中国科学院重庆绿色智能技术研究院机构知识库

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	Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties
	Huang, Ru-Jin1; Yang, Lu1; Cao, Junji1; Chen, Yang2; Chen, Qi3; Li, Yongjie4; Duan, Jing1; Zhu, Chongshu1; Dai, Wenting1; Wang, Kai1,5
	2018-06-19
摘要	Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) was found to correlate strongly with both parent polycyclic aromatic hydrocarbons (parent-PAHs, 27 species) and their carbonyl oxygenated derivatives (carbonyl-OPAHs, 15 species) in all seasons (r(2) > 0.61). These measured parent-PAHs and carbonyl-OPAHs account for on average similar to 1.7% of the overall absorption of methanol-soluble BrC, about 5 times higher than their mass fraction in total organic carbon (OC, similar to 0.35%). The fractional solar absorption by BrC relative to element carbon (EC) in the ultraviolet range (300-400 nm) is significant during winter (42 +/- 18% for water-soluble BrC and 76 +/- 29% for methanol-soluble BrC), which may greatly affect the radiative balance and tropospheric photochemistry and therefore the climate and air quality.
DOI	10.1021/acs.est.8b02386
发表期刊	ENVIRONMENTAL SCIENCE & TECHNOLOGY
ISSN	0013-936X
卷号	52期号:12页码:6825-6833
收录类别	SCI
WOS记录号	WOS:000436018900013
语种	英语