Long-Emission-Wavelength Humic-Like Component (L-HULIS) as a Secondary Source Tracer of Brown Carbon in the Atmosphere

doi:10.1029/2023JD040144

	Long-Emission-Wavelength Humic-Like Component (L-HULIS) as a Secondary Source Tracer of Brown Carbon in the Atmosphere
	Tang, Jiao 1,2; Xu, Buqing 1,2; Zhao, Shizhen 1,2; Li, Jun 1,2; Tian, Lele 1,2; Geng, Xiaofei 1,2; Jiang, Hongxing 3; Mo, Yangzhi 1,2; Zhong, Guangcai 1,2; Jiang, Bin 1,2; Chen, Yingjun 3; Tang, Jianhui4 ; Zhang, Gan 1,2
发表期刊	JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
ISSN	2169-897X
	2024-03-16
卷号	129 期号:5 页码:18
关键词	aerosols secondary brown carbon fluorescence spectroscopy secondary organic aerosol tracers non-fossil secondary source
DOI	10.1029/2023JD040144
通讯作者	Li, Jun([email protected]) ; Zhang, Gan([email protected])
英文摘要	The optical properties of secondary brown carbon (BrC) aerosols are poorly understood, hampering quantitative assessments of their impact. We propose a new method for estimating secondary source of BrC using excitation-emission matrix (EEM) fluorescence spectroscopy, combined with parallel factor analysis (PARAFAC) and partial least squares regression (PLSR). Experiments were conducted on a collection of PM2.5 samples from urban areas in five Chinese cities during winter and summer. The humic-like component with long-emission wavelengths (L-HULIS) was identified as a secondary source tracer of BrC. This was confirmed by correlating PARAFAC components with secondary organic aerosol tracers and molecular oxidation indices obtained from Fourier transform ion cyclotron resonance mass spectrometry analysis. Using L-HULIS as a secondary tracer of BrC, it was determined that the contribution of secondary sources to water-soluble BrC (WS-BrC) in source emission samples is significantly smaller than in PM2.5 from five Chinese cities, supporting our method. In the five cities, secondary source derived via L-HULIS contributes a dominant potion (80% +/- 3.5%) of WS-BrC at 365 nm during the summer, which is approximately twice as high as during the winter (45% +/- 4.9%). Radiocarbon isotope (14C) analysis provides additional constraints to the sources of L-HULIS-derived secondary WS-BrC in urban PM2.5, suggesting that aged biomass burning is the dominant contributor to secondary WS-BrC in winter, and biogenic emission is dominant during summer. This study is the first report on identification of secondary sources of BrC using the fluorescence technique. It demonstrates the potential of this method in characterizing non-fossil source secondary BrC in the atmosphere. Brown carbon (BrC) originates from primary combustion emissions and secondary formation, with large source-dependent uncertainties of radiative forcing. Direct measurements to separate the primary and secondary BrC are challenging due to the chemical complexity. Recent online studies have shown that excitation-emission matrix fluorescence spectroscopy coupled with parallel factor (PARAFAC) analysis identified some fluorescent components that may be linked to secondary sources. However, there is a knowledge gap on whether PARAFAC components correlate closely with atmospheric secondary chemical components, particularly biogenic and anthropogenic secondary organic aerosol, as their precursors can also form secondary BrC chromophores. We established the correlations between PARAFAC components and secondary organic aerosol tracers and compound oxidations to identify the long-emission-wavelength humic-like component as a secondary source tracer of BrC. Then, we estimated non-fossil source secondary BrC in urban aerosols during the winter and summer. Our studies provide references for quantifying secondary sources of BrC in the atmosphere. A fluorescence-based method was developed to investigate secondary sources of water-soluble brown carbon in five cities in China The contribution of secondary sources to water-soluble brown carbon in the summer is approximately twice as high as during the winter This secondary water-soluble brown carbon was more associated with aging biomass burning in winter and biogenic emissions in summer
资助机构	National Natural Science Foundation of China ; Alliance of International Science Organizations ; Guangdong Basic and Applied Basic Research Foundation
收录类别	SCI
语种	英语
关键词[WOS]	LIGHT-ABSORPTION PROPERTIES ; DISSOLVED ORGANIC-MATTER ; BIOMASS-BURNING AEROSOL ; OPTICAL-PROPERTIES ; MOLECULAR COMPOSITIONS ; MATRIX SPECTROSCOPY ; OXIDATION-STATE ; BLACK CARBON ; FLUORESCENCE ; WATER
研究领域[WOS]	Meteorology & Atmospheric Sciences
WOS记录号	WOS:001176094700001
引用统计
文献类型	期刊论文
条目标识符	http://ir.yic.ac.cn/handle/133337/36173
专题	中国科学院海岸带环境过程与生态修复重点实验室中国科学院海岸带环境过程与生态修复重点实验室_海岸带环境过程实验室
通讯作者	Li, Jun; Zhang, Gan
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou, Peoples R China 2.Chinese Acad Sci, Guangzhou Inst Geochem, Guangdong Prov Key Lab Environm Protect & Resource, Guangdong Hong Kong Macao Joint Lab Environm Pollu, Guangzhou, Peoples R China 3.Fudan Univ, Dept Environm Sci & Engn, Shanghai Key Lab Atmospher Particle Pollut & Preve, Shanghai, Peoples R China 4.Chinese Acad Sci, Yantai Inst Coastal Zone Res, Key Lab Coastal Environm Proc & Ecol Remediat, Yantai, Peoples R China
推荐引用方式 GB/T 7714	Tang, Jiao,Xu, Buqing,Zhao, Shizhen,et al. Long-Emission-Wavelength Humic-Like Component (L-HULIS) as a Secondary Source Tracer of Brown Carbon in the Atmosphere[J]. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES,2024,129(5):18.
APA	Tang, Jiao.,Xu, Buqing.,Zhao, Shizhen.,Li, Jun.,Tian, Lele.,...&Zhang, Gan.(2024).Long-Emission-Wavelength Humic-Like Component (L-HULIS) as a Secondary Source Tracer of Brown Carbon in the Atmosphere.JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES,129(5),18.
MLA	Tang, Jiao,et al."Long-Emission-Wavelength Humic-Like Component (L-HULIS) as a Secondary Source Tracer of Brown Carbon in the Atmosphere".JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 129.5(2024):18.