Seasonal variations and source identification of selected organic acids associated with PM10 in the coastal area of Southeastern China

Wu, Shi; Schwab, James J.; Liu, Bilian; Li, Tsung-Chang; Yuan, Chung-Shin

doi:10.1016/j.atmosres.2014.11.014

Cited by 35 publications

(26 citation statements)

References 64 publications

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“…2(a), 2(c), 2(e) and 2(g)) helped PM 2.5 to disperse and resulted in lower PM 2.5 concentrations. Similar seasonal trends have also been observed for sulfur dioxide (SO 2 ), nitrogen dioxides (NO 2 ), nitric oxide (NO), PM 10 and associated polycyclic aromatic hydrocarbons and organic acids in this area (Hsu et al, 2010;Wu et al, 2012;Xu et al, 2012;Zhang et al, 2012;Wu et al, 2015). Significant associations were also found between PM 2.5 and some meteorological parameters such as wind speed, ambient temperature, pressure and mixing coefficient as well as its precursors such as SO 2 and NO x at XM and FZ sites (p < 0.001) (Tables S1 and S2).…”

Section: Chemical Analysismentioning

confidence: 50%

Two-Years PM2.5 Observations at Four Urban Sites along the Coast of Southeastern China

Schwab

Yang

et al. 2015

Aerosol Air Qual. Res.

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PM 2.5 samples from four coastal urban sites (Fuzhou, Putian, Quanzhou, and Xiamen) in Southeastern China were collected to analyze their major chemical composition including inorganic ions, organic carbon (OC), elemental carbon (EC), and inorganic elements. Organic matter (OM = 1.6 × OC) was the largest contributor, accounting for 30.2% of PM 2.5 mass concentration, and followed by sulfate (19.8%), ammonium (10.6%), and nitrate (9.7%), with minor contribution from trace species (5.1%), crustal species (4.7%) and EC (2.9%). Sea-salt and biomass burning potassium together contributed less than 2%. At the four sites, higher PM 2.5 and its major components were observed in the northeast monsoon season while lower levels were found in the southwest monsoon season. The periodic PM 2.5 cycle was observed and influenced mainly by rain wash out. However, regular diurnal variations of PM 2.5 with high concentration during daytime were only observed in summer due to the greater production of sulfate and organic aerosols in spite of the fact that the vertical mixing coefficients were lower during nighttime. The relative contributions of secondary inorganic aerosols (sulfate, nitrate, and ammonium) to PM 2.5 increased rapidly while the contribution of OM decreased during the haze episodes. The reconstructed visibility using revised IMPROVE method correlated well with the measured values. At Xiamen and Fuzhou sites, the major contributors of light extinction coefficient were ammonium sulfate, ammonium nitrate, OM and coarse mass, and accounted for more than 80% of the light extinction coefficient on average.

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Section: Chemical Analysismentioning

confidence: 50%

Two-Years PM2.5 Observations at Four Urban Sites along the Coast of Southeastern China

Schwab

Yang

et al. 2015

Aerosol Air Qual. Res.

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“…and WSOC) and light absorption at 365 nm (Abs 365 ) Reche et al, 2012 (Zhang et al, 2008Giannoni et al, 2012;Zhu et al, 2015) and similar to those of polycyclic aromatic hydrocarbons, dicarboxylic acids and other major water soluble ions associated with particulate matter observed in this region in different years Xu et al, 2012a;Wu et al, 2014Wu et al, , 2015aWu et al, , 2015b. As discussed previously, the seasonal pattern can be partly explained by the transport of air masses from upwind sources under the influence of the East Asian monsoons.…”

Section: Source Apportionment Analysismentioning

confidence: 74%

“…During the summer sampling periods, the prevailing wind direction is southeastÁsouthwest ( Supplementary Fig. 2) and the input of clean marine air masses transported over South China Sea could more readily dilute the PM 2.5 along the coastal region (Wu et al, 2015a(Wu et al, , 2015b. Moreover, fewer biomass burning activities were observed in the upwind regions of Philippines during the summer sampling periods, as seen from MODIS fire counts (Supplementary Fig.…”

Section: Source Apportionment Analysismentioning

confidence: 77%

“…The WSOC/OC ratios were on average lower than those measured in biomass burning smoke (48 %, Guo et al, 2014). In summer and fall when the levels of LG were relatively low, both the stronger correlations between WSOC and OC and the higher WSOC/OC ratios could be attributed to the favourable ambient conditions such as the higher concentrations of O 3 , OH and NO 3 × radicals as well as higher temperature and UV intensity for photochemical processes (Sullivan et al, 2004;Seinfeld and Pandis, 2006;Feng et al, 2007;Wu et al, 2015aWu et al, , 2015b. The WSOC/OC ratios obtained in this study (18.9Á46.7 %) were comparable with those reported in fall-winter in PRD (38.8Á57.9%, Ding et al, 2013) but lower than those in Beijing (38.8Á62.6% annual, Du et al, 2014b), southeastern US (44Á72 % annual, Ding et al, 2008b) and Changdao Island, China (40Á59%, Feng et al, 2007).…”

