Context:
Researchers from IIT Kanpur conducted cloud seeding operations over Delhi to induce artificial rain (October 28), despite IMD indicating insufficient clouds. The attempt failed twice.
Key Highlights:
Cloud Seeding Attempt Details
- IIT Kanpur used a Cessna aircraft with 10 kg mixture of
- Silver iodide (20%)
- Common salt & rock salt (80%)
- Objective: improve Delhi’s air pollution when AQI was severe / poor
- IMD + IITM Pune shared inputs → warned: not enough cloud moisture (<15%)
- IITM/IMD did NOT recommend go-ahead
Science Behind Cloud Seeding
- Cloud seeding = spraying chemical aerosols into clouds → induce condensation → rainfall
- Works only when “warm clouds” (i.e., moisture carrying) exist
- If clouds have vapour but insufficient water → no rain outcome
- India-based field trials historically inconclusive
Global Context
- China / UAE use cloud seeding widely
- India → experimental since 1972 (Solapur experiment = mixed results)
Cost Aspect
- Each flight sortie ≈ ₹15 lakh
- Delhi attempt → both sorties failed to deliver rain
Relevant Prelims Points:
- IITM-CAIPEX (Cloud Aerosol Interaction and Precipitation Enhancement Experiment) = India’s largest controlled cloud seeding experiment
- Cloud seeding works best for warm clouds (>18–20°C cloud top) + sufficient liquid water content
Relevant Mains Points:
- Artificial rain is not a substitute for long-term pollution control
- Appeals high in public imagination but science shows uncertain success probabilities
Way Forward:
- Indian cloud seeding needs better in-situ cloud profiling + LIDAR based moisture mapping before flight decisions
Possible Mains Question:
Do artificial rain technologies offer a viable solution for India’s pollution crises? Discuss with reference to recent cloud seeding attempts.