scholarly journals Organic and inorganic compositions of marine aerosols from East Asia: Seasonal variations of water-soluble dicarboxylic acids, major ions, total carbon and nitrogen, and stable C and N isotopic composition

2004 ◽  
pp. 243-265 ◽  
Author(s):  
Kimitaka Kawamura ◽  
Minoru Kobayashi ◽  
Nobuyuki Tsubonuma ◽  
Michihiro Mochida ◽  
Tomomi Watanabe ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
East Asia ◽  
Seasonal Variations ◽  
Major Ions ◽  
Dicarboxylic Acids ◽  
Water Soluble ◽  
Total Carbon ◽  
Marine Aerosols ◽  
Carbon And Nitrogen ◽  
C And N

scholarly journals Seasonal study of stable carbon and nitrogen isotopic composition in fine aerosols at a Central European rural background station

2019 ◽  
Vol 19 (6) ◽  
pp. 3463-3479 ◽  
Author(s):  
Petr Vodička ◽  
Kimitaka Kawamura ◽  
Jaroslav Schwarz ◽  
Bhagawati Kunwar ◽  
Vladimír Ždímal
Keyword(s):  
Seasonal Variation ◽  
Isotopic Composition ◽  
Ambient Temperature ◽  
Biomass Burning ◽  
Isotope Ratios ◽  
Water Soluble ◽  
Total Carbon ◽  
Stable Carbon ◽  
Δ13c Values ◽  
Rural Background

Abstract. A study of the stable carbon isotope ratios (δ13C) of total carbon (TC) and the nitrogen isotope ratios (δ15N) of total nitrogen (TN) was carried out for fine aerosol particles (PM1) and was undertaken every 2 days with a 24 h sampling period at a rural background site in Košetice (Central Europe) from 27 September 2013 to 9 August 2014 (n=146). We found a seasonal pattern for both δ13C and δ15N. The seasonal variation in δ15N was characterized by lower values (average of 13.1±4.5 ‰) in winter and higher values (25.0±1.6 ‰) in summer. Autumn and spring were transition periods when the isotopic composition gradually changed due to the changing sources and ambient temperature. The seasonal variation in δ13C was less pronounced but more depleted in 13C in summer (-27.8±0.4 ‰) as compared to winter (-26.7±0.5 ‰). A comparative analysis with water-soluble ions, organic carbon, elemental carbon, trace gases and meteorological parameters (mainly ambient temperature) has shown major associations with the isotopic compositions, which has provided greater knowledge and understanding of the corresponding processes. A comparison of δ15N with NO3-, NH4+ and organic nitrogen (OrgN) revealed that although a higher content of NO3- was associated with a decrease in the δ15N of TN, NH4+ and OrgN caused increases. The highest concentrations of nitrate, mainly represented by NH4NO3 related to the emissions from biomass burning leading to an average δ15N of TN (13.3 ‰) in winter. During spring, the percentage of NO3- in PM1 decreased. An enrichment of 15N was probably driven by the equilibrium exchange between the gas and aerosol phases (NH3(g) ↔ NH4+(p)), which is supported by the increased ambient temperature. This equilibrium was suppressed in early summer when the molar ratios of NH4+/SO42- reached 2, and the nitrate partitioning in aerosol was negligible due to the increased ambient temperature. Summertime δ15N values were among the highest, suggesting the aging of ammonium sulfate and OrgN aerosols. Such aged aerosols can be coated by organics in which 13C enrichment takes place by the photooxidation process. This result was supported by a positive correlation of δ13C with ambient temperature and ozone, as observed in the summer season. During winter, we observed an event with the lowest δ15N and highest δ13C values. The winter event occurred in prevailing southeast air masses. Although the higher δ13C values probably originated from biomass-burning particles, the lowest δ15N values were probably associated with agriculture emissions of NH3 under low-temperature conditions (< 0 ∘C).

scholarly journals Dicarboxylic acids, metals and isotopic compositions of C and N in atmospheric aerosols from inland China: implications for dust and coal burning emission and secondary aerosol formation

2010 ◽  
Vol 10 (13) ◽  
pp. 6087-6096 ◽  
Author(s):  
G. Wang ◽  
M. Xie ◽  
S. Hu ◽  
S. Gao ◽  
E. Tachibana ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Strong Dependence ◽  
Inversion Layer ◽  
Stable Carbon Isotope ◽  
Dicarboxylic Acids ◽  
Water Soluble ◽  
Total Carbon ◽  
Aerosol Formation ◽  
Coal Burning ◽  
Isotopic Compositions

