In News:

With the national capital grappling with chronic air pollution every winter, the Delhi Government is exploring artificial rain (cloud seeding) as a potential mitigation strategy. In a recent high-level meeting chaired by Environment Minister Manjinder Singh Sirsa, experts and representatives from key institutions brainstormed the feasibility and logistics of implementing cloud seeding in Delhi's airspace.

What is Artificial Rain (Cloud Seeding)?

• Cloud seeding is a form of weather modification aimed at inducing rainfall.
• It involves spraying chemical agents such as silver iodide or salt particles into clouds to stimulate condensation and precipitation.
• Requires favourable meteorological conditions, especially adequate moisture and cloud density.
• Usually conducted using aircraft or ground-based dispersal systems.

Significance for Delhi:

• Rainfall helps settle airborne particulate matter (PM2.5 and PM10), thereby reducing pollution levels.
• Delhi’s air quality worsens in winter due to a combination of low wind speeds, crop residue burning, vehicular and industrial emissions, and construction dust.
• Artificial rain could serve as an emergency intervention to improve air quality during severe pollution episodes.

Key Highlights of the Meeting:

• Convened by Delhi Environment Department with participation from:
  • CPCB, DPCC
  • Ministry of Defence, MoEFCC
  • IIT-Kanpur, India Meteorological Department (IMD)
  • Directorate General of Civil Aviation (DGCA), AAI
• IIT-Kanpur scientists shared results from previous successful cloud seeding trials in Kanpur (2023), demonstrating its potential under ideal conditions.
• Past trials in 2018 also showed partial success, with rainfall occurring in 5 out of 6 attempts during pre-monsoon months.

Challenges Identified:

• Weather-dependence: Effectiveness relies heavily on cloud presence and moisture levels, which are limited in Delhi during winters.
• Airspace clearance and coordination among multiple agencies (civil aviation, defence).
• High costs and uncertain outcomes make it a supplementary, not primary, solution.

Complementary Measures Underway:

• Delhi’s 14-point action plan to curb dust pollution includes:
  • Anti-smog guns, covering construction sites, cleaning of construction vehicles, andregulated debris disposal.
• Exploring static ionisation systems as an alternative to cloud seeding for artificial precipitation.