The Delhi government held cloud-seeding trials to test their impact on pollution levels. IIT Kanpur officials said, “We will have to assess data to establish whether our runs contributed in any way.” While last year’s experiments did not induce rain, officials plan to hold more trials after Diwali this year.
Cloud-seeding is a weather modification technique that improves a cloud’s ability to produce rain. Silver iodide (AgI) and other compounds are introduced to initiate microphysical changes in the cloud, encouraging the formation of ice crystals or raindrops. The Delhi government undertook multiple such trials last winter,firing off chemical flares containing silver iodide and sodium chloride compounds. It did not induce rain on any of the experiments held last year.
IIT Kanpur, which is carrying out the experiments on behalf of the Delhi government, said the primarily goal is to not induce precipitation, but to establish a link between seeding and possible reductions in PM 2.5 and PM 10 levels.
“While no runs were held this past week, trial runs were held earlier in October. These were also held closer to the days it rained, but we will have to assess data to establish whether our runs contributed in any way,” an official at IIT Kanpur said,
More trials are likely to take place post-Diwali, whenever meteorological conditions seem favourable, officials have said.
“Even last winter, we looked at data on pollutants before and after a trial run and the same is being assessed. We plan to hold trials after Diwali from the IGI airport. Last year, these took place from Meerut, but there, low visibility was a problem,” the official said.
Multiple government officials told HT that the trials have not stopped since last year.
“We have carried out trial runs even in other seasons too, to gather data on impact on pollution levels.” an official in the government said.
Another senior government official, requesting anonymity, said these latest trial runs were conducted around the airport and adjoining areas.
Delhi environment minister Manjinder Singh Sirsa refused to comment on the matter. However, on earlier occasions, he has not ruled out the possibility of using the technology to address the problem of pollution.
Experts have long called cloud seeding a cosmetic solution to Delhi’s air pollution problem, calling for long-term action against sources of pollution. “Instead, we need focused action on sources of pollution across a larger airshed. This requires coordinated action against agencies too.