Characteristics of aerosol size distributions and chemical compositions during wintertime pollution episodes in Beijing

被引:90
作者
Liu, Zirui [1 ]
Hu, Bo [1 ]
Zhang, Junke [1 ]
Yu, Yangchun [1 ]
Wang, Yuesi [1 ]
机构
[1] Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Atmospher Boundary Layer Phys & Atm, Beijing 100029, Peoples R China
基金
中国国家自然科学基金;
关键词
Particle number size distribution; Chemical composition; Secondary transformation; Evolution of pollution episode; PEARL RIVER-DELTA; HAZE-FOG EPISODES; AIR-POLLUTION; MIXING STATE; EVOLUTION PROCESSES; FORMATION MECHANISM; BACKGROUND SITE; EASTERN CHINA; PM2.5; ACIDITY; REGIONAL HAZE;
D O I
10.1016/j.atmosres.2015.08.013
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
To characterize the features of particle pollution, continuous measurements of partide number size distributions and chemical compositions were performed at an urban site in Beijing in January 2013. The particle number and volume concentration from 14 nm to 1000 nm were (37.4 +/- 153) x 10(3) cm(-3) and (85.2 +/- 65.6) mu m(3) cm(-3), respectively. N-Alt (Aitken mode) particles dominated the number concentration, whereas N-Acc (accumulation mode) particles dominated the volume concentration. Submicron particles were generally characterized by a high content of organics and SO42-, and a low level of NO3- and Cl-. Two types of pollution episodes were observed, characterized by the "explosive growth" (EXP) and "sustained growth" (SUS) of PM25. Fine particles greater than 100 nm dominated the volume concentration during the ends of these pollution episodes, shifting the maximum of the number size distribution from 60 nm to greater than 100 nm in a few hours (EXP) or a few days (SUS). Secondary transformation is the main reason for the pollution episodes; SO42-, NO3- and NH4+ (SNA) accounted for approximately 42% (EXP) and greater than 60% (SUS) of the N-Acc particle mass increase. The size distributions of particulate organics and SNA varied on timescales of hours to days, the characteristics of which changed from bimodal to unimodal during the evolution of haze episodes. The accumulation mode (peaking at approximately 500-700.nm) was dominated by organics that appeared to be internally mixed with nitrate or sulfate. The sulfate was most likely formed via heterogeneous reactions, because the SOR was constant under dry conditions (RH < 50%) and began to increase when RH > 50%, suggesting an important contribution from heterogeneous reactions with abundant aerosol water under wet conditions. Finally, the correlations between [NO3-]/[SO42-] and [NH4+][SO42-] suggest that the homogenous reaction between HNO3 and NH3 dominated the formation of nitrate under conditions of lower aerosol acidity. Therefore, controlling the precursors of SNA will effectively help to reduce the fine particulate pollution during winter in Beijing. (C) 2015 Elsevier B.V. All rights reserved.
引用
收藏
页码:1 / 12
页数:12
相关论文
共 65 条
[1]   Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City [J].
Adachi, K. ;
Buseck, P. R. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2008, 8 (21) :6469-6481
[2]   Characterization of urban and rural organic particulate in the lower Fraser valley using two aerodyne aerosol mass spectrometers [J].
Alfarra, MR ;
Coe, H ;
Allan, JD ;
Bower, KN ;
Boudries, H ;
Canagaratna, MR ;
Jimenez, JL ;
Jayne, JT ;
Garforth, AA ;
Li, SM ;
Worsnop, DR .
ATMOSPHERIC ENVIRONMENT, 2004, 38 (34) :5745-5758
[3]   Quantitative sampling using an Aerodyne aerosol mass spectrometer - 2. Measurements of fine particulate chemical composition in two U.K. cities [J].
Allan, JD ;
Alfarra, MR ;
Bower, KN ;
Williams, PI ;
Gallagher, MW ;
Jimenez, JL ;
McDonald, AG ;
Nemitz, E ;
Canagaratna, MR ;
Jayne, JT ;
Coe, H ;
Worsnop, DR .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2003, 108 (D3)
[4]   A modeling analysis of a heavy air pollution episode occurred in Beijing [J].
An, X. ;
Zhu, T. ;
Wang, Z. ;
Li, C. ;
Wang, Y. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2007, 7 (12) :3103-3114
[5]  
[Anonymous], 2006, ATMOS CHEM PHYS
[6]   An Enhanced Procedure for the Merging of Atmospheric Particle Size Distribution Data Measured Using Electrical Mobility and Time-of-Flight Analysers [J].
Beddows, David C. S. ;
Dall'osto, Manuel ;
Harrison, Roy M. .
AEROSOL SCIENCE AND TECHNOLOGY, 2010, 44 (11) :930-938
[7]   The mixing state of carbonaceous aerosol particles in northern and southern California measured during CARES and CalNex 2010 [J].
Cahill, J. F. ;
Suski, K. ;
Seinfeld, J. H. ;
Zaveri, R. A. ;
Prather, K. A. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2012, 12 (22) :10989-11002
[8]   Chase studies of particulate emissions from in-use New York City vehicles [J].
Canagaratna, MR ;
Jayne, JT ;
Ghertner, DA ;
Herndon, S ;
Shi, Q ;
Jimenez, JL ;
Silva, PJ ;
Williams, P ;
Lanni, T ;
Drewnick, F ;
Demerjian, KL ;
Kolb, CE ;
Worsnop, DR .
AEROSOL SCIENCE AND TECHNOLOGY, 2004, 38 (06) :555-573
[9]   Air pollution in mega cities in China [J].
Chan, Chak K. ;
Yao, Xiaohong .
ATMOSPHERIC ENVIRONMENT, 2008, 42 (01) :1-42
[10]   Size-resolved measurement of the mixing state of soot in the megacity Beijing, China: diurnal cycle, aging and parameterization [J].
Cheng, Y. F. ;
Su, H. ;
Rose, D. ;
Gunthe, S. S. ;
Berghof, M. ;
Wehner, B. ;
Achtert, P. ;
Nowak, A. ;
Takegawa, N. ;
Kondo, Y. ;
Shiraiwa, M. ;
Gong, Y. G. ;
Shao, M. ;
Hu, M. ;
Zhu, T. ;
Zhang, Y. H. ;
Carmichael, G. R. ;
Wiedensohler, A. ;
Andreae, M. O. ;
Poeschl, U. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2012, 12 (10) :4477-4491