54 results on '"Eri Tachibana"'
Search Results
2. Abundance, chemical structure, and light absorption properties of humic-like substances (HULIS) and other organic fractions of forest aerosols in Hokkaido
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Sonia Afsana, Ruichen Zhou, Yuzo Miyazaki, Eri Tachibana, Dhananjay Kumar Deshmukh, Kimitaka Kawamura, and Michihiro Mochida
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Medicine ,Science - Abstract
Abstract Atmospheric organic aerosol (OA) are considered as a significant contributor to the light absorption of OA, but its relationship with abundance, composition and sources are not understood well. In this study, the abundance, chemical structural characteristics, and light absorption property of HULIS and other low-to-high polar organics in PM0.95 collected in Tomakomai Experimental Forest (TOEF) were investigated with consideration of their possible sources. HULIS were the most abundant (51%), and correlation analysis revealed that biogenic secondary organic aerosols significantly contribute to HULIS. The mass spectra obtained using a high-resolution aerosol mass spectrometer (HR-AMS) showed that HULIS and highly polar water-soluble organic matter (HP-WSOM) were substantially oxygenated organic aerosol fractions, whereas water-insoluble organic matter (WISOM) had a low O/C ratio and more hydrocarbon-like structures. The WISOM fraction was the predominant light-absorbing organics. HULIS and WISOM showed a noticeable seasonal change in mass absorption efficiency (MAE365), which was highest in winter. Further, HULIS were shown to be less absorbing than those reported for urban sites. The findings in this study provide insights into the contribution of biogenic secondary OA on aerosol property and radiative forcing under varying contributions from other types of OA.
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- 2022
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3. Author Correction: New index of organic mass enrichment in sea spray aerosols linked with senescent status in marine phytoplankton
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Yuzo Miyazaki, Koji Suzuki, Eri Tachibana, Youhei Yamashita, Astrid Müller, Kaori Kawana, and Jun Nishioka
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Medicine ,Science - Published
- 2021
- Full Text
- View/download PDF
4. Subarachnoid hemorrhage-negative Terson syndrome after intracranial artery treatment with a flow diverter device
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Takanori Matsuoka, Satoshi Matsuda, Seiyo Harino, Miho Kumoi, Eri Tachibana, Junko Yokoyama, Chieko Tsujino, Kumiko Kazuo, and Yasumasa Otori
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Flow diverter ,Subarachnoid hemorrhage-negative terson syndrome ,Sub-inner limiting membrane hemorrhage ,Vitreous hemorrhage ,Ophthalmology ,RE1-994 - Abstract
Purpose: To report a case of subarachnoid hemorrhage-negative Terson syndrome following intracranial artery treatment with flow diverter stents. Observations: A 40-year-old Asian woman presented with floaters in her right eye after treatment of an intracranial aneurysm with flow diverter stents. Vitreous hemorrhage and sub-inner limiting membrane (sub-ILM) hemorrhage were present in her right eye. On fluorescein angiography, contrast perfusion and vascular occlusion were not noted. Magnetic resonance imaging (MRI) did not show any evidence of subarachnoid hemorrhage (SAH). We hypothesize that the bleeding was due to Terson syndrome associated with intracranial treatment with the flow diverter stents. During follow-up, the vitreous hemorrhage and sub-ILM hemorrhage disappeared, and the floaters in her vision improved. Conclusions and Importance: This is the first reported case of vitreous hemorrhage and sub-ILM hemorrhage that should be considered to be Terson syndrome, after flow diverter stents treatment in the absence of SAH.
