scholarly journals Supplementary material to "Large contributions of biogenic and anthropogenic sources to fine organic aerosols in Tianjin, North China"

2019 ◽  
Author(s):  
Yanbing Fan ◽  
Cong-Qiang Liu ◽  
Linjie Li ◽  
Lujie Ren ◽  
Hong Ren ◽  
...  
Keyword(s):  
North China ◽  
Organic Aerosols ◽  
Anthropogenic Sources ◽  
Supplementary Material ◽  
Fine Organic

scholarly journals Large contributions of biogenic and anthropogenic sources to fine organic aerosols in Tianjin, North China

2020 ◽  
Vol 20 (1) ◽  
pp. 117-137 ◽  
Author(s):  
Yanbing Fan ◽  
Cong-Qiang Liu ◽  
Linjie Li ◽  
Lujie Ren ◽  
Hong Ren ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Organic Carbon ◽  
Biomass Burning ◽  
North China ◽  
Fungal Spores ◽  
Organic Aerosols ◽  
Fatty Alcohols ◽  
Molecular Composition ◽  
Anthropogenic Sources ◽  
Night Time

Abstract. In order to better understand the molecular composition and sources of organic aerosols in Tianjin, a coastal megacity in North China, ambient fine aerosol (PM2.5) samples were collected on a day/night basis from November to December 2016 and from May to June 2017. The organic molecular composition of PM2.5 components, including aliphatic lipids (n-alkanes, fatty acids, and fatty alcohols), sugar compounds, and photooxidation products from isoprene, monoterpene, β-caryophyllene, naphthalene, and toluene, was analysed using gas chromatography–mass spectrometry. Fatty acids, fatty alcohols, and saccharides were identified as the most abundant organic compound classes among all of the tracers detected in this study during both seasons. High concentrations of most organics at night in winter may be attributed to intensive residential activities such as house heating as well as the low nocturnal boundary layer height. Based on tracer methods, the contributions of the sum of primary and secondary organic carbon (POC and SOC respectively) to aerosol organic carbon (OC) were 24.8 % (daytime) and 27.6 % (night-time) in winter and 38.9 % (daytime) and 32.5 % (night-time) in summer. In detail, POC derived from fungal spores, plant debris, and biomass burning accounted for 2.78 %–31.6 % (12.4 %; please note that values displayed in parentheses in the following are average values) of OC during the daytime and 4.72 %–45.9 % (16.3 %) at night in winter, and 1.28 %–9.89 % (5.24 %) during the daytime and 2.08 %–47.2 % (10.6 %) at night in summer. Biomass-burning-derived OC was the predominant source of POC in this study, especially at night (16.0±6.88 % in winter and 9.62±8.73 % in summer). Biogenic SOC from isoprene, α-∕β-pinene, and β-caryophyllene exhibited obvious seasonal and diurnal patterns, contributing 2.23±1.27 % (2.30±1.35 % during the daytime and 2.18±1.19 % at night) and 8.60±4.02 % (8.98±3.67 % and 8.21±4.39 %) to OC in winter and summer respectively. Isoprene and α-∕β-pinene SOC were obviously elevated in summer, especially during the daytime, mainly due to strong photooxidation. Anthropogenic SOC from toluene and naphthalene oxidation showed higher contributions to OC in summer (21.0±18.5 %) than in winter (9.58±3.68 %). In summer, toluene SOC was the dominant contributor to aerosol OC, and biomass burning OC also accounted for a high contribution to OC, especially at night-time; this indicates that land/sea breezes also play an important role in the aerosol chemistry of the coastal city of Tianjin in North China.

scholarly journals Large contributions of biogenic and anthropogenic sources to fine organic aerosols in Tianjin, North China

2019 ◽  
Author(s):  
Yanbing Fan ◽  
Cong-Qiang Liu ◽  
Linjie Li ◽  
Lujie Ren ◽  
Hong Ren ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Organic Carbon ◽  
Biomass Burning ◽  
North China ◽  
Fungal Spores ◽  
Organic Aerosols ◽  
Fatty Alcohols ◽  
Anthropogenic Sources ◽  
Gas Chromatography Mass Spectrometry ◽  
Seasonal And Diurnal Variations

