Cloud Seeding

Context

The Delhi Government has decided to postpone its planned cloud seeding trial for artificial rain after receiving scientific recommendations from the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM), Pune. The decision was based on the assessment that prevailing monsoon cloud patterns were not conducive to effective seeding operations, which require specific atmospheric and cloud conditions to yield optimal results.

What is Cloud Seeding?

Cloud seeding is a weather modification technique that involves dispersing substances into clouds to encourage precipitation.
Commonly used agents include:
Silver iodide (AgI)
Potassium iodide (KI)
Dry ice (solid CO?)
These substances act as nuclei for condensation, enhancing the ability of clouds to produce rain.

Purpose of Cloud Seeding in Delhi

Aimed at combating air pollution by:
Increasing rainfall to settle particulate matter (PM2.5 and PM10) in the air.
Improving air quality index (AQI) in the National Capital Region (NCR).
Coordinated by IIT Kanpur, involving 13 departments and clearances from the Directorate General of Civil Aviation (DGCA).

Key Institutional Stakeholders

India Meteorological Department (IMD) – Forecasting cloud structures and precipitation potential.
Indian Institute of Tropical Meteorology (IITM), Pune – Atmospheric modelling and advisories on seeding viability.
IIT Kanpur – Scientific execution and cloud microphysics modelling.
DGCA – Aviation safety clearance for aircraft-based cloud seeding.

Scientific Conditions for Successful Cloud Seeding

Cloud seeding is effective only when pre-existing clouds have sufficient moisture and vertical development.
Cumulus clouds with adequate liquid water content are ideal.
Monsoon clouds, due to high variability and saturated conditions, may not always respond to seeding agents.