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- 2020
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5. Long-term (2001–2013) observations of water-soluble dicarboxylic acids and related compounds over the western North Pacific: trends, seasonality and source apportionment
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Suresh K. R. Boreddy, Kimitaka Kawamura, and Eri Tachibana
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Medicine ,Science - Abstract
Abstract To better understand the impact of East Asian pollutants on the molecular composition of marine organic aerosols, we conducted long-term (2001–2013) observations of water-soluble dicarboxylic acids and related compounds in total suspended particulate samples collected at Chichijima Island in the western North Pacific (WNP). Seasonal variations of all the diacids and related compounds showed maxima in winter and spring and minima in summer, except for azelaic acid (C9), which maximized in summer to autumn. The overall annual concentrations of the total diacids, ω-oxoacids and α-dicarbonyls showed an increase during 2001–2013. We found a significant (p 0.05) acids, and methylglyoxal (MeGly). In contrast, phthalic acid (p < 0.05) and glyoxal (Gly) showed a decrease in their trends. We also found a significant decrease in the trend of the Gly/MeGly mass ratios. These results demonstrate that the enhanced concentrations of diacids over the WNP are majorly attributed to the aqueous-phase photooxidation of biogenic volatile organic compounds from East Asia followed by long-range atmospheric transport. Further, positive matrix factorization analysis showed a biogenic photochemical contribution (42%) was the dominant source of oxalic acid in the WNP.
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- 2017
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6. Evidence of a reduction in cloud condensation nuclei activity of water-soluble aerosols caused by biogenic emissions in a cool-temperate forest
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Astrid Müller, Yuzo Miyazaki, Eri Tachibana, Kimitaka Kawamura, and Tsutom Hiura
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Medicine ,Science - Abstract
Abstract Biogenic organic aerosols can affect cloud condensation nuclei (CCN) properties, and subsequently impact climate change. Large uncertainties exist in how the difference in the types of terrestrial biogenic sources and the abundance of organics relative to sulfate affect CCN properties. For the submicron water-soluble aerosols collected for two years in a cool-temperate forest in northern Japan, we show that the hygroscopicity parameter κCCN (0.44 ± 0.07) exhibited a distinct seasonal trend with a minimum in autumn (κCCN = 0.32–0.37); these κCCN values were generally larger than that of ambient particles, including water-insoluble fractions. The temporal variability of κCCN was controlled by the water-soluble organic matter (WSOM)-to-sulfate ratio (R2 > 0.60), where the significant reduction of κCCN in autumn was linked to the increased WSOM/sulfate ratio. Positive matrix factorization analysis indicates that α-pinene-derived secondary organic aerosol (SOA) substantially contributed to the WSOM mass (~75%) in autumn, the majority of which was attributable to emissions from litter/soil microbial activity near the forest floor. These findings suggest that WSOM, most likely α-pinene SOA, originated from the forest floor can significantly suppress the aerosol CCN activity in cool-temperate forests, which have implications for predicting climate effects by changes in biogenic emissions in future.
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- 2017
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7. Blowout Fracture after Descemet's Stripping Automated Endothelial Keratoplasty
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Eri Tachibana, Shizuka Koh, Naoyuki Maeda, and Kohji Nishida
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Descemet’s stripping automated endothelial keratoplasty ,Corneal transplantation ,Blowout fracture ,Ophthalmology ,RE1-994 - Abstract
We present the case of an 86-year-old woman who developed a blowout fracture after Descemet's stripping automated endothelial keratoplasty (DSAEK). Sixteen months after DSAEK, she suffered a blow to her left eye caused by a fall. Computed tomography confirmed the presence of a blowout fracture of the inferior wall of the left orbit with soft tissue prolapsing into the orbit. The patient complained of no abnormal symptoms, and her operated cornea was intact and clear. There was no abnormal finding in both the anterior and posterior segments. This case highlights that the DSAEK technique provides adequate tectonic stability of the globe throughout the traumatic event in contrast to penetrating keratoplasty, which can lead to devastating vision damage after trauma.