Abstract. In order to better understand the molecular composition and sources of organic aerosols in Tianjin, a coastal megacity in North China, ambient fine aerosol (PM2.5) samples were collected on a day/night basis during November–December 2016 and May–June 2017. Organic molecular compositions in PM2.5, including aliphatic lipids (n-alkanes, fatty acids and fatty alcohols), sugar compounds and photooxidation products from isoprene, monoterpene, β-caryophyllene, naphthalene and toluene, were analysed using gas chromatography-mass spectrometry. Fatty acids, fatty alcohols and saccharides were identified as the most abundant organic compound classes among all the tracers during both seasons. High concentrations of most organics at night in winter may be attributed to intensive residential activities such as house heating and the low boundary layer height. Based on the tracer methods, the contributions of the sum of primary and secondary organic carbon (POC and SOC) to aerosol organic carbon (OC) were 24.8 % (daytime) versus 27.6 % (nighttime) in winter and 38.9 % (daytime) versus 32.5 % (nighttime) in summer. In detail, POC derived from fungal spores, plant debris, and biomass burning accounted for 2.78–31.6 % (12.4 %) of OC in the daytime versus 4.72–45.9 % (16.3 %) at night in winter, and 1.28–9.89 % (5.24 %) versus 2.08–47.2 % (10.6 %) in summer. Biomass burning derived OC was the predominant source of POC in this study, especially at night (16.0 ± 6.88 % in winter and 9.62 ± 8.73 % in summer). Biogenic SOC from isoprene, α/β-pinene and β-caryophyllene exhibited obvious seasonal and diurnal variations, contributing 2.23 ± 1.27 % (2.30 ± 1.35 % in the daytime and 2.18 ± 1.19 % at night) and 8.60 ± 4.02 % (8.98 ± 3.67 % and 8.21 ± 4.39 %) to OC in winter and summer, respectively. Isoprene and α/β-pinene SOC were obviously elevated in summer, especially in the daytime, mainly due to strong photooxidation. Anthropogenic SOC from toluene and naphthalene oxidation contributed higher to OC in summer (21.0 ± 18.5 %) than in winter (9.58 ± 3.68 %). In summer, toluene SOC was the dominant contributor to aerosol OC, and biomass burning OC also accounted for a large portion to OC, especially in the nighttime, which indicate that land/sea breezes also play an important role in aerosol chemistry at the coastal city of Tianjin in North China.

scholarly journals Simulation of fine organic aerosols in the western Mediterranean area during the ChArMEx 2013 summer campaign

2018 ◽  
Vol 18 (10) ◽  
pp. 7287-7312 ◽  
Author(s):  
Arineh Cholakian ◽  
Matthias Beekmann ◽  
Augustin Colette ◽  
Isabelle Coll ◽  
Guillaume Siour ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Mass Concentration ◽  
Organic Aerosols ◽  
Western Mediterranean ◽  
Basis Set ◽  
Aerosol Formation ◽  
Standard Scheme ◽  
Western Mediterranean Basin ◽  
The Mediterranean ◽  
Fine Organic

Abstract. The simulation of fine organic aerosols with CTMs (chemistry–transport models) in the western Mediterranean basin has not been studied until recently. The ChArMEx (the Chemistry-Aerosol Mediterranean Experiment) SOP 1b (Special Observation Period 1b) intensive field campaign in summer of 2013 gathered a large and comprehensive data set of observations, allowing the study of different aspects of the Mediterranean atmosphere including the formation of organic aerosols (OAs) in 3-D models. In this study, we used the CHIMERE CTM to perform simulations for the duration of the SAFMED (Secondary Aerosol Formation in the MEDiterranean) period (July to August 2013) of this campaign. In particular, we evaluated four schemes for the simulation of OA, including the CHIMERE standard scheme, the VBS (volatility basis set) standard scheme with two parameterizations including aging of biogenic secondary OA, and a modified version of the VBS scheme which includes fragmentation and formation of nonvolatile OA. The results from these four schemes are compared to observations at two stations in the western Mediterranean basin, located on Ersa, Cap Corse (Corsica, France), and at Cap Es Pinar (Mallorca, Spain). These observations include OA mass concentration, PMF (positive matrix factorization) results of different OA fractions, and 14C observations showing the fossil or nonfossil origins of carbonaceous particles. Because of the complex orography of the Ersa site, an original method for calculating an orographic representativeness error (ORE) has been developed. It is concluded that the modified VBS scheme is close to observations in all three aspects mentioned above; the standard VBS scheme without BSOA (biogenic secondary organic aerosol) aging also has a satisfactory performance in simulating the mass concentration of OA, but not for the source origin analysis comparisons. In addition, the OA sources over the western Mediterranean basin are explored. OA shows a major biogenic origin, especially at several hundred meters height from the surface; however over the Gulf of Genoa near the surface, the anthropogenic origin is of similar importance. A general assessment of other species was performed to evaluate the robustness of the simulations for this particular domain before evaluating OA simulation schemes. It is also shown that the Cap Corse site presents important orographic complexity, which makes comparison between model simulations and observations difficult. A method was designed to estimate an orographic representativeness error for species measured at Ersa and yields an uncertainty of between 50 and 85 % for primary pollutants, and around 2–10 % for secondary species.

scholarly journals Long-term Particulate Matter Modeling for Health Effects Studies in California – Part II: Concentrations and Sources of Ultrafine Organic Aerosols

2016 ◽  
Author(s):  
Jianlin Hu ◽  
Shantanu Jathar ◽  
Hongliang Zhang ◽  
Qi Ying ◽  
Shu-Hua Chen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Health Effects ◽  
Waste Disposal ◽  
Size Fraction ◽  
Organic Aerosols ◽  
Epidemiological Studies ◽  
Anthropogenic Sources ◽  
Major Constituent ◽  
Spatial Distributions ◽  
Mobile Emissions

Abstract. Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0.1). Recent epidemiological studies have identified associations between PM0.1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0.1 in California for a 9-year (2000–2008) modeling period with 4 km horizontal resolution to provide more insights about PM0.1 OA for health effects studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2.5) total organic carbon at six major urban sites had mean fractional bias of −0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2.5 SOA/OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2 ~ 3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0.1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0.1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0.1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0.1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of SOA model, although the absolute amount of SOA can change significantly. Therefore, the spatial distributions of PM0.1 POA and SOA over the 9-year study period provide useful information for epidemiological studies to further investigate the associations with health outcomes.

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