Abstract. Dicarboxylic acids (C2–C10), metals, elemental carbon (EC), organic carbon (OC), and stable isotopic compositions of total carbon (TC) and total nitrogen (TN) were determined for PM10 samples collected at three urban and one suburban sites of Baoji, an inland city of China, during winter and spring 2008. Oxalic acid (C2) was the dominant diacid, followed by succinic (C4) and malonic (C3) acids. Total diacids in the urban and suburban areas were 1546±203 and 1728±495 ng m−3 during winter and 1236±335 and 1028±193 ng m−3 during spring. EC in the urban and the suburban atmospheres were 17±3.8 and 8.0±2.1 μg m−3 during winter and 20±5.9 and 7.1±2.7 μg m−3 during spring, while OC at the urban and suburban sites were 74±14 and 51±7.9 μg m−3 in winter and 51±20 and 23±6.1 μg m−3 in spring. Secondary organic carbon (SOC) accounted for 38±16% of OC in winter and 28±18% of OC in spring, suggesting an enhanced photochemical production of secondary organic aerosols in winter under an inversion layer development. Total metal elements in winter and spring were 34±10 and 61±27 μg m−3 in the urban air and 18±7 and 32±23 μg m−3 in the suburban air. A linear correlation (r2>0.8 in winter and r2>0.6 in spring) was found between primary organic carbon (POC) and Ca2+/Fe, together with a strong dependence of pH value of sample extracts on water-soluble inorganic carbon, suggesting fugitive dust as an important source of the airborne particles. Polycyclic aromatic hydrocarbons (PAHs), sulfate, and Pb in the samples well correlated each other (r2>0.6) in winter, indicating an importance of emissions from coal burning for house heating. Stable carbon isotope compositions of TC (δ13C) became higher with an increase in the concentration ratios of C2/OC due to aerosol aging. In contrast, nitrogen isotope compositions of TN (δ15N) became lower with an increases in the mass ratios of NH4+/PM10 and NO3−/PM10, which is possibly caused by an enhanced adsorption and/or condensation of gaseous NH3 and HNO3 onto particles.

scholarly journals Diurnal variations of total carbon, dicarboxylic acids, ketoacids and α-dicarbonyls in aerosols in the northern vicinity of Beijing

2013 ◽  
Vol 13 (6) ◽  
pp. 16699-16731 ◽  
Author(s):  
N. He ◽  
K. Kawamura ◽  
K. Okuzawa ◽  
Y. Kanaya ◽  
Z. F. Wang
Keyword(s):  
Atmospheric Transport ◽  
Glyoxylic Acid ◽  
Dicarboxylic Acids ◽  
Abundant Species ◽  
Photochemical Oxidation ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Marine Aerosols ◽  
Night Time ◽  
Aerosol Mass

Abstract. Aerosol samples (TSP, n=58) were collected on day- and night-time basis at Mangshan in the north of Beijing, China in autumn 2007 to better understand the status of air quality and the influence of urban pollutants in the northern vicinity of Beijing. The samples were analyzed for aerosol mass, total carbon (TC), low molecular weight α, ω-dicarboxylic acids (C2-C12), ketoacids (ωC2-ωC9, pyruvic acid), α-dicarbonyls (glyoxal and methylglyoxal), as well as aromatic (phthalic, iso- and tere-phthalic) diacids. Aerosol mass and TC concentrations are higher in daytime than in nighttime. TC/aerosol mass ratios in this study are lower than those reported in megacities in East Asia, but higher than those reported in marine aerosols. Molecular distributions of diacids demonstrated that oxalic (C2) acid was the most abundant species, comprising 38–77% of total diacids, followed by succinic (C4) and malonic (C3) acids. For most compounds, the concentrations were higher in daytime than nighttime, indicating that diacids are produced in daytime by photochemical oxidation of organic precursors emitted from anthropogenic sources in Beijing during the transport to Mangshan area by the northward wind. However, we found that C2 concentrations are higher in nighttime than in daytime. A positive correlation of C2 to glyoxylic acid (ωC2) was obtained at night when relative humidity increased up to 100%, suggesting that aqueous phase production of C2 occurs in nighttime via the oxidation of ωC2. Depletion of C2 by photolysis of Fe-oxalato complexes might be another reason for the lower concentrations of C2 in daytime samples. High phthalic acid/C4 ratios in the aerosol samples suggest that automobile combustion and coal burning products are important sources, which are subjected to photochemical oxidation during the atmospheric transport of urban aerosols from Beijing. In contrast, higher concentrations of methylglyoxal in nighttime than daytime may suggest that isoprene emitted from the northern forest area is oxidized in daytime and then transported to the sampling area at night by northerly winds. This study demonstrates that secondary organic aerosols are significantly produced and aged in the vicinity of Beijing during atmospheric transport.

scholarly journals Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer

2012 ◽  
Vol 9 (11) ◽  
pp. 4725-4737 ◽  
Author(s):  
K. Kawamura ◽  
K. Ono ◽  
E. Tachibana ◽  
B. Charriére ◽  
R. Sempéré
Keyword(s):  
Oxalic Acid ◽  
Arctic Ocean ◽  
Late Summer ◽  
Dicarboxylic Acids ◽  
Water Soluble ◽  
The Arctic ◽  
Marine Atmosphere ◽  
Marine Aerosols ◽  
Δ13c Values ◽  
The Arctic Ocean

