Delhi cloud seeding trials yield little rain, air quality poor

Delhi authorities carried out cloud seeding trials on October 28 in an effort to induce artificial rain and relieve severe post‑Diwali smog, but the operations did not produce widespread rainfall and the city’s air quality remained poor to very poor in the days that followed. Aircraft from the Indian Institute of Technology Kanpur released silver iodide and salt‑based flares over parts of north and east Delhi, including Burari, Karol Bagh and Mayur Vihar, in sorties that officials said were intended to trigger rain within 15 minutes to four hours.

The Central Pollution Control Board reported citywide Air Quality Index readings repeatedly in the very poor range through the week, with several monitoring stations in the severe range. Anand Vihar, Vivek Vihar and Wazirpur were among locations recording the highest AQI values, above 400 at times. The India Meteorological Department said weak winds, fog and a low ventilation index trapped pollutants close to the ground, worsening exposure.

IIT Kanpur and its director said the trials were constrained by low cloud moisture, typically around 10 to 20 percent, well below the 50 percent or higher commonly considered necessary for effective...