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- 2014
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8. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, glyoxylic acid and glyoxal in tropical aerosols: implications for photochemical processes of organic aerosols
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Stelyus L. Mkoma, Kimitaka Kawamura, and Eri Tachibana
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PM2.5 and PM10 ,stable carbon isotope ratios ,oxalic acid ,diacids ,glyoxylic acid ,glyoxal ,organic aerosols ,Tanzania ,East Africa ,Meteorology. Climatology ,QC851-999 - Abstract
Tropical aerosols of PM2.5 and PM10 were collected at a rural site in Morogoro, Tanzania (East Africa), and analysed for stable carbon isotopic composition (δ13C) of dicarboxylic acids (C2–C9), glyoxylic acid (ωC2) and glyoxal (Gly) using gas chromatography/isotope ratio mass spectrometer. PM2.5 samples showed that δ13C of oxalic (C2) acid are largest (mean, −18.3±1.7‰) followed by malonic (C3, −19.6±1.0‰) and succinic (C4, −21.8±2.2‰) acids, whereas those in PM10 are a little smaller: −19.9±3.1‰ (C2), −20.2±2.7‰ (C3) and −23.3±3.2‰ (C4). The δ13C of C2–C4 diacids showed a decreasing trend with an increase in carbon numbers. The higher δ13C values of oxalic acid can be explained by isotopic enrichment of 13C in the remaining C2 due to the atmospheric decomposition of oxalic acid or its precursors. δ13C of ωC2 and Gly that are precursors of oxalic acid also showed larger values (mean, −22.5‰ and −20.2‰, respectively) in PM2.5 than those (−26.7‰ and −23.7‰) in PM10. The δ13C values of ωC2 and Gly are smaller than those of C2 in both PM2.5 and PM10. On the other hand, azelaic acid (C9; mean, −28.5‰) is more depleted in 13C, which is consistent with the previous knowledge; that is, C9 is produced by the oxidation of unsaturated fatty acids emitted from terrestrial higher plants. A significant enrichment of 13C in oxalic acid together with its negative correlations with relative abundance of C2 in total diacids and ratios of water-soluble organic carbon and organic carbon further support that a photochemical degradation of oxalic acid occurs during long-range transport from source regions.
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- 2014
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9. Stable carbon and nitrogen isotopic compositions of tropical atmospheric aerosols: sources and contribution from burning of C3 and C4 plants to organic aerosols
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Stelyus L. Mkoma, Kimitaka Kawamura, Eri Tachibana, and Pingqing Fu
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PM2.5 and PM10 ,aerosols ,isotopic composition of total carbon and nitrogen ,C3 and C4 plants ,Tanzania ,Meteorology. Climatology ,QC851-999 - Abstract
In this paper, we report for the first time the δ13C and δ15N data for PM2.5 and PM10 aerosols collected in Tanzania during May–August 2011 together with total carbon (TC) and nitrogen (TN) contents. Mean TC concentrations were 6.5±2.1 µg m−3 in PM2.5 and 9.2±3.5 µg m−3 in PM10. δ13C of TC ranged from −26.1 to −20.6‰ with a mean of −23.6‰ in PM2.5 and from −24.4 to −22.4‰ with a mean of −23.6‰ in PM10. We found substantially greater δ13C values in PM2.5 samples during dry season as well as strong positive correlation between levoglucosan (and nss-K+) and TC in PM2.5. These results suggest a significant contribution from burning of C4 plants to fine organic aerosol formation. TN contents showed a mean of 0.7±0.3 µg m−3 in PM2.5 and 0.8±0.2 µg m−3 in PM10. δ15N ranged from +13.4 to +22.1‰ with a mean of +16.2±2.7‰ in PM2.5 and +10.4 to +18.7‰ with a mean of +13.7±2.2‰ in PM10. δ15N showed higher ratios in fine particles than coarse particles in both wet and dry season. The relatively high δ15N values suggest isotopic enrichment of 15N in aerosols via exchange reaction between NH3 (gas) and NH4+ (particle). We found a strong correlation between TN and NH4+(r2=0.94 in PM2.5 and r2=0.86 in PM10) and NO3- (r 2=0.48 in PM2.5 and r2=0.55 in PM10). We also found that organic nitrogen is less significant than inorganic nitrogen in the Morogoro aerosols. Based on stable carbon isotopic composition, contributions of burning C3 plants to TC were estimated to range from 42 to 74% in PM2.5 and from 39 to 64% in PM10, whereas those of C4 ranged from 26 to 58% in PM2.5 and from 36 to 61% in PM10. These results suggest that burning activities of C3 and C4 plants contribute to organic aerosol formation in Tanzania.
