Exploring Aerosol Dynamics in Central Himalaya During North Indian Biomass Burning Event-2022

This study investigates the impact of winter biomass burning events in northern India during October-November, 2022 over the central Himalayas (CH). Continuous, high-resolution ground measurements of PM
2.5
from various CH sites confirmed the direct impact of these events. A comprehensive analysis using satellite and reanalysis datasets, including MODIS-derived Aerosol Optical Depth (AOD), VIIRS fire counts, along with MERRA-2-derived PM
2.5
components (BC, OC, SO4, SS, and Dust) and shortwave/longwave radiation, were employed. Fire-impacted periods were identified using VIIRS fire counts and PM
2.5
observations, revealing substantial enhancements in surface BC, OC, and SO
4
by approximately 180%, 160%, and 80%, respectively. Moreover, MODIS AOD exhibited significant enhancements (~0.8) over the Uttarakhand region. The study underscores biomass burning induced reduction in surface incoming shortwave radiation flux (-29 Wm
⁻²
) and an increase in surface absorbed longwave radiation (20 Wm
⁻²
). These alterations may influence short-wave absorption above clouds and potentially impact the glaciers in the winter.