What is artificial rain and could it be the answer to Delhi’s pollution woes?

Delhi continues to breathe toxic air. The overall air quality index (AQI) in the National Capital improved marginally to the ‘very poor’ category on Tuesday (7 November) morning as compared to ‘severe’ in the last few days, according to the System of Air Quality and Weather Forecasting and Research (SAFAR). The deteriorating air quality has triggered a rise in respiratory problems among the Delhiites. “This is a problem that comes up every year. We see a surge in patients with respiratory issues during this time,” Dr Randeep Guleria, former director of All India Institute of Medical Sciences (AIIMS), said recently. Several curbs have already been enforced in the city to tackle the rising air pollution. The Indian Institute of Technology (IIT) Kanpur has developed another method that could reportedly bring short-term relief to the National Capital. What is IIT Kanpur’s potential solution for Delhi’s air woes? How does it work? Let’s understand better. IIT Kanpur’s solution for Delhi IIT Kanpur is reportedly ready with the technique to induce artificial rains to bring down pollutants and dust in Delhi. As per an Economic Times (ET) report, the premier institute has been working on to develop artificial rains since 2018. In June this year, IIT Kanpur successfully carried out a test to produce artificial rain through cloud seeding. It has obtained the required permissions from government authorities, including the Directorate General of Civil Aviation (DGCA), for the technique, the report added. Speaking to ET, Manindra Agrawal, professor at the computer science and engineering department of IIT Kanpur, said artificial rains can bring respite for Delhi-NCR residents from air pollution for up to a week. However, to kickstart the process of creating artificial rain, there must be specific meteorological conditions. “At our end, we are ready to conduct this in Delhi, but for cloud seeding to create artificial rains, we also need necessary meteorological conditions like clouds with necessary moisture, winds, etc,” Professor Agrawal told the newspaper. [caption id=“attachment_13359092” align=“alignnone” width=“640”] Hygroscopic flares are released during a cloud seeding flight operated by the National Center of Meteorology, between Al Ain and Al Hayer in United Arab Emirates, 24 August, 2022. Reuters File Photo[/caption] Besides the DGCA, the institute also needs permission from the Ministry of Home Affairs (MHA), and Special Protection Group (SPG) – which is responsible for the Prime Minister’s security – to fly an aircraft over the National Capital, ET reported citing Agrawal. Earlier in September, Delhi environment minister Gopal Rai had said the government will explore ways to implement cloud seeding as part of its winter action plan to tackle air pollution. “Experts from IIT-Kanpur also gave a presentation on how artificial rain can be produced. We have requested them to prepare a detailed presentation outlining various facets such as implementation and financial burden,” Hindustan Times (HT) quoted him as saying at the time. ALSO READ: Can masks save people from Delhi’s hazardous air pollution? What is artificial rain and cloud seeding? Artificial rain is induced by increasing precipitation in the clouds by adding chemicals. Cloud seeding is a weather modification technique to produce snow or rain artificially. The method involves spraying particles of salts like silver iodide and chloride on clouds using special aircraft, rockets, or dispersion devices kept on the ground, according to Mongabay India. There are two ways to implement cloud seeding. As per The Conversation, “One is to seed supercooled clouds with silver iodide or dry ice, causing ice crystals to grow, consume moisture from the cloud and fall as snow or rain. It might be shot into the clouds in rockets or sprayed from an airplane or mountaintop. The second involves warm clouds and hygroscopic materials like salt particles. These particles take on water vapor, becoming larger to fall faster.” [caption id=“attachment_13359162” align=“alignnone” width=“640”] Artificial rain can help in bringing short-term respite from Delhi’s pollution woes. PTI File Photo[/caption] How does it help? Cloud seeding has been implemented for various reasons – to lessen the impact of droughts and hail damage, mitigate forest fires, increase precipitation, and improve air quality by dispersing pollutants. A 2017 survey by World Meteorological Organization found that cloud seeding is being deployed mostly to tackle water shortages affecting agricultural activities and other societal needs, reported Mongabay India. India, along with at least 55 other countries, has an active cloud seeding programme. However, scientists still debate about the effectiveness of this technique. Delhi to bring odd-even Delhi environment minister Rai said on Monday that odd-even scheme will be implemented in the city between November 13 and 20. Under this, private vehicles with registration plates ending in odd numbers will be allowed to ply on odd dates, and those with even numbers on even dates. Meanwhile, the Supreme Court pulled up the governments of Punjab, Haryana and Rajasthan today (7 November) over worsening air quality in Delhi, directing these states to take measures to halt stubble burning by farmers immediately. According to NDTV, the apex court also dubbed the odd-even scheme to check pollution levels as “mere optics”. With inputs from agencies