In an attempt to deal with the ongoing drought in the western United States, a team of scientists is planting clouds over mountains to try and get snow to fall more often.
The Western states are facing the worst drought in 1,200 years, leaving 61% of the contiguous United States facing water scarcity and dry conditions.
There are a number of efforts to address this issue, including covering waterways with solar panels in California, but another way is to try to make it snow.
The concept of cloud seeding, where chemicals are placed in clouds to stimulate the formation of snow and raindrops, has been used since the 1940s.
This is a common practice in China, and due to the ongoing drought, it has become more common in the US, especially in Utah and North Dakota, where planting has been going on for nearly five decades.
Wyoming is relatively new to seeding, having started testing in 2003, but it has intensified this season, with 28 cloud seeding flights over mountainous areas, CNN said.
The team behind the cloud seeding program in Wyoming describes it as storing water, not in vats, but as snow on mountaintops during the winter months.
In an attempt to deal with the ongoing drought in the western United States, a team of scientists is planting clouds over mountains to try and make snow more frequent.
The concept of cloud seeding, where chemicals are placed in clouds to stimulate the formation of snow and raindrops, has been used since the 1940s. stock images
While cloud seeding has been shown to increase snowfall – to a limited extent – it is not a solution to the ongoing devastating drought in the region.
Julie Gondzar, program manager for the Wyoming Weather Change Program, told CNN not everyone is a fan of the cloud seeding effort, with some claiming her team is “playing god” and “stealing moisture from the storm.”
She said a cost-benefit analysis is being done to decide whether the effort needed to seed the clouds, including any loss of moisture elsewhere, is worth it.
At the moment, because there is so little water in the region, teams of scientists are doing everything possible to get water, including increasing the amount of snowfall.
“Think of it as a reservoir of water, but on top of mountains in winter,” she said.
Cloud seeding season is four weeks away before the winds die down by summer and it becomes more difficult to grow snow crystals.
To seed the cloud, they inject silver iodide, adding tiny particles called ice nuclei. Water needs these particles to freeze and produce rain.
Artificial ice made from iodide produces higher levels of precipitation than a natural cloud if left to its own devices.
There are two main mechanisms used by US cloud seeders – one from the ground and one involving aircraft to place it directly into the cloud – both use silver iodine as the seed agent to start the process.
The Western states are facing the worst drought in 1,200 years, leaving 61% of the contiguous United States facing water shortages and dry conditions.
“Ground generators look like small weather stations, about 20 feet tall, and they spray into the atmosphere,” Gondzar told CNN.
“But you have to wait for the right atmospheric conditions for the plume to pass over the mountain range.” This makes the process more difficult as it is highly dependent on wind direction, she explained.
The other mechanism, and the more common of the two, is aircraft, using flares on the wings with silver iodide in a cardboard sheath, as well as flares on the belly.
HOW IT WORKS: CLOUD POPULATION
Silver iodide particles are ejected directly into the cloud or upwind over a mountainous area.
Silver iodide promotes the natural formation of ice crystals in the cloud by creating artificial ice nuclei.
They mimic natural nuclei found in water droplets that allow water and ice to form around them.
These new ice crystals become larger than they might otherwise be, forming snow that can fall.
The snow then falls on the mountainous region where it otherwise could not fall or in greater quantities.
As the weather warms up throughout the year, the snow melts, creating runoff to replenish rivers, lakes, and reservoirs.
Mountains act as a natural water storage system, and using cloud seeding increases the overall supply.
Research shows that Wyoming has 2% more water with cloud seeding than without it.
The cardboard hulls ignite when a plane hits a storm, spreading silver iodide into the clouds and creating higher levels of humidity – and more rainfall.
Gondzar said it was a natural process because the silver iodide they use is just a naturally occurring salt compound that has a regular geometric shape at the molecular level.
This shape is like an ice crystal that tricks the cloud into producing more ice crystals, which then in turn turn into snowflakes, causing snowfall.
While this helps improve and increase snowfall, it is not a solution to drought caused by much less rainfall and higher than manageable demand for water.
“Cloud seeding does not eliminate drought,” Gondzar told CNN. “You cannot stop a drought by sowing clouds. It’s a tool in a toolbox.”
They can’t even tell exactly how much more snow they’re producing, it’s just more than could be produced naturally, as “the evidence is on the radar.”
“The question they are now trying to answer is how well does it work? And this is a difficult question. Because there is an abstract part of it. It’s really impossible to know how much snow any given system would produce.”
Even if it’s just a small amount, in drought conditions even that can make a difference, she said, especially since the numbers show Wyoming had 60 percent of average snow cover last winter.
Since most of the water for the west comes from snowmelt in the mountains every spring, this exacerbates the problems caused by drought.
This is why the small amount of extra snow that forms over the winter matters.
“It’s a small gradual change over a long period of time. That’s why consistency is so important,” Gondzar said, defending the program, which costs $28 per acre foot of seeded clouds.
“These numbers tell us that this is an inexpensive way to add water to the system. We are essentially creating a little extra snowpack that becomes extra river flow in the spring and summer,” she told CNN.
While cloud seeding has been shown to increase snowfall – to a limited extent – it is not a solution to the ongoing devastating drought in the region. Stock image of Wyoming
The megadrought hitting the southwest is the worst the region has seen in 1,200 years, researchers say.
The megadrought that has devastated the southwestern United States and parts of Mexico over the past two decades is the worst drought the region has seen in at least 1,200 years, according to a study released Monday.
Researchers at Nature Climate Change analyzed tree rings, which determine soil moisture levels over a period of time, and concluded that the current megadrought is worse than the one that hit the region in the late 1500s and is the worst since 800 year of our era.
The study, which analyzed a region stretching from southern Montana to northern Mexico and from the Pacific to the Rocky Mountains, found that human-induced global warming accounts for more than 40% of drought severity.
“A drought at the turn of the 21st century would not have been a megadrought trajectory without anthropogenic climate change,” according to a study by Pak Williams, an assistant professor at the University of California, Los Angeles.
Source: AFP
However, drier weather brought on by climate change makes things more difficult because the process requires the cloud to be already in the sky — it can’t come out of thin air.
“The silver iodide in the cloud initiates this snow,” Gondzar explained. But you can’t make snow out of nothing. There must be supercooled liquid water in the cloud.”
“Essentially, we’re just playing with cloud dynamics and cloud physics at an ultra-small scale.”
“There’s always a huge flow of moisture that our systems plug into, and cloud seeding is likely bringing up to 2% more moisture to the surface.”
Daniel Swain, a climate scientist at the University of California, Los Angeles, told CNN there are other mechanisms that are better used to solve the problem, especially since the process involves deploying a fossil fuel-powered aircraft in the clouds.
This, he says, runs counter to broader climate goals of reducing fossil fuel emissions with minimal additional water.
Sara Tessendorf, a scientist at the National Center for Atmospheric Research, told CNN that fossil fuels are a small price to pay for improved technology.
“I will say that the number of aircraft and the duration of these cloud seeding flights, and the programs that are currently doing so, pale in comparison to the number of commercial flights and aircraft that we have in the skies around the world right now. ,’ she explained.
“So for me, this is a drop in the ocean of additional fossil fuels being burned. But that doesn’t mean there’s no room for improvement to make the process cleaner.”
“Controlled studies are needed that actually show that it was planting that significantly increased rainfall,” Swain said.
“At best, this is a small incremental addition to other water-saving or water-saving measures during periods of shortage, but even that is not clear if this will actually work in this capacity in any systematic way.”