Understanding the Influence of Post-Monsoon Crop-Residue Burning on Air Quality Over Rajasthan

Crop residue burning (CRB) has been a serious issue since 1986 in northwestern and northern India due to health threats and weather impacts. This study utilizes satellite and ground based data to assess the variations in the crop harvesting and burning periods, including their effects on the atmospheric conditions and air quality of Rajasthan during post-monsoon periods of 2002-2021. The normalized difference vegetation index (NDVI) values are found to show a shift (low values) from October to November until recent years. The increased fire counts in November indicate the change in harvesting and burning time. The crop residue burning in Punjab and Haryana is likely to influence the air quality of adjacent parts, as inferred from the higher AOD and AE values over source regions, leading to a rise in AOD and AE over Rajasthan in recent years. The higher AOD values during post-monsoon months are shown to be associated with high dust loading and the presence of biomass-burning aerosol. Pronounced changes are also observed in methane (CH4), Carbon monoxide (CO), Total Column Ozone (TCO), and Total column water (TCW) during post-monsoon. The HYSPILT trajectories show the airmass transport from the source regions of Punjab and Haryana towards Rajasthan, affecting the air quality to cause adverse impacts on human health and climate.