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- 2014
- Full Text
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10. Marine nitrogen fixation as a possible source of atmospheric water-soluble organic nitrogen aerosols in the subtropical North Pacific
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Tsukasa Dobashi, Yuzo Miyazaki, Eri Tachibana, Kazutaka Takahashi, Sachiko Horii, Fuminori Hashihama, Saori Yasui-Tamura, Yoko Iwamoto, Shu-Kuan Wong, and Koji Hamasaki
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Ecology, Evolution, Behavior and Systematics ,Earth-Surface Processes - Abstract
Water-soluble organic nitrogen (WSON) in marine atmospheric aerosols affect the water solubility, acidity, and light-absorbing properties of aerosol particles, which are important parameters in assessing both the climate impact and the biogeochemical cycling of bioelements. Size-segregated aerosol and surface seawater (SSW) samples were simultaneously collected over the subtropical North Pacific to investigate the origin of WSON in the marine atmosphere. The fine-mode WSON concentration (7.5 ± 6.6 ngN m−3) at 200–240∘ E along 23∘ N, defined as the eastern North Pacific (ENP), was significantly higher than that (2.4 ± 1.9 ngN m−3) at 135–200∘ E, defined as the western North Pacific (WNP). Analysis of the stable carbon isotope ratio of water-soluble organic carbon (WSOC; δ13CWSOC) together with backward trajectory indicated that most of the observed WSON in the fine particles in the ENP originated from the ocean surface. We found positive relations among nitrogen-fixation rate, dissolved organic nitrogen (DON) in SSW, and the WSON concentrations. The result suggests that reactive nitrogen (DON and ammonium), produced and exuded by nitrogen-fixing microorganisms in SSW, contributed to the formation of WSON aerosols. This study provides new insights into the role of ocean-derived reactive nitrogen aerosols associated with marine microbial activity.
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- 2023
11. Origin of secondary fatty alcohols in atmospheric aerosols in a cool-temperate forest based on their mass size distributions
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Yuhao Cui, Eri Tachibana, Kimitaka Kawamura, and Yuzo Miyazaki
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Fatty alcohols (FAs) are major components of surface lipids in plant leaves and serve as surface-active organic aerosols (OAs), which can act as primary biological aerosol particles (PBAPs). To elucidate the origin and formation of secondary fatty alcohols (SFAs) in atmospheric aerosols, their mass size distribution in aerosol samples obtained from a deciduous forest canopy was measured in spring, summer, and autumn. The SFAs showed the highest concentration in spring (growing season), with n-nonacosan-10-ol being the most abundant. In spring and summer, the size peak of n-nonacosan-10-ol was in particle size range >10.0 μm, whereas it was in the 1.9–3.0 μm range in autumn. The size distribution of n-nonacosan-10-ol did not show any significant correlation with that of the known biogenic tracers of pollen, soil, and fungal spores in spring and summer. The overall results, together with SFAs measured in plant leaves, as well as the literature, suggest that SFAs originate mostly from plant waxes, and that leaf senescence status is likely an important factor controlling the size distribution of SFAs. This study provides new insights into the possible sources of PBAPs and their effects on the ice nucleation activity of aerosols based on seasonal changes in particle size.
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- 2023
12. Supplementary material to 'Origin of secondary fatty alcohols in atmospheric aerosols in a cool-temperate forest based on their mass size distributions'
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Yuhao Cui, Eri Tachibana, Kimitaka Kawamura, and Yuzo Miyazaki
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- 2023
13. Offline analysis of the chemical composition and hygroscopicity of submicrometer aerosol at an Asian outflow receptor site and comparison with online measurements
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Kojiro Shimada, Yuzo Miyazaki, Hanbing Xu, Yutaka Kondo, Dhananjay K. Deshmukh, Fei Li, Hiroaki Fujinari, Hikari Yai, Eri Tachibana, Yange Deng, Tomoki Nakayama, Mingfu Cai, Akinori Takami, Kimitaka Kawamura, Sho Ohata, Shiori Tatsuta, Michihiro Mochida, Shiro Hatakeyama, and Haobo Tan
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chemistry.chemical_classification ,chemistry.chemical_compound ,Atmospheric Science ,chemistry ,Differential mobility analyzer ,Analytical chemistry ,Particle ,Organic matter ,Sulfate ,Mass spectrometry ,Chemical composition ,Mass fraction ,Aerosol - Abstract
