The current in Europe drought appeared to be the worst in at least 500 years

The current in Europe drought appeared to be the worst in at least 500 years

Technology  |  Focus On  |  Sustainability

What is cloud seeding, a try to relief from draught

This technique was discovered in the 1940s, and is nowadays used in arid nations to stimulate rainfalls. More than fifty countries have already used it, and many others are planning to give a chance too

EDO, the European Drought Observatory, in its August report overseen by the European Commission, said that 47% of European countries are under warning conditions, with clear deficit of soil moisture, and 17% in a state of alert.

The current drought appeared to be the worst in at least 500 years, assuming final data at the end of the season confirmed the preliminary assessment.

Italy isn’t an exception. The current 2022 ranks in the first half as the hottest year ever with a temperature that is even 0.76 degrees higher than the historical average, but there are also practically halved rainfall along the Peninsula with a decline of 45%.

The most evident climatic anomaly this year occurred in June which recorded an average temperature well +2.88 degrees higher than the average on values close to the maximum recorded in 2003 (according to Coldiretti elaborations on Isac Cnr data which carries out surveys in Italy since 1800).

In UAE water security remains one of the main challenges as the country relies on groundwater for two-thirds of its water needs. The arid nation faces low rainfall level, high temperatures and high evaporation rates of surface water. Paired with increased demand due to high population growth, this puts the UAE in a precarious water security situation, so cloud seeding is actually an important way to stem the problem. The goal is to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. It’s an artificial technique using which moisture present in the cloud is induced with an intention to create rain.

The procedure can be static, dynamic or hygroscopic. The first one involves the presence of silver iodide, which is a chemical, the main ingredient to create rain. Moisture is already there in the rain and silver iodide is able to bring the rain out by dispensing it out. The chemical will react with condensed moisture and rain will be the outcome. There is also a dynamic way where ice crystals and vertical air currents are passed into the cloud, which initiates the process of rain. It is a rigorous process and it’s more complicated than the static one. Result depends on the various stages and is uncertain as well. So it looks like the best one is the hygroscopic method, where a lower portion of the cloud is connected with salt. The time process starts, the size of the salt increases, and slowly, the water will unite with it. This way is the most trusted and promising one. Cloud seeding can be done by ground generators, planes, or rockets. Usually pilots try to avoid bad weather. During the cloud seeding procedure they do exactly the opposite, they fly directly into the heart of the thunderstorm. Cloud seeding technology has been refined nowadays. Radar is used to determine the intensity of a storm and guide pilots away from the worst of the turbulence. More than fifty countries have already used these techniques, and many others are planning to give it a try too. 

The procedure started to be explored around 1940s. In the US, Irving Langmuir (winner of the 1932 Nobel Prize in Chemistry) and his assistant Vincent Schaefer were researching cloud physics and ice nuclei while working at General Electric. One hot day in the summer of 1946, during experiments at Mount Washington Observatory in New Hampshire, Schaefer found that his prototype refrigerator wasn’t cold enough for the tests he wanted to run. Determined to get on with his work, he decided to speed things up and placed a lump of dry ice at the bottom of the cold box. Creating a cloud with his breath he observed a bluish haze that turned into countless microscopic ice crystals, creating a dazzling effect in the strobe-lit chamber. The sudden change in temperature had spontaneously produced ice nuclei.

On November 13, 1946, Schaefer and his pilot Curtis Talbot took off from New York’s Schenectady airport and, after a 60-mile easterly chase, scattered six pounds of dry ice in a fleecy cloud four miles long that was floating over nearby Massachusetts. Almost at once, the cloud, which had been drifting along peacefully, begun to writhe as if in torment. White pustules rose from its surface. In five minutes the whole thing melted away, leaving a thin wraith of snow. According to Schaefer’s lab notebook, “while still in the cloud, as we saw the glinting crystals all over, I turned to Curt and we shook hands as I said, ‘We did it!’”

Over half a century later, the technology has evolved but the basic principles remain unchanged. In 2011, National Geographic News reported that Meteo was using “arrays of 33-foot (10-meter) electric towers” that “supercharged” clouds, much to the disbelief of international weather experts. Fox News added that “secrecy seems to be the hallmark of company, which requires a password merely for access to their web site.”

Websites run by Meteo Systems and its owner (Singapore-based clean energy investors Sindicatum) openly provide data, descriptions and photos of the UAE ionization trials and even name the technology’s investment budget to date $18 million. Nowadays there are four aircraft available with their own pilots, a radar network and over 60 weather stations. 

During an average four-hour operation, up to 24 clouds can be seeded at a cost of around $5,000. If proven effective, this would compare well with desalination where the cost of the plant alone can exceed $850 million. Given that a medium-sized cloud holds over 400 million litres, one seeding operation resulting in 10% more rain could yield $100,000-worth of water.

The process of cloud seeding can be considered somehow natural, but the worldwide experts have so many different opinions about the consequences, so let’s see what is going on in the future.

Patrizia Marin - Journalist and chairman of Marco Polo Experience, an agency in strategic communications, public affairs, marketing and media relations, with twenty years of experience in business internationalization, communication, media relations, mapping of the decision makers and community of interests’ relations. She has been advisor to the Italian Presidency of the Council of Ministers for Communication, Publishing and Information. In the logistics and infrastructure sectors, she has been Head of Communications for the Venice Port Authority; Media Relations Consultant for Aeroporti di Roma; International pr advisor for Atlantia while Vice-President at FBC. Patrizia is contract professor in Leadership and International Relations at the IULM University and has a degree in Law and International Political Science.

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