When rain clouds rolled in over Fort Stockton, Texas last summer, a little yellow plane flew through the sky. was on duty.
Equipped with water tanks on the wings and special nozzles, the aircraft soared under the grey-white billows. Then, just in time, they released a spray of charged water particles into the cloud.
the goal? To squeeze excess rain out of the western Texas skies.
“Water is very valuable and increasingly scarce,” says Dan Martin, a research engineer with the Department of Agriculture’s Agricultural Research Service, who helped invent the technology.
It’s a twist on a decades-old practice known as “cloud seeding,” or spraying special particles into the air to increase precipitation. It is one of the world’s most popular weather maneuvers and is being carried out in most of the western United States, China, Russia, parts of the Middle East, and other countries.
Developing new and improved forms of cloud seeding has taken on greater urgency in recent years. Severe droughts around the world, exacerbated by the steadily advancing climate change, are sparking growing interest in innovative water management by researchers, governments and large corporations.
Cloud seeding is relatively inexpensive compared to other water management strategies such as desalination. Desalination is a chemical process that removes salt and other minerals from water to make it safe to drink.
But there are pitfalls. Designing experiments to demonstrate how well technology actually works is notoriously difficult (climate wireMarch 16, 2021).
Researchers are working to develop more effective cloud seeding, but scientists say it’s hard to say for sure if it makes a difference.
“There’s no question that cloud seeding works, but the question is how much can you actually produce?” Expert Katja Friedrich says:
Cloud seeding hasn’t changed much since the technology was first demonstrated in the 1940s.
Clouds form when water droplets condense in the sky. Certain types of particles are great at attracting water and ice, which can theoretically help speed up the process. Silver iodide and other types of salt particles have been commonly used in cloud seeding for decades.
However, the idea of using charged water particles is relatively new.
It is rooted in a simple theory. The base of rain clouds is naturally filled with negatively charged water. When they hit the cloud with a stream of positively charged particles, the droplets “collide and coalesce,” Martin said.
“Repeat it enough times and you get heavy rains,” he added.
Last summer’s flight over Texas was the latest test in a USDA research project that has been ongoing for several years. Meanwhile, research groups around the world are working on similar projects aimed at unlocking the effectiveness of cloud seeding operations.
Some, like Martin’s, use electrical charges.
Researchers from the Universities of Reading and Bath in the UK used drones to attack clouds with electrical pulses. Started in 2017, the project was funded by the United Arab Emirates and finished last year.
Another UAE-funded project is experimenting with nanotechnology by seeding clouds with special nanoengineered particles. The emirate is funding another effort to use artificial intelligence to build algorithms that can more accurately predict the types of weather conditions that are best for cloud seeding.
oil rain?
Malaysian military planes are seeding clouds in an attempt to clear the haze from plantation fires in 2019 by shooting water and salt into the sky. AP Photo/Vincent Tian
According to E&E News’ review of international patents, more than a dozen companies, research institutions or individuals have patented at least 19 cloud seeding technologies or methods since 2018. The “Airborne Electrostatic System for Weather Modification” invented by Martin and currently being tested is included in that tally.
Several companies have also expressed interest.
Last March, Saudi Arabian Oil Company, the world’s third-largest publicly traded company by market capitalization, received a U.S. patent for producing rain “to support the flooding of remote oilfields.” bottom. Drillers need water to test wells and increase oil production. But in the desert environment where the company, also known as Saudi Aramco, primarily operates, that resource can be hard to come by.
The process, patented by Saudi Aramco, uses silver iodide or other materials to seed clouds and collect rainfall into reservoirs, which can boost oil production. It is unclear whether the oil giants have deployed this process. Saudi Aramco declined to comment on the matter.
Another example is weather modification startup WeatherTec AG. Based in Zug, Switzerland, with offices in Germany and Jordan, the company uses a giant umbrella-shaped device that charges humidity and clouds with rain-producing ions.
WeatherTec’s patents (obtained from the European Patent Office and World Intellectual Property Organization) appear to be for new devices that have not yet been marketed to potential customers. The company did not respond to a request for comment.
In 2019, US aircraft manufacturer Boeing received a US patent for a “system used to induce rainfall.” A Boeing spokesperson declined to provide details, if any, on how the company uses the system.
According to Friedrich, a scientist at the University of Colorado, much of the recent explosion in cloud seeding research originated in the UAE.
The country has been experimenting with cloud seeding for decades, and the Rain Enhancement Scientific Research Program (UAEREP) has awarded grants to at least 11 different research projects involving weather modification since 2015. increase. .
Crowdseeding research has historically been dominated by commercial companies rather than independent scientists, says Keri Nicoll, a researcher at the University of Reading who is working on a UAE-funded drone project. said in an email. That started to change. Recent funding initiatives like the UAEREP “have advanced research in this area over the last five to six years,” she said.
Temperatures are rising faster than the global average in many parts of the Middle East, and precipitation is declining. Studies suggest droughts will become more severe as the region continues to warm.
“They are investing heavily in cloud seeding for obvious reasons,” said Friedrich. “They need water.”
China, which has also recently suffered a record drought, is emerging as another frontrunner to change the weather. In 2020, the country announced plans to rapidly expand its nationwide weather modification program to cover more than 2 million square miles.
“Not the Holy Grail”
Interest in new cloud seeding technologies is growing in the western US as well. Friedrich attributes this in part to a groundbreaking study she co-authored in 2020. This is her one of the first research papers to quantitatively show that cloud seeding works.
To show a real effect, scientists have to prove that rainfall from seeded clouds would not have happened without the seeds. This requires two sets of experiments with the same types of clouds at the same locations and under the same conditions.
In the real world, where weather conditions are constantly changing, this is difficult to achieve. For decades, scientists have relied primarily on statistical research. This typically involves monitoring unseeded clouds in nearby locations and comparing the results while seeding the cloud in one location. These findings are scientifically unconvincing, but a starting point.
Statistical studies suggest that cloud seeding could increase precipitation by as much as 15-20%.
But Friedrich’s 2017 project in Idaho’s Payette River Basin was a near-perfect experiment. Local weather conditions allowed him to compare the effects of seeding clouds on three consecutive days at the same location. At the time, scientists estimated that the seeding cloud produced snow equivalent to about 286 Olympic swimming pools.
This project effectively proved that cloud seeding works. But how well it works is another matter. It does not prove that the same amount of rain or snow will fall in different places under different conditions.
Scientists can use data from experiments like Friedrich’s to build models that simulate cloud seeding operations to answer those questions. However, in the absence of such data, many research projects still rely on statistical studies.
It’s not a perfect solution. However, some limited data appear promising. For example, testing of Martin’s charged water technology suggests that it may be twice as effective as his seeding efforts in conventional clouds.
Still, even if cloud seeding could slightly increase water supply in the West, it would have its limits. For one thing, it needs clouds, which makes it useless during drought.
That makes it a strategy that requires a lot of up-front planning, says Martin. It should be used to boost water supplies before drought strikes.
“Most people don’t think about the need for cloud seeding when it’s raining enough,” he said. “They think it’s time for drought, but by then it’s too late.”
And since there’s still a lot of uncertainty about how well even traditional cloud seeding technology will work, Friedrich warns, “You don’t want to put all your eggs in this one basket.” .
Cloud seeding can serve as one tool in your arsenal, but water managers should have other strategies in place.
“If I were a water manager, I would consider it,” Friedrich said. “But it’s not the Holy Grail, nor does it really solve all problems.”
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
