Detailed Characterization of Fine Aerosols from Crop Residue Burning of Major Indian Crops: Implications for Atmospheric Chemistry and Climate
ROSHAN KUMAR SINGH, Indra Mohan Nigam, Rowshon Afroz, Shakiba Talebian, Seema Prajapati, Kerry Chen, Antonio Mirante, Jason S. Olfert, Tarun Gupta, Ran Zhao, Indian Institute of Technology Kanpur
Abstract Number: 501
Working Group: Chemicals of Emerging Concern in Indoor and Outdoor Aerosol: Sources, Vectors, Reactivity, and Impacts
Abstract
Crop residue burning is a major seasonal source of air pollution in India, particularly over the Indo-Gangetic Plain, where agricultural intensity is high. While India cultivates a wide range of crops, over 90% of surplus residue subjected to open burning comes from wheat, rice, corn, millets, and sugarcane. Despite decades of research, a detailed physicochemical characterization of aerosols emitted from these Indian specific crop residues under controlled conditions remains limited. This study aims to fill that gap through a comprehensive laboratory analysis of fine particulate matter (PM2.5) emissions from the combustion of these five key residues. PM2.5 was measured gravimetrically using a dual-filter setup (quartz and Teflon) to capture both particulate and semi-volatile components. Emission factors of PM2.5 ranged from 6.8 to 16.4 g/kg, depending on crop type. Particle number concentrations were monitored using a scanning electrical mobility spectrometer, while chemical composition was assessed via analysis of elemental carbon, organic carbon, water-soluble organic carbon, water-soluble nitrogen, inorganic ions, and trace metals. Optical properties of carbonaceous aerosols were evaluated for both polar and non-polar fractions, shedding light on their light absorption and scattering behaviour. These insights are crucial for understanding the direct radiative forcing effects of such emissions and their role in short-lived climate forcers like brown carbon. Furthermore, this study contributes to improving emission inventories and advancing atmospheric chemistry models by offering detailed speciation data and aerosol characterization. Ultimately, this research enhances our understanding of crop-specific aerosol properties, informs climate impact assessments, and provides a critical dataset for policymakers working toward emission mitigation and sustainable agricultural practices in India and other developing nations.