Section: Relationship Between Lg and Carbon Speciesmentioning

confidence: 81%

“…LG through atmospheric photochemical oxidation which depends on ambient atmospheric conditions in each sampling periods (Hennigan et al, 2010;Cheng et al, 2013;Wu et al, 2015b).…”

Section: Source Apportionment Analysismentioning

confidence: 99%

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Biomass burning contributions to urban PM<sub>2.5</sub> along the coastal lines of southeastern China

Wu¹,

Zhang²,

Schwab³

et al. 2016

Tellus B: Chemical and Physical Meteorology

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A B S T R A C T Levoglucosan (LG), water soluble organic carbon (WSOC) and potassium (K '), and the light absorption at 365 nm (Abs 365 ) of the extracted WSOC are measured in PM 2.5 samples collected from November 2011 to July 2013 at four coastal urban sites in southeast China (Fuzhou, Putian, Quanzhou and Xiamen). These species are markers of biomass burning and used to determine the contributions of biomass burning to the PM 2.5 burden in these locations. LG and WSOC concentrations exhibited a clear seasonal pattern, with a large enhancement in winter and spring and a minimum in summer, and annual means across all sites of 59.2946.8 ng m (3 and 2.6991.21 mg C m (3 , respectively. The distinctive seasonal patterns of LG and WSOC are more explained by the East Asian monsoon than the upwind varying emission sources according to the HYSPLIT backward trajectories and MODIS fire spots. Observations produced significant correlation (at the p B0.01 level) between LG and non-sea salt K ' (nss-K ' ) at each site, but the correlations exhibited no clear seasonal trend. The LG/nss-K ' ratios ranged from 0.0390.01 to 0.2490.13 which lay within the limits for the crop residues and/or grass combustion smoke. Stronger correlations were found between WSOC or Abs 365 and sulphate than between WSOC and LG. This observation is consistent with the fact that biomass burning is a less important contributor to WSOC and/or brown carbon than is secondary organic aerosol formation and oxidation. The average relative contributions of biomass burning to OC and WSOC in PM 2.5 were 8.3 and 15.2 %, respectively, estimated by the measured LG to OC and WSOC (LG/OC and LG/WSOC) ratios in comparison to literature-derived LG/OC and LG/WSOC values for biomass burning smoke. Using the reported conversion factor of LG to PM 2.5 for crop straw burning smoke, the LG-estimated PM 2.5 contributions from biomass burning exhibited minimum values in summer and higher values in winter and spring. Positive Matrix Factorisation was used to analyse PM 2.5 sources, and seven major source factors including biomass burning emissions were resolved. The biomass burning sources contributed 3.75Á8.08 % to PM 2.5 mass as an annual average while exhibiting a seasonal variability similar to and higher than those of LG-estimated contributions. These results demonstrate that the contribution from biomass burning smoke to PM 2.5 Á while small Á is non-negligible, especially in the winter and spring sampling periods, that is, northeastern monsoon season.

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Water-soluble dicarboxylic acids, oxoacids and α-dicarbonyls in the tropical aerosols in coastal megacity Mumbai: molecular characteristics and formation processes

et al. 2022

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Daytime and nighttime PM 10 samples were collected during summer (June) and winter (February) at a representative urban site in Mumbai, located on the western coast of Indian subcontinent. Samples were studied for molecular distribution of water-soluble dicarboxylic acids, oxoacids and dicarbonyls as well as total carbon (TC), water-soluble organic carbon (WSOC), inorganic ions along with speci c markers (levoglucosan, K + ) to better understand sources and formation processes of organic aerosols in Mumbai.The distribution of water-soluble organics was characterised by high abundance of oxalic acid (C 2 ), followed by phthalic (Ph), terephthalic (tPh), azelaic (C 9 ), malonic (C 3 ), and succinic acids (C 4 ). Positive correlation between C 2 , sulfate and glyoxal (ωC 2 ) suggest secondary production of C 2 predominantly via aqueous phase chemistry. C 2 also showed positive correlation with K + and levoglucosan indicating that biomass/biofuel burning is the potential source of diacids in the Mumbai aerosols. In addition, higher average contributions of total diacids to WSOC and OC in winter than in summer suggest that aerosols were aged i.e., photochemically well processed in winter in Mumbai. On the other hand, diurnal change in their ratios is observed with higher ratio in daytime samples than that of previous and succeeding nighttime samples, suggesting diacids are also in uenced from local sources in both the seasons. This study demonstrates that biomass burning as well as biogenic sources are important sources in uencing the distributions of aerosols in Mumbai.

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Seasonal variations and source identification of selected organic acids associated with PM10 in the coastal area of Southeastern China

Cited by 35 publications

References 64 publications

Two-Years PM2.5 Observations at Four Urban Sites along the Coast of Southeastern China

Two-Years PM2.5 Observations at Four Urban Sites along the Coast of Southeastern China

Biomass burning contributions to urban PM<sub>2.5</sub> along the coastal lines of southeastern China

Water-soluble dicarboxylic acids, oxoacids and α-dicarbonyls in the tropical aerosols in coastal megacity Mumbai: molecular characteristics and formation processes

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