Cloud Seeding

Cloud Seeding has been around for about 80 years. Here in Idaho it’s used in the winter to generate snow, which means more water for irrigation and for power generation.

Some people have concerns about how cloud seeding works and whether it is safe. This video tries to answer the basic questions people have.

Verbatim:

(Augustus Doriko,  CEO of Rainmaker) “If you look at the state of water supply in the American West, right, Some years it's a boom year, some years it's a bust year, but decade over decade, there's less snowpack in the mountains, there's less flow in the rivers, there's less water in the aquifers, right? Like these things are all more and more true every year. “

(Jeff Raybould, Idaho Water Resource Board)  “We all need more water. Whether we live in town or we live out on the farm, we need to have adequate water for our needs.”

In Idaho much of that needed water comes from snowpack, and cloud seeding is used to help increase snowfall. Even though cloud seeding has been around a long time, some folks have concerns about how it works and whether it is safe. We’ll try to give the basics in this video.

First, WHAT IS CLOUD SEEDING?

Could seeding began in the late 1940’s when scientists were researching icing on aircraft. They discovered tiny particles could be used to produce ice. First using a freezer and dry ice they were able to create snow in a laboratory, later testing it on a real cloud  in 1947. They later discovered that silver iodide was even more effective at generating ice formation. 

So HOW DOES IT WORK?  First, you need a cloud… more specifically… a storm cloud.

(Derek Blestrud, Idaho Power Senior Atmospheric Scientist) “Every storm can't be seeded. We need a storm, first of all, to seed, but then that storm has to have specific weather conditions that are suitable for seeding.”

Snow is produced naturally when supercooled liquid water latches onto airborne microscopic particles like dust or pollen. The water vapor transitions into ice on these particles, forming crystals, which when heavy enough fall through the atmosphere as snowflakes. If the storm doesn’t have enough of these particles, the storm can’t make any snowflakes. So cloud seeding helps it along with a different ingredient.

(Derek Blestrud, Id Power) “The main seeding active ingredient that we use is called silver iodide on the molecular scale. It's hexagonal in shape, so it mimics an ice crystal. So it's a really good particle to teach a  water droplet to freeze and eventually become a snowflake that can fall to the ground.”

Again, they need existing clouds that contain water. They cannot create moisture from nothing. They can use both ground-based cloud seeding and aircraft based cloud seeding, including a newer method using unmanned drones.

Teams of meteorologists have refined the process over the years, from developing better forecasting and satellite imaging, to more accurate radar targeting of potential storm clouds, and determining which clouds are better seeded from the ground and which from the air. 

So WHY IS IT NEEDED?

Cloud seeding is used for rain or for hail mitigation in some parts of the country, but here in Idaho it’s used in the winter to add to the snowpack, which can help mitigate droughts like this year. More than half of the state’s cropland is irrigated, which produces nearly 80% of the total agricultural crop value, primarily in Southern Idaho.

Besides helping fill the reservoirs for irrigation of farmland, it also helps hydroelectric power generation through dams that helps keep electricity costs low, as well as help provide for towns and cities across the state that depend on a reliable water supply.

(Jeff Raybould, IWRB) “One of the goals of the program is to have a more reliable water supply for irrigators for ag. And if ag has a more reliable water supply, they're going to be able to produce more and provide more economic activity. That's a direct benefit to rural communities and schools and everything that goes along with that.”

One of the big questions is, HOW WELL DOES IT WORK?

There was a study here in Idaho in 2017 specifically designed to prove whether cloud seeding with silver iodide works. It was called the Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment. Or the SNOWIE project, for short.

(Derek Blestrud, Id Power) “Throughout my time here, some of the most exciting and advanced developments that we've had was working on the SNOWIE project. It was the National Science Foundation project. And during that event, there was several different storms that we seeded that we may not have typically seeded, but since we were really trying to identify what is the best time to seed, we seeded some lesser producing storms. And with that, we got radar returns that showed the seeding signature in it. And this was the first time that it was recorded that you had a seeding event happen, and then you could see it on a radar image. It was pretty fun to watch university professors that have been looking at cloud seating for years, like some of them were 30 years plus, and they'd never seen that, and they're jumping up and down in the room. Getting that definite cloud seeding works image was pretty fun to see.”

Rates of increased snowfall after cloud seeding varies, but in Idaho generally averages around 10%.  And the numbers show it’s more cost effective than efforts like building dams and reservoirs.

(Jeff Raybould, IWRB)  ”It's really an opportunity to get more water in the state of Idaho at a relatively economical price compared to trying to store that additional water in surface storage or even aquifer recharge projects, when the abundant supply is there, by having a little extra water all the time, we're able to utilize that at a much lower cost than otherwise would be the case if we had to build out storage, for example.”

(Derek Blestrud, Id Power) “The amount that we spend on our cloud seeking projects versus the amount of water that's produced equals about a $4 acre foot of water for that additional water that we have.”

An acre foot of water translates to the entire square footage of an acre, which is about the same as a standard football field minus the end zones, covered in water one foot deep.

(Jeff Raybould, IWRB) “It's a lot cheaper to cloud seed and let that water sit on the mountain and come down as needed.  Projects that we have in the works, Anderson Ranch, those projects are in the thousands of dollars per acre foot to build.”

