Low moisture content in clouds did not cause rain despite seeding: IIT-Kanpur director

New Delhi, Oct 29 (PTI) IIT-Kanpur Director Manindra Agrawal on Wednesday said that although the cloud seeding trial in Delhi did not bring rain, it provided useful information, and asserted that the cost of the process was not much compared to the money spent on pollution control measures in the city.

The Delhi government conducted two cloud-seeding trials in Burari, north Karol Bagh, and Mayur Vihar on Tuesday in collaboration with IIT-Kanpur, but there was no rain. Minimal rainfall was recorded in Noida and Greater Noida after the trials.

"The trial was conducted over an area of 300 square kilometres. The overall cost of that, in my rough estimate, came to around Rs 60 lakh. It roughly comes to around Rs 20,000 per square kilometre.

"If we conduct the exercise over an area of 1,000 square kilometres, the cost would be around Rs 2 crore," Agrawal explained in a video statement.

Delving into further details, he said if it is conducted over the entire winter period, and it is assumed that clouds are present once in 10 days, the cost would come to around Rs 25 to Rs 30 crore.

"That, in the overall scheme of things, is not a very large amount. The amount of money spent on pollution control in Delhi is quite large," the IIT-Kanpur director said.

He asserted that in the absence of a lot of cloud moisture, the possibility of inducing rainfall got reduced.

"It (moisture content) was only around 15 per cent. With that low moisture content, the possibility of making rain is very low. We did not achieve success from that perspective, but we got a lot of useful information.

"We set up 15 stations at various locations to measure air pollution and moisture levels. There has been some reduction in PM 2.5 and PM 10 concentrations. Even with a low level of moisture, seeding does have some impact, albeit not the same that one would ideally like to see," he said.

As part of trials, a finely ground mixture of common salt, rock salt and silver iodide was injected into clouds to induce rain.

Around each tiny particle, water starts condensing, he said, adding that once there is condensation, water droplets form. Once the droplets are in a sufficient number, rain occurs, Agrawal said.

A cloud-seeding trial scheduled for Wednesday in Delhi was put on hold due to insufficient moisture in the clouds. PTI SLB MHS SLB NSD NSD