Filter-based offline analysis of atmospheric aerosol hygroscopicity coupled to composition analysis provides information complementary to that obtained from online analysis. However, its application itself and comparison to online analysis have remained limited to date. In this study, daily submicrometer aerosol particles (PM0.95, 50 % cutoff diameter: 0.95 μm) were collected onto quartz fiber filters in Okinawa Island, a receptor of East Asian outflow, in the autumn of 2015. The chemical composition of water-soluble matter (WSM) in PM0.95 and PM0.95 itself, and their respective hygroscopicities were characterized through the offline use of an aerosol mass spectrometer and a hygroscopicity tandem differential mobility analyzer. Thereafter, results were compared with those obtained from online analyses. Sulfate dominated the WSM mass (60 %), followed by water-soluble organic matter (WSOM, 20 %) and ammonium (13 %). WSOM accounted for most (93 %) of the mass of extracted organic matter (EOM) and the atomic O to C ratios (O : C) of WSOM and EOM were high (mean ± standard deviation were, respectively, 0.84 ± 0.08 and 0.79 ± 0.08), both of which indicate highly aged characteristics of the observed aerosol. The hygroscopic growth curves showed clear hysteresis for most samples. At 85 % RH, the calculated hygroscopicity parameter κ of the WSM (κWSM), WSOM, EOM, and PM0.95 (κPM0.95) were, respectively, 0.50 ± 0.03, 0.22 ± 0.12, 0.20 ± 0.11, and 0.47 ± 0.03. An analysis using the thermodynamic E-AIM model shows, on average, that inorganic salts and WSOM respectively contributed 88 % and 12 % of the κWSM (or κPM0.95). High similarities were found between offline and online analysis for chemical compositions that are related to particle hygroscopicity (the mass fractions and O : C of organics, and the degree of neutralization), and also for aerosol hygroscopicity. As possible factors governing the variation of κWSM, the influences of WSOM abundance and the neutralization of inorganic salts were assessed. At high RH (70–90 %), the hygroscopicity of WSM and PM0.95 was affected considerably by the presence of organic components; at low RH (20–50 %), the degree of neutralization could be important. This study not only characterized aerosol hygroscopicity at the receptor site of East Asian outflow, but also shows that the offline hygroscopicity analysis is an appropriate method, at least for aerosols of the studied type. The results encourage further applications to other environments and to more in-depth hygroscopicity analysis, in particular for organic fractions.
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- 2022
14. Fluorescence of solvent-extractable organics in sub-micrometer forest aerosols in Hokkaido, Japan
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Sonia Afsana, Ruichen Zhou, Yuzo Miyazaki, Eri Tachibana, Dhananjay Kumar Deshmukh, Kimitaka Kawamura, and Michihiro Mochida
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Atmospheric Science ,General Environmental Science - Published
- 2023
15. Origin of secondary fatty alcohols in atmospheric aerosols in a cooltemperate forest based on their mass size distributions.
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Yuhao Cui, Eri Tachibana, Kawamura, Kimitaka, and Yuzo Miyazaki
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FATTY alcohols ,SPRING ,AUTUMN ,ATMOSPHERIC aerosols ,SECONDARY forests ,MICROBIOLOGICAL aerosols ,AEROSOL sampling ,DECIDUOUS forests ,BEE pollen - Abstract
Fatty alcohols (FAs) are major components of surface lipids in plant leaves and serve as surface-active organic aerosols (OAs), which can act as primary biological aerosol particles (PBAPs). To elucidate the origin and formation of secondary fatty alcohols (SFAs) in atmospheric aerosols, their mass size distribution in aerosol samples obtained from a deciduous forest canopy was measured in spring, summer, and autumn. The SFAs showed the highest concentration in spring (growing season), with n-nonacosan-10-ol being the most abundant. In spring and summer, the size peak of n15 nonacosan-10-ol was in particle size range >10.0 µm, whereas it was in the 1.9-3.0 µm range in autumn. The size distribution of n-nonacosan-10-ol did not show any significant correlation with that of the known biogenic tracers of pollen, soil, and fungal spores in spring and summer. The overall results, together with SFAs measured in plant leaves, as well as the literature, suggest that SFAs originate mostly from plant waxes, and that leaf senescence status is likely an important factor controlling the size distribution of SFAs. This study provides new insights into the possible sources of PBAPs and their effects on the ice nucleation activity of aerosols based on seasonal changes in particle size. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
- View/download PDF
16. Supplementary material to 'Marine nitrogen fixation as a possible source of atmospheric water-soluble organic nitrogen aerosols in the subtropical North Pacific'
