Breed, project scientist with NCAR, said that failing to achieve a 95 percent confidence level in results is not unusual in cloud-seeding studies. The fundamental problem, he says, is the complexity of atmospheric processes.

It’s the same challenge that has prevented most climate scientists from linking specific weather events, such as the September 2013 floods in Colorado, to rising global temperatures and the 3 to 5 percent observed increase in atmospheric moisture related to that warming.

“When it comes to the atmosphere, there are just too many variables, and that variability just keeps rearing its ugly head when it comes to cloud-seeding,” says Breed. “Even in this case, where we tried to make things as homogeneous as possible to reduce that variability, variability still kind of hurt us.”

Breed thinks research might better be invested in understanding specific atmospheric processes of wind, temperature, and precipitation. For example, how likely is it that silver iodide or other seeding agents released from the ground will get into the clouds?

Understandings of atmospheric processes, says Breed, has mostly come from observations, instead of experiments – because of that same variability.

This lack of certainty does not necessarily kill the prospects of cloud-seeding, as is demonstrated by the continued interest of Wyoming legislators in funding cloud-seeding.

Cloud-seeding to the rescue?

Can cloud-seeding the answer to the problems of California, now in its fourth year of drought, or of the Colorado River?

The river is notoriously strapped to meet all of the wants and maybe even the needs. River flows have declined 20 percent in the 21st century as compared to the last century.

Breed disputes conclusions that cloud-seeding doesn’t necessarily work. But he doesn’t see it as a game-changer for the Colorado River. Modifying the weather is a fairly straightforward, quick and inexpensive way to produce more water, but the gains are marginal. “It is not, he says, a magic bullet. “It won’t solve the problem.”

In his appearance in Summit County, Kuhn took a broad view, describing the 21st century as a time of transition. “After 100 years of develop more, develop more, develop more, we’re going to have to cut back our uses.”

That’s the difficult conversation now underway in California as residents in places like San Jose argue about lawn sizes and almond groves. It’s also the more earnest conversation that, despite the extraordinary rains in May, is getting underway in Colorado.

More cloud seeding coverage here.

Wyoming’s 10 year cloud-seeding experiment scrutinized

Cloud-seeding graphic via Science Matters
Cloud-seeding graphic via Science Matters

From the East Oregonian (Allen Best):

Wyoming just spent $14 million and the better part of 10 years on a rigorous scientific experiment to evaluate whether it’s possible to get extra snow from winter storm clouds through cloud seeding. The conclusion? The final results were thin: There was a 3 percent increase in precipitation, but a 28 percent probability that the cloud seeding had nothing to do with it.

Given the results of this and other winter weather-modification studies, the Bureau of Reclamation remains unimpressed. “As such,” said the agency in a draft analysis released in February, “the ‘proof’ the scientific community has been seeking for many decades is still not in hand.”

Proof in science requires a 95 percent probability of causality. But this standard is extremely difficult to achieve in complex atmospheric processes. Climate scientists, for example, mostly resort to asterisk-laden words such as “likely” to indicate lower levels of probability…

From the start, Wyoming’s cloud-seeding experiment was designed to ensure scientific rigor. Parallel mountain ranges southwest of Laramie, just north of the Colorado border, constituted the Wyoming laboratory. Propane was burned to loft silver iodide from ground-based generators into the clouds passing over the Sierra Nevada and Medicine Bow ranges. In the experiment, 154 storms during six winters had the temperatures needed for effective seeding, but only 118 developed adequate moisture content. And of those, 18 were tossed out because of contamination problems.

Dan Breed, project scientist with the National Center for Atmospheric Research, which designed and oversaw the Wyoming experiment, said that failing to achieve a 95 percent confidence level in results is not unusual in cloud seeding studies. The fundamental problem, he says, involves the difficulty of measuring atmospheric processes.

The challenge inherent in the complexity of the data has prevented most climate scientists from directly linking specific weather events, such as the September 2013 floods in Colorado, to rising global temperatures, or even to the 3 to 5 percent observed moisture in the global atmosphere.

“When it comes to the atmosphere, there are just too many variables, and that variability just keeps rearing its ugly head when it comes to cloud seeding,” says Breed. “Even in this case, where we tried to make things as homogeneous as possible to reduce that variability, variability still kind of hurt us.”

Breed thinks research might better be invested in understanding the interaction in the atmosphere of wind, temperature and precipitation. For example, how likely is it that silver iodide or other seeding agents released from the ground will get into the clouds? True understanding of atmospheric processes, says Breed, has mostly come from observations instead of experiments — because of that same variability.

This lack of certainty does not necessarily kill the prospects of cloud seeding, as is demonstrated by the continued interest of Wyoming legislators in funding projects. In the Colorado River Basin, cities and water districts seized upon the modeled projections of 5 to 15 percent snowpack augmentation as justification for continued or even expanded operations. Already, metropolitan Los Angeles, the Central Arizona Project and the Southern Nevada Water Authority, among others, pay for seeding clouds in Colorado, the source of half the water in the Colorado River, and last year they also paid to seed clouds in Wyoming, in the Green River drainage.

More cloud seeding coverage here.

Wyoming reconsiders cloud seeding and potential benefits for ag

More cloud seeding coverage here.