Abstract. Oxalic and other small dicarboxylic acids have been reported as important water-soluble organic constituents of atmospheric aerosols from different environments. Their molecular distributions are generally characterized by the predominance of oxalic acid (C2) followed by malonic (C3) and/or succinic (C4) acids. In this study, we collected marine aerosols from the Arctic Ocean during late summer in 2009 when sea ice was retreating. The marine aerosols were analyzed for the molecular distributions of dicarboxylic acids as well as ketocarboxylic acids and α-dicarbonyls to better understand the source of water-soluble organics and their photochemical processes in the high Arctic marine atmosphere. We found that diacids are more abundant than ketoacids and α-dicarbonyls, but their concentrations are generally low (< 30 ng m−3), except for one sample (up to 70 ng m−3) that was collected near the mouth of Mackenzie River during clear sky condition. Although the molecular compositions of diacids are in general characterized by the predominance of oxalic acid, a depletion of C2 was found in two samples in which C4 became the most abundant. Similar depletion of oxalic acid has previously been reported in the Arctic aerosols collected at Alert after polar sunrise and in the summer aerosols from the coast of Antarctica. Because the marine aerosols that showed a depletion of C2 were collected under the overcast and/or foggy conditions, we suggest that a photochemical decomposition of oxalic acid may have occurred in aqueous phase of aerosols over the Arctic Ocean via the photo dissociation of oxalate-Fe (III) complex. We also determined stable carbon isotopic compositions (δ13C) of bulk aerosol carbon and individual diacids. The δ13C of bulk aerosols showed −26.5‰ (range: −29.7 to −24.7‰, suggesting that marine aerosol carbon is derived from both terrestrial and marine organic materials. In contrast, oxalic acid showed much larger δ13C values (average: −20.9‰, range: −24.7‰ to −17.0‰) than those of bulk aerosol carbon. Interestingly, δ13C values of oxalic acid were higher than C3 (av. −26.6‰) and C4 (−25.8‰) diacids, suggesting that oxalic acid is enriched with 13C due to its photochemical processing (aging) in the marine atmosphere.

scholarly journals High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the mountain aerosols over the North China Plain during wheat burning season

2013 ◽  
Vol 13 (2) ◽  
pp. 3695-3734 ◽  
Author(s):  
K. Kawamura ◽  
E. Tachibana ◽  
K. Okuzawa ◽  
S. G. Aggarwal ◽  
Y. Kanaya ◽  
...  
Keyword(s):  
Wheat Straw ◽  
North China Plain ◽  
North China ◽  
Dicarboxylic Acids ◽  
Agricultural Wastes ◽  
Water Soluble ◽  
Total Carbon ◽  
The North ◽  
The North China Plain ◽  
Field Burning

Abstract. Aerosol (TSP) samples were collected at the summit of Mount Tai (elevation: 1534 m a.s.l., 36.25° N; 117.10° E) located in the North China Plain using a high-volume air sampler and pre-combusted quartz filters. Sampling was conducted on day/night or 3 h basis in the period from 29 May to 28 June 2006 during the field burning of wheat straw residue and the post-burning season. The filter samples were analyzed for low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls using capillary gas chromatography (GC) and GC-MS employing water extraction and butyl ester derivatization. Dicarboxylic acids (C2–C11, 220–6070 ng m−3) were characterized by a predominance of oxalic (C2) acid (105–3920 ng m−3) followed by succinic (C4) or malonic (C3) acid. Unsaturated aliphatic diacids, including maleic (M), isomaleic (iM) and fumaric (F) acid, were also detected together with aromatic diacids (phthalic, iso-phthalic and tere-phthalic acids). ω-Oxocarboxylic acids (C2–C9, 24–610 ng m−3) were detected as the second most abundant compound class with the predominance of glyoxylic acid (11–360 ng m−3), followed by α-ketoacid (pyruvic acid, 3–140 ng m−3) and α-dicarbonyls (glyoxal, 1–230 ng m−3 and methylglyoxal, 2–120 ng m−3). We found that these levels (> 6000 ng m−3 for diacids) are several times higher than those reported in Chinese megacities at ground levels. The concentrations of diacids increased from late May to early June showing a maximum on 7 June and then significantly decreased during 8–11 June when the wind direction shifted from northeasterly to northerly. Similar temporal trends were found for ketocarboxylic acids and α-dicarbonyls as well as total carbon (TC) and water-soluble organic carbon (WSOC). The temporal variations of water-soluble organics were interpreted by the direct emission from the field burning products of agricultural wastes (wheat straw) in the North China Plain and the subsequent photochemical oxidation of volatile and semi-volatile organic precursors emitted from field burning. This study demonstrates that the field burning of agricultural wastes in early summer strongly influenced the air quality of the free troposphere over the North China Plain.

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