Cloud Seeding in Delhi Achieves Limited Success, Director Reveals Reason

IIT Kanpur Director Manindra Agarwal explained that Tuesday's cloud seeding efforts to combat Delhi's choking air pollution yielded limited success due to insufficient moisture in the targeted clouds, describing the technique as an emergency measure rather than a reliable fix. In an exclusive interview with NDTV, Agarwal noted that the operation involved firing 14 flares containing a mixture of 20% silver iodide, rock salt, and common salt from a Cessna 206H aircraft that took off from Kanpur's airstrip, covering a 25-nautical-mile corridor between Khekra and Burari in northwest Delhi.

Despite the anticipation following the Delhi government's September 25 MoU with IIT Kanpur—valued at ₹3.21 crore for five trials between October 1 and November 30—the results were underwhelming. "There hasn't been any significant rain so far," Agarwal stated, attributing the shortfall to clouds holding only 15-20% moisture, far below the 50% threshold ideal for effective seeding. He added that conflicting weather forecasts had raised hopes, but on-site assessments confirmed the low humidity, reducing the likelihood of precipitation. The trials, delayed multiple times earlier this year due to unfavorable conditions, marked the second attempt after an initial run on October 23.

Agarwal remained optimistic, announcing two additional sorties scheduled for Wednesday morning when forecasts predict higher moisture levels. "This trial has bolstered our team's confidence to proceed," he said, emphasizing that the exercise provides valuable data for refining the process. The aircraft's flights, coordinated with Chakeri Air Traffic Control, involved dispersing 3-4 kilograms of seeding material in the first phase and 4 kilograms in the second, around 3 p.m. Environment Minister Manjinder Singh Sirsa confirmed the operation's completion, noting it tested feasibility in suboptimal conditions of 10-15% moisture.

Also Read: Delhi’s First Cloud Seeding Trial to Tackle Toxic Air may Begin Today if Weather Clears in Kanpur

The Delhi government hailed modest gains in its preliminary report, recording trace precipitation—0.1 mm in Noida and 0.2 mm in Greater Noida at 4 p.m.—and reductions in particulate levels. Pre-seeding PM2.5 readings stood at 221, 230, and 229 micrograms per cubic meter in Mayur Vihar, Karol Bagh, and Burari, dropping to 207, 206, and 203 afterward. PM10 levels similarly fell from 207, 206, and 209 to 177, 163, and 177. "These changes indicate some localized improvement," the report stated, though critics question the scale amid Delhi's AQI hovering in the 'very poor' category at 305 near India Gate.

Agarwal was unequivocal about cloud seeding's limitations: "It is an SOS solution for crisis situations like high pollution, not a long-term strategy." He stressed that addressing root causes—such as vehicular emissions, stubble burning, and industrial output—remains essential. "Ideally, we should eliminate the need for such interventions by curbing pollution sources entirely," he remarked. Costs, currently elevated due to flights originating from Uttar Pradesh, could drop significantly with local basing, making it more viable for occasional use.

As Diwali smoke lingers and non-BS-VI commercial vehicles face entry bans from November, Agarwal underscored the broader benefits: "Even delayed rain offers temporary relief to residents gasping for clean air." With visibility challenges in Kanpur delaying earlier takeoffs and the DGCA's permissions in place, Wednesday's trials could finally deliver the artificial downpour Delhi desperately needs.

Also Read: Toxic Smog Blankets Delhi, Residents Struggle as AQI Soars Over 300