Last summer, as thunderstorms approached Fort Stockton, Texas, a small yellow aircraft flew through the sky on a mission. The plane was equipped with water tanks and special nozzles on its wings and flew under the clouds. At the right moment, it released a spray of electrically charged water droplets into the cloud. The objective is to extract additional rainfall from the West Texas atmosphere. Dan Martin, a research engineer with the Department of Agriculture's Agricultural Research Service who was involved in the development of the technology, stated that water is becoming increasingly valuable and scarce.
This approach to "cloud seeding," which aims to enhance precipitation by releasing special particles into the air, is a modern take on a decades-old technique and is widely used across the western United States, China, Russia, parts of the Middle East, and other nations. It is one of the world's most prevalent forms of weather modification.
The creation of new and advanced cloud seeding methods has become more crucial in recent times. The severe drought affecting many regions globally, compounded by the effects of climate change, has prompted increased attention from researchers, governments, and major corporations toward innovative water management solutions.
Salting the Clouds
Although cloud seeding is relatively affordable compared to other water management options such as desalination, a process that removes impurities from water to make it potable, there is a challenge. It is challenging to conduct experiments that effectively show the technology's efficacy. Despite ongoing efforts to enhance cloud seeding methods, scientists have difficulty determining their efficacy. "Cloud seeding is known to work, but the real question is to what extent?" said Katja Friedrich, an atmospheric scientist, and cloud seeding expert at the University of Colorado, Boulder.
The technology has remained relatively unchanged since its initial demonstration in the 1940s. Clouds are formed when water droplets condense in the sky and certain particles, such as silver iodide and salt particles, have a tendency to attract water or ice and can potentially accelerate the process. These types of particles have been commonly used in cloud seeding for many years.
The concept of using charged water droplets is relatively recent. It is based on a straightforward theory. The bottom of rain clouds contains negatively charged water. If the cloud is hit with positively charged particles, the water droplets will collide and come together, according to Martin. This process, repeated enough times, produces rain. The flights over Texas last summer were part of a USDA research project that has been ongoing for several years. Additionally, research groups worldwide are working on similar initiatives aimed at enhancing the effectiveness of cloud seeding operations.
Project: Electrical Pulses on Clouds
Some of these projects, like Martin's, utilize electrical charges. Researchers at the University of Reading and the University of Bath in the UK used drones to introduce electrical pulses into clouds. This project, which started in 2017 and was funded by the United Arab Emirates, ended last year. Another project funded by the UAE is exploring the use of nanotechnology by releasing specially designed nanoengineered particles into clouds. The UAE is also financing a separate initiative that employs artificial intelligence to develop algorithms for more accurately predicting the optimal weather conditions for cloud seeding.
Since 2018, over a dozen companies, research institutions, and individuals have patented at least 19 cloud seeding technologies or methods, as reported by a review by E&E News. The "aerial electrostatic system for weather modification" developed and tested by Dan Martin, a research engineer with the USDA's Agricultural Research Service, is included in that list. Last March, the Saudi Arabian Oil Co. obtained a US patent for creating rain to support water flooding in remote oil fields.
The process involves seeding clouds using silver iodide or other materials and collecting the rainfall in reservoirs for boosting oil production. WeatherTec AG, a weather modification startup based in Switzerland, charges humidity and clouds with rain-producing ions using large umbrella-shaped devices. A large number of companies, research institutions, and individuals have patented various cloud seeding technologies or methods since 2018, with over 19 patented technologies and methods listed according to a review by E&E News. Some of the notable companies and organizations include the Saudi Arabian Oil Co., WeatherTec AG, and Boeing Co.
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Cloud Seeding Advancements
Most of the recent advancements in cloud seeding research have come from the UAE. The Saudi Arabian Oil Co. obtained a patent for generating rain to support water flooding in remote oil fields, while WeatherTec AG uses giant umbrella-shaped devices to charge humidity and clouds with ions they claim can produce rain. Boeing Co. also received a patent for a system to induce rainfall, but details on its use are not available.
The UAE has been a major player in recent cloud seeding research and has been funding different projects under its Research Program for Rain Enhancement Science (UAEREP) since 2015. The program has awarded grants for up to 11 projects and provides up to $1.5 million in funding distributed over three years. The recent increase in funding has led to an increase in scientific research in this area and has reduced the dominance of commercial companies. With temperatures rising faster than the global average and declining precipitation, the threat of severe droughts has increased in the Middle East, making cloud seeding an important research area.
In the real world, where weather conditions are constantly shifting, that is difficult to accomplish. Statistical studies have been the primary method of choice for scientists for decades. Typically, this entails seeding a cloud in one location while comparing the results of monitoring unseeded clouds in nearby locations. Although less scientifically convincing, these findings are a start.
Cloud-Seeding Efficiency
Cloud-seeding operations may increase rainfall by as much as 15% or 20%, according to statistical studies. However, Friedrich's project, which took place in the Payette River Basin in Idaho in 2017, was fortunate enough to result in an almost flawless experiment. It was able to compare the effects of seeding clouds in the same location for three days straight thanks to the local weather conditions. Scientists estimate that the seeded clouds produced enough snow to fill 286 Olympic swimming pools during that time.
The project successfully demonstrated the efficacy of cloud seeding. However, how well it works is a different matter. It does not demonstrate that the same amount of snow or rain would fall in various locations under various conditions. To help answer those questions, scientists can build models that simulate cloud seeding operations using data from experiments like Friedrich's. However, many research projects continue to rely on statistical studies in the absence of such data.
It doesn't work perfectly. However, a small amount of data appears to be promising. Martin's charged-water technology, for example, has been tested and appears to be twice as effective as traditional cloud seeding efforts. However, cloud seeding has its limitations, even if it can marginally increase Western water supplies. Firstly, it is ineffective during droughts because it requires clouds. Martin stated that as a result, it is a strategy that necessitates extensive pre-planning. Before a drought occurs, it should be utilized to replenish water supplies. Although water managers should have other options at their disposal, cloud seeding may prove to be useful as one tool in the arsenal.
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