Characterization of submicron particles by time-of-flight aerosol chemical speciation monitor (ToF-ACSM) during wintertime: aerosol composition, sources, and chemical processes in Guangzhou, China

doi:10.5194/acp-20-7595-2020

	Characterization of submicron particles by time-of-flight aerosol chemical speciation monitor (ToF-ACSM) during wintertime: aerosol composition, sources, and chemical processes in Guangzhou, China
	Guo, Junchen 8,9; Zhou, Shengzhen 7,8,9; Cai, Mingfu 8,9; Zhao, Jun 7,8,9; Song, Wei 6; Zhao, Weixiong 5; Hu, Weiwei 6; Sun, Yele 4; He, Yao 4; Yang, Chengqiang 5
刊名	ATMOSPHERIC CHEMISTRY AND PHYSICS
	2020-07-01
卷号	20
ISSN号	1680-7316
DOI	10.5194/acp-20-7595-2020
通讯作者	Zhou, Shengzhen(zhoushzh3@mail.sysu.edu.cn) ; Zhao, Jun(zhaojun23@mail.sysu.edu.cn)
英文摘要	Particulate matter (PM) pollution in China is an emerging environmental issue which policy makers and the public have increasingly paid attention to. In order to investigate the characteristics, sources, and chemical processes of PM pollution in Guangzhou, field measurements were conducted from 20 November 2017 to 5 January 2018, with a time-of-flight aerosol chemical speciation monitor (ToFACSM) and other collocated instruments. Mass concentrations of non-refractory submicron particulate matter (NR-PM1) measured by the ToF-ACSM correlated well with those of PM2.5 or PM1.1 measured by filter-based methods. The organic mass fraction increased from 45 % to 53 % when the air switched from non-pollution periods to pollution episodes (EPs), indicating significant roles of organic aerosols (OAs) during the whole study. Based on the mass spectra measured by the ToF-ACSM, positive matrix factorization (PMF) with the multilinear engine (ME-2) algorithm was performed to deconvolve OA into four factors, including hydrocarbon-like OA (HOA, 12 %), cooking OA (COA, 18 %), semi-volatile oxygenated OA (SVOOA, 30 %), and low-volatility oxygenated OA (LVOOA, 40 %). Furthermore, we found that SVOOA and nitrate were significantly contributed from local traffic emissions while sulfate and LVOOA were mostly attributed to regional pollutants. Comparisons between this work and other previous studies in China show that secondary organic aerosol (SOA) fraction in total OA increases spatially across China from the north to the south. Two distinctly opposite trends for NR-PM1 formation were observed during non-pollution periods and pollution EPs. The ratio of secondary PM (SPM = SVOOA + LVOOA + sulfate + nitrate + ammonium) to primary PM (PPM = HOA + COA + chloride), together with peroxy radicals RO2* and ozone, increased with increasing NR-PM1 concentration during non-pollution periods, while an opposite trend of these three quantities was observed during pollution EPs. Furthermore, oxidation degrees of both OA and SOA were investigated using the f(44)/f(43) space and the results show that at least two OOA factors are needed to cover a large range of f(44) and f(43) in Guangzhou. Comparisons between our results and other laboratory studies imply that volatile organic compounds (VOCs) from traffic emissions, in particular from diesel combustion and aromatic compounds, are the most likely SOA precursors in Guangzhou. Peroxy radical RO2* was used as a tracer for SOA formed through gas-phase oxidation. For non-pollution periods, SOA concentration was reasonably correlated with RO2* concentration during both daytime and nighttime, suggesting that gas-phase oxidation was primarily responsible for SOA formation. However, there was no correlation between SOA and RO2* in pollution EPs, suggesting a dramatically changed mechanism for SOA formation. This conclusion can also be supported by different features of SOA in a van Krevelen diagram between non-pollution periods and pollution EPs. Furthermore, for pollution EPs, when NR-PM1 mass concentration was divided into six segments, in each segment except for the lowest one SOA concentration was correlated moderately with RO2* concentration, suggesting that gas-phase oxidation still plays important roles in SOA formation. The intercepts of the above linear regressions, which likely correspond to the extent of other mechanisms (i.e., heterogeneous and multiphase reactions), increase with increasing NR-PM1 mass concentration. Our results suggest that while gas-phase oxidation contributes predominantly to SOA formation during non-pollution periods, other mechanisms such as heterogeneous and multiphase reactions play more important roles in SOA formation during pollution EPs than gas-phase oxidation.
