A two-year study of carbonaceous aerosols in ambient PM2.5 at a regional background site for western Yangtze River Delta, China

Dong, Chen; Cui, Haiyan; Zhao, Yu; Yin, Lina; Lu, Yan; Wang, Qin’geng

doi:10.1016/j.atmosres.2016.09.004

Cited by 61 publications

(46 citation statements)

References 56 publications

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“…Taking all data (n = 28490) as a whole, hourly concentration levels of OC and EC range from 0.20 to 62.05 µg m −3 (average: 7.19 ± 4.98 µg m −3 ) and from 0.06 to 20.49 µg m −3 (average: 2.37 ± 1.87 µg m −3 ), respectively, contributing on average ∼ 20 (OC) and ∼ 5.0 % (EC) to the PM 2.5 mass between 2013 and 2014. The ratio of OC to EC throughout our study period is 3.70 ± 1.91, which is much high than a previous study performed in the Yangtze River Delta region (e.g., 2.36 in Nanjing city; Chen et al, 2017a). A much higher OC / EC ratio in our study indicates that secondary organic aerosol is more important in Shanghai, which will be extensively discussed in our next work regarding elucidating its sources and formation mechanism.…”

Section: Temporal Evolution Of Oc and Ec Mass Concentrations 321 Dacontrasting

confidence: 45%

“…Scatter plots of EC vs. CO in Fig. 9 confirms that on-road traffic is a significant source contributing to EC emissions in Shanghai (Chen et al, 2017a;Yang et al, 2005).…”

Section: Diurnal Variations and Weekend-weekday Comparisonsmentioning

confidence: 48%

“…Except for a slightly higher concentration of EC in the fall of 2012 due to the boost in intensive pollution episodes (indicated by a significantly higher value in P95 or 95th percentile; Table 1), higher concentrations of EC were observed in winter for other years, which could be caused by the stagnation of the atmosphere and the stronger influence of regional transport during wintertime (Chen et al, 2017a). However, it is worth noting that the concentration levels of EC in spring, summer, and fall were overall similar (Table 1), reflecting generally local-dominated EC Figure 5.…”

Section: Monthly and Seasonal Variationsmentioning

confidence: 99%

“…Burning of crop residues is also an important source of OC in China (Cheng et al, 2014;Hallquist et al, 2009;Zhang and Cao, 2015), while the burning activities are highly season dependent and mostly concentrated in fall (Chen et al, 2017b). Cold air masses prevail during winter and early spring, transporting high levels of pollutants (including OC and its precursors emitted from coal-based heating system) from northern China to the Yangtze River Delta region (Chen et al, 2017a). Scatter plots of OC and EC and their correlation coefficients are shown by season in Fig.…”

Section: Monthly and Seasonal Variationsmentioning

confidence: 99%

“…Nevertheless, biomass burning activities are mostly concentrated in the months of June and October, the periods of crop post-harvest. The second but more important reason could be the influence of anthropogenic activities (excluding prescribed biomass burning; Chen et al, 2017a). Indeed, the pollution belt overlaps the Yangtze River Economic Belt, one of China's most densely populated areas clustering with many cities (including big cities like Wuhan, Changsha, Nanchang, Hefei, Nanjing, and Suzhou), and numerous industrial complexes (including massive petrochemical, iron and steel, and chemical processing industry).…”

Section: Meteorological Effectsmentioning

confidence: 99%

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Assessment of carbonaceous aerosols in Shanghai, China – Part 1: long-term evolution, seasonal variations, and meteorological effects

et al. 2017

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Abstract. Carbonaceous aerosols are major chemical components of fine particulate matter (PM 2.5 ) with major impacts on air quality, climate change, and human health. Gateway to fast-rising China and home of over twenty million people, Shanghai throbs as the nation's largest mega city and the biggest industrial hub. From July 2010 to December 2014, hourly mass concentrations of ambient organic carbon (OC) and elemental carbon (EC) in the PM 2.5 fraction were quasi-continuously measured in Shanghai's urban center. The annual OC and EC concentrations (mean ±1σ ) in 2013 (8.9 ± 6.2 and 2.6 ± 2.1 µg m −3 , n = 5547) and 2014 (7.8 ± 4.6 and 2.1 ± 1.6 µg m −3 , n = 6914) were higher than those of 2011 (6.3 ± 4.2 and 2.4 ± 1.8 µg m −3 , n = 8039) and 2012 (5.7 ± 3.8 and 2.0 ± 1.6 µg m −3 , n = 4459). We integrated the results from historical field measurements (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) and satellite observations (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013), concluding that carbonaceous aerosol pollution in Shanghai has gradually reduced since 2006. In terms of monthly variations, average OC and EC concentrations ranged from 4.0 to 15.5 and from 1.4 to 4.7 µg m −3 , accounting for 13.2-24.6 and 3.9-6.6 % of the seasonal PM 2.5 mass (38.8-94.1 µg m −3 ), respectively. The concentrations of EC (2.4, 2.0, 2.2, and 3.0 µg m −3 in spring, summer, fall, and winter, respectively) showed little seasonal variation (except in winter) and weekend-weekday dependence, indicating EC is a relatively stable constituent of PM 2.5 in the Shanghai urban atmosphere. In contrast to OC (7.3, 6.8, 6.7, and 8.1 µg m −3 in spring, summer, fall, and winter, respectively), EC showed marked diurnal cycles and correlated strongly with CO across all seasons, confirming vehicular emissions as the dominant source of EC at the targeted site. Our data also reveal that both OC and EC showed concentration gradients as a function of wind direction (WD) and wind speed (WS), generally with higher values associated with winds from the southwest, west, and northwest. This was consistent with their higher potential as source areas, as determined by the potential source contribution function (PSCF) analysis. A common high-potential source area, located along the middle and lower reaches of the Yangtze River instead of northern China, was pinpointed during all seasons. These results demonstrate that the measured carbonaceous aerosolsPublished by Copernicus Publications on behalf of the European Geosciences Union.

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Section: Temporal Evolution Of Oc and Ec Mass Concentrations 321 Dacontrasting

confidence: 45%

“…Scatter plots of EC vs. CO in Fig. 9 confirms that on-road traffic is a significant source contributing to EC emissions in Shanghai (Chen et al, 2017a;Yang et al, 2005).…”

Section: Diurnal Variations and Weekend-weekday Comparisonsmentioning

confidence: 48%

Section: Monthly and Seasonal Variationsmentioning

confidence: 99%