The Delhi government is all set to conduct cloud seeding experiments to induce artificial rain in an effort to combat the rising pollution in the national capital. Chief Minister Rekha Gupta announced on Thursday that all preparations for the project have been completed, and a successful trial was carried out in the Burari area. She said that if weather conditions remain favourable, Delhi could witness its first artificial rainfall on October 29.
What is cloud seeding?
Cloud seeding is a weather modification technique designed to increase rainfall or snowfall by stimulating the formation of precipitation within clouds. This is achieved by introducing cloud condensation nuclei (CCN) or ice nuclei, which encourage the growth of raindrops or snowflakes.
Various seeding agents are used depending on the type of cloud and temperature. Silver iodide is commonly employed to promote ice crystal formation in colder clouds, while sodium chloride helps water droplets form in warmer clouds. In certain cases, potassium iodide or dry ice may also be used as effective alternatives.
Aircraft can release the particles directly into the targeted clouds. Alternatively, ground-based generators release particles that rise into the atmosphere and eventually reach the clouds. Once introduced, these particles attract surrounding water vapor, causing droplets or ice crystals to form and grow. As these particles become larger and heavier, they eventually fall to the ground as rain.
Cloud seeding practice in Bangkok
Bangkok has been using cloud seeding to combat severe air pollution, especially PM2.5 particles. In December 2024, Thailand’s Royal Rainmaking Department and Air Force deployed Cessna aircraft over Chon Buri and Chachoengsao provinces, producing light rain that dispersed pollutants and improved Bangkok’s air quality. Part of the annual royal rainmaking program, Thailand conducts thousands of artificial rain flights, with a success rate over 95 per cent, making it a global leader in weather modification.
Cloud seeding experiments in Beijing
Beijing employs cloud seeding as a key component of China's extensive weather modification program. Managed by the Beijing Weather Modification Office, this initiative utilises silver iodide, dispersed via rockets and artillery, to enhance precipitation, reduce hail and mitigate dust storms. Notably, during the 2008 Summer Olympics, over 1,000 rockets were launched to ensure clear skies for the opening ceremony. The program has also been instrumental in combating droughts and improving water supply in arid regions.
Other countries involved in practice
Several other countries have also resorted to cloud seeding for various purposes. UAE has invested heavily in cloud seeding since 2010 to increase rainfall in desert regions. Studies show measurable increases in rainfall in some regions.
The United States also implemented this program in drought-prone areas. Results were mixed but some programs report 5–15 per cent increases in local rainfall.
