Atmospheric abundance of HULIS during wintertime in Indo-Gangetic Plain: impact of biomass burning emissions

Light absorption and emissions inventory of humic-like substances from simulated rainforest biomass burning in Southeast Asia

“…However, direct comparisons of HULIS among different studies are hampered by the different methods used for isolating and quantifying HULIS (Nguyen et al, 2014). The HULIS-C/OC ratio (32% ± 11%) in the present study was higher than the ratios (27% ± 3.0% during the day and 20% ± 3.0% at night) in PM 10 in the Indo-Gangetic Plain (Kumar et al, 2018) but lower than that (36% ± 7.0%) in PM 2.5 from Weizhou Island (Zhou et al, 2018). Lin et al (2010a) observed that HULIS-C/OC ratios were much higher in BB-affected ambient samples (61% ± 16% and 62% ± 10% for suburban and urban samples, respectively) than in fresh BB samples, probably due to multiple pathways leading to secondary formation of HULIS as BB smoke ages in the atmosphere.…”

“…HULIS in atmospheric aerosols mainly contain aromatic and aliphatic carboxylic acids, organosulfates (OS), carbohydrates, and other components (Claeys et al, 2012), and they are mainly derived from BB and fossil fuel burning, soil weathering, vehicle emissions, and secondary sources including oligomerization or polymerization and aerosol aging through gaseous precursors from biological and anthropogenic sources through an atmospheric chemical process (Voliotis et al, 2017;Win et al, 2018). Among the sources listed above, BB is generally considered one of the largest (Kumar et al, 2018;Voliotis et al, 2017;Zhou et al, 2018). Kuang et al (2015) used positive matrix factorization analysis to determine 20%e28% of the HULIS-C (carbon mass of HULIS) derived from BB during winter in Guangzhou.…”

“…Furthermore, it was reported that BB has important effects in Southeast Asia, where there were significant organic carbon (OC) emissions (530e1100 Gg) in 2016 and where the emission factors (EFs) of pollutants are higher than those in North America, South America, and Africa (Cui et al, 2018 and references therein). Recent studies have investigated the chemical properties, abundance, light absorption properties, sources, and structural properties of HULIS in smoke particles emitted from BB in a laboratory combustion chamber and field campaigns (Kumar et al, 2018;Mo et al, 2018;Park and Yu, 2016;Sengupta et al, 2018;Song et al, 2018;Zhou et al, 2018). However, limited studies have been conducted on the EFs of HULIS in source emissions, such as BB, which are important for estimating emission inventories and climate impacts.…”

Chemical composition, optical properties, and oxidative potential of water- and methanol-soluble organic compounds emitted from the combustion of biomass materials and coal

“…Brown carbon (BrC) is an organic compound with strong light absorption at ultraviolet and short visible wavelengths and is abundant in ambient aerosols (Chen and Bond, 2010;Laskin et al, 2015;Alexander et al, 2008), rain, clouds, and fog water (Santos et al, 2009(Santos et al, , 2012Izhar et al, 2020). Due to its strong light absorption ability, BrC can affect the radiative balance of aerosol and photochemical reactions in the atmospheric environment (Andreae and Gelencser, 2006; N. K. Nozière et al, 2011).…”