气候变化领域集成服务门户(CCPortal): Significant seasonal changes in optical properties of brown carbon in the midlatitude atmosphere

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DOI	10.5194/acp-20-2709-2020
	Significant seasonal changes in optical properties of brown carbon in the midlatitude atmosphere
	Han H.; Kim G.; Seo H.; Shin K.-H.; Lee D.-H.
发表日期	2020
ISSN	16807316
起始页码	2709
结束页码	2718
卷号	20 期号:5
英文摘要	Atmospheric brown carbon (BrC) plays significant roles in the light absorption and photochemistry of the atmosphere. Although the sources and occurrences of BrC have been studied extensively, its removal processes and optical characteristics in the atmosphere have been poorly understood. In this study, we examined the seasonal changes in sources and sinks of BrC and water-soluble organic carbon (WSOC) in the atmosphere of Seoul, South Korea. Our results showed that the concentrations of BrC and WSOC decreased by approximately 80% and 30%, respectively, from the cold season (October-January) to the warm season (June-September). Excitation-emission matrix (EEM) spectra showed that the humic-like substance (HULIS) was the dominant fraction of BrC as the other components were not measurable. The air mass back trajectories of fire burning practices and the variations in non-crustal potassium (K) and vanadium (V) contents in the water-soluble aerosols during all seasons showed no measurable decrease in input of biomass-burning sources in summer. However, there was a significant shift in photo-resistivity of light-absorbing organic aerosols in the summer, indicating larger removals of ultraviolet (UV) degradable BrC. This trend is supported by laboratory UV radiation experiments on the optical property changes of BrC and WSOC in aerosol samples. Thus, our results suggest that the photodegradation has dominant roles in controlling the quantity and quality of light-absorbing organic aerosols in the different seasons in the midlatitude atmosphere. © 2020 Authors.
关键词	adsorption aerosol atmospheric chemistry brown carbon optical property photochemistry seasonal variation source apportionment Seoul [Seoul (ADS)]Seoul [South Korea]South Korea
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132189
推荐引用方式 GB/T 7714	Han H.,Kim G.,Seo H.,et al. Significant seasonal changes in optical properties of brown carbon in the midlatitude atmosphere[J]. Atmospheric Chemistry and Physics,2020,20(5).
APA	Han H.,Kim G.,Seo H.,Shin K.-H.,&Lee D.-H..(2020).Significant seasonal changes in optical properties of brown carbon in the midlatitude atmosphere.,20(5).
MLA	Han H.,et al."Significant seasonal changes in optical properties of brown carbon in the midlatitude atmosphere".20.5(2020).