Snow cover dynamics in high-altitude Himalayan regions are critical for regional hydrology, climate regulation, and ecosystem balance. However, recent trends indicate accelerated snow ablation, driven by rising temperatures and increased atmospheric aerosol loading. This study examines the interplay between snow cover ablation and aerosol optical depth (AOD) in the Mago region of Arunachal Pradesh, an ecologically sensitive area experiencing significant cryospheric transformations.
To quantify interannual fluctuations in snow accumulation and ablation, we utilized MODIS-derived snow cover data, which enabled the assessment of seasonal and long-term variability. Concurrently, aerosol loadings were analyzed using MERRA-2 reanalysis data, allowing for a detailed evaluation of AOD and its specific components, including dust, black carbon, and other anthropogenic pollutants. Our findings indicate persistently high AOD values in the region, correlating with enhanced rates of snow ablation. Notably, for the years when ablation rates were significantly higher, AOD values were also observed to be elevated, suggesting a strong link between aerosol deposition and snowmelt acceleration. Among the aerosols, black carbon and fine particulate matter exhibit a pronounced influence on snowmelt processes. These light-absorbing particles, when deposited on the snowpack, reduce surface albedo, thereby increasing the absorption of solar radiation. This positive radiative forcing effect contributes to localized surface warming, leading to a decrease in snow persistence and an increase in meltwater runoff.
The results of this study underscore the critical role of atmospheric pollutants in modulating the energy balance of snow-covered surfaces. Given the reliance of downstream communities on glacial and snow-fed hydrological systems, understanding these interactions is essential for improving predictive models of snowmelt-driven discharge, assessing water resource sustainability, and developing mitigation strategies for cryospheric degradation. Furthermore, this research highlights the necessity of integrating aerosol-climate interactions into regional climate adaptation frameworks to mitigate the cascading effects of enhanced snowmelt on water security and disaster risk management in the Eastern Himalayas.