New Delhi:
Cloud seeding over Delhi for an entire winter would cost approximately Rs 25 crore, and this sum is a small portion of the budget to tackle the air pollution in the national capital, IIT Kanpur director Manindra Agrawal has told NDTV.
The senior academic was speaking a day after an expert team from IIT Kanpur oversaw two sorties of cloud seeding in Delhi. These trips, however, did not lead to rain.
The IIT Kanpur director said that cloud seeding did not cause rain yesterday due to low moisture content in the clouds over the national capital. The moisture content yesterday was around 15 per cent, and it must be around 50 per cent for cloud seeding to be successful.
Highlighting the takeaway from yesterday’s exercise, Agrawal said the IIT team had installed measurement equipment at 15 locations in the national capital, and they recorded a 6 to 10 per cent decrease in PM 2.5 and PM 10 pollutants.Cloud seeding is a weather modification technique, mostly used to cause rainfall in parched areas. This involves spraying tiny particles such as silver iodide or chloride onto clouds. Aircraft or drones can be used to carry out cloud seeding. Once sprayed or injected into clouds, these particles act as nuclei for water droplets or ice crystals, causing precipitation or rain. The results, however, depend on multiple factors such as cloud type, temperature, moisture, and wind.
Agrawal said a very finely ground mixture is used for cloud seeding. “In this mixture, there are particles of common salt, rock salt, and silver iodide. We inject it into the clouds. So every small particle of it begins to condense water all around it. And when the condensation occurs in excess, it falls like a drop. And when a lot of drops fall, rain happens,” the scientist said.
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