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Tsukasa Dobashi, Yuzo Miyazaki, Eri Tachibana, Kazutaka Takahashi, Sachiko Horii, Yoko Iwamoto, Shu-Kuan Wong, and Koji Hamasaki
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- 2022
17. Light absorption of forest organic aerosol fractions with different polarity
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Sonia Afsana, Ruichen Zhou, Yuzo Miyazaki, Eri Tachibana, Dhananjay Kumar Deshmukh, Kimitaka Kawamura, and Michihiro Mochida
- Abstract
Organic aerosol (OA) is a ubiquitous component of atmospheric aerosol and affects radiative forcing not only by scattering but also by absorbing solar radiation. The light absorption property of OA should vary depending on its composition, which is not well understood to date. Humic-like substances (HULIS), a medium polar part of OA, constitute significant part of water-soluble organic matter (WSOM) and have light-absorbing capacity. In addition, recent studies showed that less polar water-insoluble organic matter (WISOM) absorbed light stronger than WSOM. Knowledge on the light absorption property of all the parts of OA in atmospheric aerosols is important to understand their contribution to aerosol light absorption. In this study, the light absorption property of extractable organics with low-to-high polarity in submicron aerosols collected at a forest site was characterized.PM0.95 samples (particles with a diameter smaller than 0.95 mm) were collected on quartz filters in Tomakomai Experimental Forest of Hokkaido University, Japan, from June 2012 to May 2013. Organic aerosol components in the samples were extracted and fractionated by the combination of solvent extraction and solid-phase extraction methods. WSOM and WISOM were extracted sequentially by using multiple solvents. HULIS and highly-polar water-soluble organic matter (HP-WSOM) were fractionated from WSOM by solid-phase extraction. The light absorption by the OA fractions were measured using a UV-visible spectrometer. Further, a high-resolution time-of-flight aerosol mass spectrometer was used to quantify the OA fractions and to analyze the types of generated ions.The mass absorption efficiency at 365 nm (MAE365) for WISOM was highest among all OA fractions (mean ± standard deviation: 0.37 ± 0.22 m2g-1), followed by the efficiencies for HULIS (0.14 ± 0.09 m2g-1) and HP-WSOM (0.07 ± 0.05 m2g-1). HULIS was shown to be whiter (more transparent) than that reported from previous studies. WISOM was the predominant light-absorbing OA fraction among three OA fractions. The absorption of solar radiation by the OA fractions relative to that by elemental carbon (f) was analyzed, and it showed an increase with the decrease of polarity: on average, the f values were 12%, 8%, and 2%, for WISOM, HULIS, and HP-WSOM, respectively, for the solar spectrum in a range from 300 to 500 nm. HULIS and WISOM showed noticeable seasonal changes in MAE365, which were higher in winter than in summer. Pearson’s correlation analyses between MAE365 and ion groups of OA fractions indicate that organic compounds with N, O, and S atoms may contribute substantially to the light absorption of OA components.
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- 2022
18. Marine nitrogen fixation as a possible source of atmospheric water-soluble organic nitrogen aerosols in the subtropical North Pacific
- Author
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Tsukasa Dobashi, Yuzo Miyazaki, Eri Tachibana, Kazutaka Takahashi, Sachiko Horii, Yoko Iwamoto, Shu-Kuan Wong, and Koji Hamasaki
- Abstract
Water-soluble organic nitrogen (WSON) in marine atmospheric aerosols affect the water solubility, acidity, and light-absorbing properties of aerosol particles, which are important parameters in assessing both the climate impact and the biogeochemical cycling of bioelements. Size-segregated aerosol and surface seawater (SSW) samples were simultaneously collected over the subtropical North Pacific to investigate the origin of WSON in the marine atmosphere. The fine-mode WSON concentration (7.5 ± 6.6 ngN m−3) at 200–240∘ E along 23∘ N, defined as the eastern North Pacific (ENP), was significantly higher than that (2.4 ± 1.9 ngN m−3) at 135–200∘ E, defined as the western North Pacific (WNP). Analysis of the stable carbon isotope ratio of water-soluble organic carbon (WSOC; δ13CWSOC) together with backward trajectory indicated that most of the observed WSON in the fine particles in the ENP originated from the ocean surface. We found positive relations among nitrogen-fixation rate, dissolved organic nitrogen (DON) in SSW, and the WSON concentrations. The result suggests that reactive nitrogen (DON and ammonium), produced and exuded by nitrogen-fixing microorganisms in SSW, contributed to the formation of WSON aerosols. This study provides new insights into the role of ocean-derived reactive nitrogen aerosols associated with marine microbial activity.
