New Delhi: The Delhi government’s proposed cloud seeding experiment, aimed at tackling severe post-Diwali air pollution, has faced multiple delays due to the absence of suitable clouds. Despite worsening air quality across Delhi-NCR and the implementation of GRAP Stage 2 restrictions, experts warn that conducting cloud seeding during the post-monsoon season may be ineffective.

Why the timing matters

Delhi signed an MoU with IIT-Kanpur in September to carry out cloud seeding using a Cessna 206H aircraft from Hindon Airbase at a cost of ₹3.5 crore. However, the India Meteorological Department classifies October to December as the post-monsoon season, a period marked by calm winds and dry conditions. Without the moisture-laden monsoon clouds needed for effective seeding, any attempt is unlikely to produce rain.

Officials from the Ministry of Earth Sciences (MoES) say the Delhi government may have been “misadvised” about the timing, as winter weather systems like western disturbances offer limited opportunities for cloud formation.

Lessons from past experiments

MoES has previously conducted the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) in southern India between 2009 and 2019. Results showed rainfall could increase by up to 46 per cent in some locations, but these experiments were carried out under favourable monsoon conditions.

Experts note that while cloud seeding can aid rainfall in specific catchment areas, suppress fog or hail, and support weather modification research, the current conditions over Delhi are not conducive to its success.