Cloud Seeding Not a Reliable Strategy for Managing Winter Air Pollution in Delhi

A study conducted by the Centre for Atmospheric Sciences at the Indian Institute of Technology Delhi (IIT Delhi) has concluded that cloud seeding cannot be a primary or reliable strategy for managing winter air pollution in Delhi. The researchers found that the capital's climatic conditions are unsuitable for cloud seeding, and it should be viewed as a potential high-cost, emergency short-term measure contingent on stringent forecasting criteria. The study also highlights that sustained emission reduction remains the most viable and necessary long-term solution to air pollution.

Key Takeaways:

• The IIT Delhi study found that Delhi's climatic conditions are not suitable for cloud seeding, making it an unreliable strategy for managing winter air pollution.
• The study suggests that cloud seeding is a high-cost, emergency short-term measure that should be used only in specific conditions, and not as a primary solution to air pollution.
• Sustained emission reduction from sources such as vehicular traffic, industrial activities, construction dust, agricultural biomass burning, and residential heating remains the most viable and necessary long-term solution to air pollution.
• The study also highlights the environmental and health concerns related to the use of seeding agents like AgI (silver iodide) and the high operational costs.
• Cloud seeding is not a reliable method for reducing air pollution in Delhi, as rain has minimal impact on pollutant concentrations, and pollutant levels typically recover to pre-event levels within 1-5 days.

Statistics:

• The study analyzed climatological data from 2011-2021 and found that Delhi's climatic conditions are not suitable for cloud seeding.
• The researchers identified that Western Disturbances (WDs) are the primary drivers of potential seeding conditions, but viable "windows of opportunity" are rare and confined to specific anomalous events.
• The study noted that even on days identified as potentially promising, a multi-criteria Moisture Suitability Index (MSI) indicates that they frequently lack the necessary combination of moisture depth, saturation, and atmospheric lift required for successful seeding.
• The analysis confirmed that heavy natural rainfall is highly effective in washing out PM2.5, PM10, and NOX, while light rain offers minimal impact on pollutant concentrations.

Sources:

• The Indian Express (P) Ltd, distributed by Contify.com
• IIT Delhi study, 'Can Cloud Seeding Help Tackle Delhi's Air Pollution?'