资助项目	National Key Research and Development Program of China[2016YFC0202205] ; National Key Research and Development Program of China[2017YFC0210104] ; National Natural Science Foundation of China[41875152] ; National Natural Science Foundation of China[91644225] ; National Natural Science Foundation of China[21577177] ; Science and Technology Program of Guangdong Province (Science and Technology Innovation Platform Category)[2019B121201002] ; National Science Fund for Distinguished Young Scholars[4142502] ; National Natural Science Foundation as a key project[41530641] ; National Natural Science Foundation as a key project[41630422] ; 111 plan project of China[B17049] ; Scientific and Technological Innovation Team Project of Guangzhou Joint Research Center of Atmospheric Sciences, China Meteorological Administration[201704]
WOS关键词	SECONDARY ORGANIC AEROSOL ; FINE PARTICULATE MATTER ; MEXICO-CITY ATMOSPHERE ; PEARL RIVER DELTA ; MASS-SPECTROMETER ; COLLECTION EFFICIENCIES ; ELEMENTAL COMPOSITION ; SOURCE APPORTIONMENT ; OXIDATIVE CAPACITY ; INORGANIC AEROSOLS
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
语种	英语
出版者	COPERNICUS GESELLSCHAFT MBH
WOS记录号	WOS:000546061800001
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China ; Science and Technology Program of Guangdong Province (Science and Technology Innovation Platform Category) ; National Science Fund for Distinguished Young Scholars ; National Natural Science Foundation as a key project ; 111 plan project of China ; Scientific and Technological Innovation Team Project of Guangzhou Joint Research Center of Atmospheric Sciences, China Meteorological Administration
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/71160]
专题	中国科学院合肥物质科学研究院
通讯作者	Zhou, Shengzhen; Zhao, Jun
作者单位	1.Jinan Univ, Inst Environm & Climate Res, Guangzhou 511443, Peoples R China 2.Jinan Univ, Inst Technol Atmospher Environm Safety & Pollut C, Guangzhou 510632, Peoples R China 3.Minist Ecol & Environm, South China Inst Environm Sci, Guangzhou 510655, Peoples R China 4.Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & At, Beijing 100029, Peoples R China 5.Chinese Acad Sci, Anhui Inst Opt & Fine Mech, Lab Atmospher Physicochem, Hefei 230031, Peoples R China 6.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Peoples R China 7.Southern Marine Sci & Engn Guangdong Lab Zhuhai, Zhuhai 519082, Peoples R China 8.Sun Yat Sen Univ, Inst Earth Climate & Environm Syst, Guangzhou 510275, Peoples R China 9.Sun Yat Sen Univ, Sch Atmospher Sci, Guangdong Prov Key Lab Climate Change & Nat Disas, Guangzhou 510275, Peoples R China
推荐引用方式 GB/T 7714	Guo, Junchen,Zhou, Shengzhen,Cai, Mingfu,et al. Characterization of submicron particles by time-of-flight aerosol chemical speciation monitor (ToF-ACSM) during wintertime: aerosol composition, sources, and chemical processes in Guangzhou, China[J]. ATMOSPHERIC CHEMISTRY AND PHYSICS,2020,20.
APA	Guo, Junchen.,Zhou, Shengzhen.,Cai, Mingfu.,Zhao, Jun.,Song, Wei.,...&Wang, Xuemei.(2020).Characterization of submicron particles by time-of-flight aerosol chemical speciation monitor (ToF-ACSM) during wintertime: aerosol composition, sources, and chemical processes in Guangzhou, China.ATMOSPHERIC CHEMISTRY AND PHYSICS,20.
MLA	Guo, Junchen,et al."Characterization of submicron particles by time-of-flight aerosol chemical speciation monitor (ToF-ACSM) during wintertime: aerosol composition, sources, and chemical processes in Guangzhou, China".ATMOSPHERIC CHEMISTRY AND PHYSICS 20(2020).