One of the main concerns people have about cloud seeding, IS IT SAFE? People have understandable concerns about environmental and health impacts on water and wildlife.

(Augustus Doriko,  CEO Rainmaker) I am super sympathetic to people that have questions about cloud seeding, right? A lot of people haven't heard of it ever before. A lot of people that might have heard of it aren't sure exactly how it works or what goes into it. So those questions make a lot of sense. Is it safe? What's going on? How does it work?

(Derek Blestrud, Id Power) “The greatest part about silver iodide is it's insoluble in water, and that's why it works as a good seeding agent. It stays intact when that water hits it. It doesn't dissolve, and then that can grow the snowflake. And it also is good that way because once it falls to the ground and the tiny amounts that, the trace amounts that do fall in the snowpack, they’re not available for aquatic organisms to ingest and intake, and that's why it's a safe manner for cloud seeding.”

(Augustus Doriko,  CEO Rainmaker) “Cloud seeding was invented 80 years ago in the United States in 1946. And because it was invented so long ago, Programs have been running at a small scale for decades. And even though we weren't able to prove how well it was making precipitation until recently, we were able to prove with 80 years of data that the material we're using is safe because of how little of it is getting into the precipitation and watershed. When we use about 50 grams of silver iodide in an operation, about as much as you can fit in your hand, That gets distributed over 10s of square miles, if not hundreds. And the concentrations of silver iodide in the water that comes down is about 8 parts per trillion. The amount of silver in American soil is already about two parts per million. So we're way below that problematic threshold. And then the clean water drinking standard is 100 parts per billion. We're still about a million times less than that. And so, does it make sense to ask if Silver iodide is safe? Absolutely. But what does the data say about it? That it is absolutely safe and has no adverse effects for the environment, for agriculture, or for human health.” 

(Jeff Raybould, IWRB) “There's no indication of any negative environmental consequences from putting the small amounts of seeding material out there that we use. And in the areas where we use it, where that material lands, is in remote mountain locations. We're not seeding over to have that material come in contact with cities and residential areas.”

Another substance used in cloud seeding that people have raised concerns about is acetone. It’s burned to release the silver iodide in both the nozzles and flares from an aircraft release and also ground units. However, when it’s burned, it converts to water vapor and carbon dioxide posing no danger to the environment.

(Jeff Raybould, IWRB) “There's a fair amount of misinformation out there. And I would like to ask Idahoans to, if they have questions, to go and look, go to our website and look at all the materials that are there. We've done extensive research as we've invested in cloud seeding as a water board.”

Some states have banned could seeding or are considering bans over fears about silver iodide, as well concerns about contrails, the long streaks of water or vapor condensation trails left by aircraft at high altitudes produced by aircraft engine exhaust and changes in air pressure.

Conspiracy theorists say that contrails are actually chemtrails, clouds of chemical or biological agents dumped on the unsuspecting public for nefarious purposes. Different motives are ascribed, from weather control to mass poisoning.

Other concerns include fears of causing unintentional flooding and also possibly stealing water from neighbors downwind of cloud seeding operations. Both of these concerns are not supported by any evidence, and experts note that seeding only uses a tiny percentage of the moisture in the cloud.

This map shows active programs in Idaho right now.

Today a partnership between Idaho Power, Water Users and the state work together in a collaborative program to manage cloud seeding operations, which must be licensed by the state through the Idaho Water Resource board, as well as mandatory federal reporting to the National Oceanic and Atmospheric Administration. (NOAA)

(Jeff Raybould, IWRB)  “We've developed a relationship where the water users pay a portion of the cloud seeding costs, and the water board pays a portion, and Idaho Power pays a portion. And it's a win-win-win proposition. In years of plenty, a lot of the water goes to Idaho Power. In scarce years, nearly all the water goes to water users. And it's worked really well.”

WHAT WILL CLOUD SEEDING LOOK LIKE IN THE FUTURE?

One of the more recent developments is the use of drones for cloud seeding. Rainmaker is a company that has developed drones specifically designed to better target storm clouds. They have built in sensors and can fly into high winds up to about 45 knots, and have anti-icing systems with heaters on the drone propellers.

(Augustus Doriko,  CEO Rainmaker) ”The best conditions, the conditions in a cloud that you can get the most additional water on the ground from are the most meteorologically severe. The worst the icing is, generally speaking, even the worst the winds are. the worse the turbulence is, the better it is for cloud seeding. The more snow you can put on the ground from flying into it. And so the beefier we can make this, as beefy as we have made it already, the more conditions we can get into and the more water we can put on the ground.”

They operate in the Bear River drainage in Southeast Idaho using both ground-based generators and drones. Other areas in Idaho are also being looked at for possible new cloud seeding programs.  Some companies are also looking at new technologies like using electrically charged water or organic particles instead of silver iodide.

(Augustus Doriko,  CEO Rainmaker)  “What excites me about cloud seeding, why I think this is such a good and important thing, is because we can bring new supply to these areas that never would have been able to have it before.”

(Jeff Raybould, IWRB) “We want the public to be informed and to know what's going on with cloud seeding. We have a website that has a lot of information about the program, the current status of the program, links to information about the history of cloud seeding and the general aspects of cloud seeding that they can go and find out for themselves what's happening so that they have a clear understanding of the benefits from the program.”