- Published
- 2022
19. New index of organic mass enrichment in sea spray aerosols linked with senescent status in marine phytoplankton
- Author
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Eri Tachibana, Koji Suzuki, Kaori Kawana, Youhei Yamashita, Astrid Müller, Jun Nishioka, and Yuzo Miyazaki
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0301 basic medicine ,010504 meteorology & atmospheric sciences ,lcsh:Medicine ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Phytoplankton ,Atmospheric science ,Organic matter ,lcsh:Science ,Relative species abundance ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Multidisciplinary ,fungi ,lcsh:R ,Biogeochemistry ,Sea spray ,Aerosol ,030104 developmental biology ,chemistry ,Productivity (ecology) ,Chlorophyll ,Environmental chemistry ,Seawater ,lcsh:Q - Abstract
Linking the amount of organic matter (OM) in sea spray aerosols (SSAs) to biological processes in ocean surface is essential for understanding marine aerosol formation and their potential to affect cloud formation. To date, chlorophyll (Chl) a concentration has been widely used as a surrogate for surface phytoplankton biomass or productivity to predict the relative abundance of OM in SSAs (OMSSA). Here we show a new index to present OMSSA using concentrations of Chl a and chlorophyllide (Chllide) a, which is a breakdown product of Chl a and has been used as a biomarker of senescent algal cells. The index was compared with submicrometer OMSSA, based on surface seawater and aerosol samples obtained during the pre-bloom in the western subarctic Pacific. Our results showed that the OMSSA was highly correlated with this unique index, suggesting that the OMSSA was closely linked with senescent algal cells and/or cell lysis. Furthermore, the hygroscopicity parameters κ derived from water-extracted SSA samples implied a reduction in the SSA hygroscopicity with increasing senescent status of phytoplankton. The index can represent OMSSA on a timescale of a day during the pre-bloom period, which should be further examined over different oceanic regions.
- Published
- 2020
20. 13C Probing of Ambient Photo-Fenton Reactions Involving Iron and Oxalic Acid: Implications for Oceanic Biogeochemistry
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Eri Tachibana, Manmohan Sarin, Kimitaka Kawamura, and Srinivas Bikkina
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Atmospheric Science ,Chemistry ,fungi ,Oxalic acid ,Biogeochemistry ,Soluble iron ,Micronutrient ,Southeast asia ,chemistry.chemical_compound ,Space and Planetary Science ,Geochemistry and Petrology ,Abundance (ecology) ,Environmental chemistry ,Phytoplankton ,Biomass burning - Abstract
The atmospheric abundance of oxalic acid significantly influences the supply of soluble iron (Fews), an essential micronutrient for the phytoplankton growth, to the ocean surface. We used the linea...
