A recent study conducted by researchers at the Indian Institute of Tropical Meteorology (IITM) in Pune has raised alarm bells regarding the potential impact of increasing pollution levels on India’s monsoon season. The study, published in the Journal of Atmospheric and Solar-Terrestrial Physics, highlights significant findings about how aerosol concentrations, stemming largely from industrial emissions and other human activities, could lead to a reduction in rainfall from critical rain-bearing cloud systems during the monsoon onset.
The research focused on a prominent cloud cluster that formed over the Indian peninsula during the early summer monsoon of 2018. Using advanced numerical simulations, scientists analysed the development and rainfall patterns of these clouds under varying aerosol conditions. They observed a concerning trend: as aerosol levels escalated from clean to heavily polluted states, there was a substantial decline in the number of convective rain-producing elements within the cloud cluster. Specifically, the study noted a reduction of up to 50% in rainfall-producing convective elements under heavily polluted scenarios compared to cleaner conditions.
The study attributed this decline to the microphysical effects of aerosols, which induce the formation of smaller cloud droplets. While this initially increases total cloud water content through condensation, the smaller droplets are less effective in producing heavy rainfall. Moreover, dry mid-level atmospheric conditions further hampered cloud growth and rainfall intensity, exacerbating the overall reduction in monsoon precipitation.
Researchers emphasized that unchecked pollution levels, driven by industrial activities, vehicular emissions, and other sources, pose a significant threat to India’s monsoon-dependent agricultural economy and water resources. The findings underscore the urgent need for stringent environmental regulations and mitigation strategies to curb aerosol emissions and preserve the integrity of monsoon rainfall patterns.
As India grapples with escalating environmental challenges, including pollution-induced impacts on weather systems, the IITM study serves as a critical reminder of the intricate link between human activities and natural phenomena like the monsoon. Addressing these issues requires concerted efforts from policymakers, industries, and communities to mitigate pollution and safeguard the sustainability of India’s vital monsoon season.
