Delhi’s Cloud Seeding Trials Fail to Trigger Artificial Rain

Delhi’s much-anticipated cloud seeding exercise aimed at producing artificial rain to counter air pollution did not achieve the desired outcome. Conducted over key parts of the capital, the experiment involved aircraft dispersing salt-based and silver iodide flares into moisture-bearing clouds. However, the limited humidity levels and unfavourable atmospheric conditions led to minimal precipitation despite two attempts.

Purpose Behind the Cloud Seeding Initiative

The initiative was part of Delhi’s broader anti-pollution strategy, introduced as air quality dipped into the ‘severe’ category. Authorities had planned up to five trials to induce artificial rainfall capable of washing away suspended particulate matter. A specially fitted Cessna aircraft was used for the experiment, focusing on regions such as Khekra, Burari, North Karol Bagh and Mayur Vihar.

Scientific Factors Limiting Success

The primary reason for the unsuccessful trials was the inadequate moisture content in the clouds, measured at around 10–15 per cent—insufficient for rain formation. Although clouds were visible, they lacked the vertical development and liquid water concentration needed for the flares to catalyse rainfall. The seeding agents—each weighing between two and 2.5 kilograms—were deployed correctly, yet the atmospheric profile was not conducive to droplet formation.

Impact on Air Quality Parameters

Even though the trials failed to trigger measurable rain over Delhi, minor reductions in pollution levels were recorded in some locations. PM2.5 and PM10 concentrations showed a marginal dip immediately after seeding. Readings from Mayur Vihar, Karol Bagh and Burari indicated decreases from 221 to 207 for PM2.5 and from 207 to 177 for PM10. Short rainfall traces of 0.1 mm and 0.2 mm were reported in Noida and Greater Noida, respectively, suggesting limited localised effects.

Exam Oriented Facts

• Cloud seeding involves dispersing silver iodide or salt particles to stimulate condensation and precipitation.
• Delhi’s operation used a Cessna aircraft flying from Kanpur and Meerut, covering multiple urban sectors.
• Moisture levels below 30 per cent significantly reduce the probability of successful rainfall.
• It marked India’s first large-scale cloud seeding effort aimed at controlling urban air pollution.

Future Prospects for Artificial Rain Projects

The limited success of Delhi’s trial highlights the dependence of cloud seeding on precise meteorological conditions. Experts suggest that future attempts should be scheduled only when moisture levels, temperature gradients and cloud types are favourable. While artificial rain can temporarily reduce airborne pollutants, it cannot replace long-term solutions addressing emissions, stubble burning and vehicular pollution that continue to degrade Delhi’s air quality.