Brownness of Organics in Anthropogenic Biomass Burning Aerosols over South Asia

• DOI: 10.5194/egusphere-2024-1313
• Publication Date: 2024-05-23T13:16:25Z
• Authors: Chimurkar Navinya; Taveen Singh Kapoor; Gupta Anurag; Chandra Venkataraman; Harish C. Phuleria; Rajan K. Chakrabarty
• Keywords: Chemistry; Physics; QC1-999; QD1-999; 01 natural sciences; 0105 earth and related environmental sciences

Abstract. In South Asia, biomass is burned for energy and waste disposal, producing brown carbon (BrC) aerosols whose climatic impacts are highly uncertain. To assess these impacts, a real-world understanding of BrC’s physio-optical properties essential. For this region, the order-of-magnitude variability in spectral refractive index as function particle volatility distribution poorly understood. This leads to oversimplified model parameterization subsequent underestimation regional radiative forcing. Here we used field-collected aerosol samples from major anthropogenic activities examine methanol-soluble BrC optical properties. We show strong relation between absorption strength, wavelength dependence, thermo-optical fractions carbonaceous aerosols. Our observations strongly absorbing near Himalayan foothills that may accelerate glacier melt, further highlighting limitations climate models where variable not considered. These findings provide crucial inputs refining developing effective strategies mitigate BrC.