A multi-year evolution of aerosol chemistry impacting visibility and haze formation over an Eastern Asia megacity, Shanghai

Lin, Yanfen; Huang, Kan; Zhuang, Guoshun; Fu, Joshua S.; Wang, Qiongzhen; Liu, Tingna; Deng, Congrui; Fu, Qingyan

doi:10.1016/j.atmosenv.2014.04.007

Cited by 73 publications

(29 citation statements)

References 32 publications

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“…The entire sampling period was divided into three categories based on the daily average visibility values: clear days (≥ 10 km, RH < 90 %), light haze days (5-10 km, RH < 90 %), and heavy haze days (≤ 5 km, RH < 90 %) Lin et al, 2014). As shown in Table 1, there were 11 heavy haze days, 8 light haze days, and 12 clear days during the 31 sampling days (nonprecipitation days).…”

Section: The Levels and Variation Characteristics Of Nmhcs During Thementioning

confidence: 99%

The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

Liu

et al. 2017

Atmos. Chem. Phys.

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Abstract. Atmospheric non-methane hydrocarbon compounds (NMHCs) were measured at a sampling site in Beijing city from 15 December 2015 to 14 January 2016 to recognize their pollution levels, variation characteristics, and sources. We quantified 53 NMHCs, and the proportions of alkanes, alkenes, acetylene, and aromatics to the total NMHCs were 49. 8-55.8, 21.5-24.7, 13.5-15.9, and 9.3-10.7 %, respectively. The variation trends in the NMHC concentrations were basically identical and exhibited remarkable fluctuation, which was mainly ascribed to the variation in meteorological conditions, especially wind speed. The diurnal variations in NMHCs on clear days exhibited two peaks during the morning and evening rush hours, whereas the rush hours' peaks diminished or even disappeared on the haze days, implying that the relative contribution of the vehicular emissions to atmospheric NMHCs depended on the pollution status. Two evident peaks of the propane / propene ratios appeared in the early morning before sun rise and at noontime on clear days, whereas only one peak occurred in the afternoon during the haze days, which were attributed to the relatively fast reactions of propene with OH, NO 3 , and O 3 . Based on the chemical kinetic equations, the daytime OH concentrations were calculated to be in the range of 3.47 × 10 5 -1.04 × 10 6 molecules cm −3 on clear days and 6.42×10 5 -2.35×10 6 molecules cm −3 on haze days. The nighttime NO 3 concentrations were calculated to be in the range of 2.82 × 10 9 -4.86 × 10 9 molecules cm −3 on clear days. The correlation coefficients of typical hydrocarbon pairs (benzene / toluene, o-xylene / m,p-xylene, isopentane / n-pentane, etc.) revealed that vehicular emissions and coal combustion were important sources for atmospheric NMHCs in Beijing during the wintertime. Five major emission sources for atmospheric NMHCs in Beijing during the wintertime were further identified by positive matrix factorization (PMF), including gasoline-related emissions (gasoline exhaust and evaporation), coal combustion, diesel exhaust, acetylene-related emissions, and consumer and household products. Coal combustion (probably domestic coal combustion) was found to make the greatest contribution (29.6-33.4 %) to atmospheric NMHCs during haze days.

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Section: The Levels and Variation Characteristics Of Nmhcs During Thementioning

confidence: 99%

The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

Liu

et al. 2017

Atmos. Chem. Phys.

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“…The IMPROVE algorithm is a concise way to link b ext with the major chemical components of particles, and therefore has been broadly used in previous studies to reconstruct the chemical budget of b ext (Hand and Malm, 2006;Malm and Hand, 2007;Yang et al, 2007;Jung et al, 2009;Cao et al, 2012;Lin et al, 2014;Tao et al, 2014aTao et al, , 2014b. However, the mass scattering/absorbing efficiency (MSE/MAE) and hygroscopic growth factor (f(RH)) set in the IMPROVE algorithm is only an approximation and simplification, and its extensive use in other sites, particularly ones in heavily polluted area, is always under question.…”

Section: Introductionmentioning

confidence: 99%

Changes in visibility with PM2.5 composition and relative humidity at a background site in the Pearl River Delta region

Wang

et al. 2016

Journal of Environmental Sciences

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“…In this study, days when PM 1.0 concentrations were b 100 μg m −3 and visibility (Lin et al, 2014) was N10 km were defined as normal days, and days when PM 1.0 concentrations were N100 μg m − 3 and visibility was b10 km were classified as haze days. Three normal day samples, labeled as samples A, B and C, were collected.…”

Section: Sample Collectionmentioning

confidence: 99%

Particle size distributions and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air during haze days and normal days

Zhang

Zheng

Liang

et al. 2016

Science of The Total Environment

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• PCDD/F particle size distributions on haze days and normal days were determined.• Higher concentrations of airborne PCDD/Fs were detected during all haze days.• 95% of PCDD/Fs were absorbed in the d ae b 2.5 μm particles on haze days.• Harner-Bidleman model predicted the particulate fractions of PCDD/F congeners well. G R A P H I C A L A B S T R A C TThe following figure is presented as the graphical abstract.a b s t r a c t a r t i c l e i n f o Little information is available on the distributions of airborne polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during haze days. In this study, PCDD/F concentrations, particle size distributions, and gas-particle partitioning in a Beijing suburban area during haze days and normal days were investigated. High PCDD/F concentrations, 3979-74,702 fg m −3 (173-3885 fg I-TEQ m −3), were found during haze days and~98% of the PCDD/Fs were associated with particles. Most PCDD/F congeners (N 90%) were associated with particles. PCDD/ F concentrations increased as particle sizes decreased and 95% of the particle-bound PCDD/Fs were associated with inhalable fine particles with aerodynamic diameters b 2.5 μm. PCDD/Fs were mainly absorbed in the particles and the Harner-Bidleman model predicted the particulate fractions of the PCDD/F congeners in the air samples well. The investigated PCDD/F concentrations and particle-bound distributions were different during normal days than during haze days. Temporal airborne PCDD/F trends in a suburban area during haze conditions could support better understanding of the exposure risk posed by toxic PCDD/Fs associated with fine particles.

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A multi-year evolution of aerosol chemistry impacting visibility and haze formation over an Eastern Asia megacity, Shanghai

Cited by 73 publications

References 32 publications

The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

The levels, variation characteristics, and sources of atmospheric non-methane hydrocarbon compounds during wintertime in Beijing, China

Changes in visibility with PM2.5 composition and relative humidity at a background site in the Pearl River Delta region

Particle size distributions and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans in ambient air during haze days and normal days

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