- Published
- 2020
21. Supplementary material to 'Offline analysis of the chemical composition and hygroscopicity of sub-micrometer aerosol at an Asian outflow receptor site and comparison with online measurements'
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Yange Deng, Hiroaki Fujinari, Hikari Yai, Kojiro Shimada, Yuzo Miyazaki, Eri Tachibana, Dhananjay Deshmukh, Kimitaka Kawamura, Tomoki Nakayama, Shiori Tatsuta, Mingfu Cai, Hanbing Xu, Fei Li, Haobo Tan, Sho Ohata, Yutaka Kondo, Akinori Takami, Shiro Hatakeyama, and Michihiro Mochida
- Published
- 2021
22. Author Correction: New index of organic mass enrichment in sea spray aerosols linked with senescent status in marine phytoplankton
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Kaori Kawana, Koji Suzuki, Youhei Yamashita, Eri Tachibana, Astrid Müller, Yuzo Miyazaki, and Jun Nishioka
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Multidisciplinary ,Index (economics) ,Oceanography ,Science ,Phytoplankton ,Medicine ,Environmental science ,Sea spray ,Author Correction - Abstract
Linking the amount of organic matter (OM) in sea spray aerosols (SSAs) to biological processes in ocean surface is essential for understanding marine aerosol formation and their potential to affect cloud formation. To date, chlorophyll (Chl) a concentration has been widely used as a surrogate for surface phytoplankton biomass or productivity to predict the relative abundance of OM in SSAs (OM
- Published
- 2021
23. Comparison of Surgical Outcomes Between Ab Interno Suture Trabeculotomy and Ab Externo Metal Trabeculotomy in Adult Patients with Glaucoma
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Eri Tachibana, Takanori Matsuoka, Satoshi Matsuda, Yasumasa Otori, Miho Kumoi, and Chieko Tsujino
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medicine.medical_specialty ,Intraocular pressure ,genetic structures ,medicine.medical_treatment ,Glaucoma ,Ocular hypertension ,axial length ,outcomes ,Ophthalmology ,medicine ,Glaucoma surgery ,gonio-assisted transluminal trabeculotomy ,Hyphema ,Original Research ,business.industry ,Proportional hazards model ,Hazard ratio ,MIGS ,Clinical Ophthalmology ,medicine.disease ,Trabeculotomy ,eye diseases ,Surgery ,trabeculotomy ,business ,intraocular pressure - Abstract
Yasumasa Otori, Takanori Matsuoka, Miho Kumoi, Eri Tachibana, Chieko Tsujino, Satoshi Matsuda Department of Ophthalmology, National Hospital Organization, Osaka National Hospital, Osaka, JapanCorrespondence: Yasumasa Otori Email otori.yasumasa.fe@mail.hosp.go.jpPurpose: To compare the outcomes of ab interno suture trabeculotomy (AbI-TLO) and ab externo metal trabeculotomy (AbE-TLO) in adult patients with glaucoma aged over 40 years.Patients and Methods: A retrospective chart review was conducted, including adult patients with glaucoma who underwent AbI-TLO or AbE-TLO between January 2015 and June 2019. A single surgeon (YO) performed all the operations. Eighty-one patients (81 eyes) were included in this study. Surgical success was defined as a postoperative intraocular pressure (IOP) of ⤠18 mmHg and an IOP reduction of ⥠20% from the preoperative IOP, without requiring additional glaucoma surgery. Success rates were assessed using KaplanâMeier survival curves and log-rank (MantelâCox) tests, while risk factors were analyzed using the Cox proportional hazards model.Results: Forty-nine patients who underwent AbI-TLO and 32 patients who underwent AbE-TLO were studied; the preoperative IOPs were 27.9 ± 7.3 (mean ± standard deviation) mmHg and 25.6 ± 8.1 mmHg in the AbI-TLO and AbE-TLO groups, respectively (p=0.217). The 12-month postoperative IOPs were 15.8 ± 4.0 mmHg and 16.3 ± 4.2 mmHg in the AbI-TLO and AbE-TLO groups, respectively (p=0.724). The surgical success rates at 12 months were 77.6% and 62.5% in the AbI-TLO and AbE-TLO groups, respectively (p=0.144). Postoperative hyphema with level formation and ocular hypertension over 30 mmHg were observed in 22.4% and 26.5% of patients in the AbI-TLO group and 18.8% and 12.5% of those in the AbE-TLO group, respectively. Stepwise multivariate Cox regression analysis showed that a longer axial length was a risk factor for surgical failure (hazard ratio: 2.030; p=0.042).Conclusion: AbI-TLO and AbE-TLO had similar surgical outcomes and postoperative complications. A longer axial length was associated with an insufficient IOP reduction.Keywords: axial length, gonio-assisted transluminal trabeculotomy, intraocular pressure, MIGS, outcomes, trabeculotomy
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- 2021
24. Fluorescence property of solvent extractable organic aerosol in a cold-temperate forest area of Japan
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Yuzo Miyazaki, Kimitaka Kawamura, Eri Tachibana, Michihiro Mochida, Dhananjay K. Deshmukh, and Sonia Afsana
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Solvent ,Environmental chemistry ,Environmental science ,Temperate forest ,Fluorescence ,Aerosol - Abstract
Organic aerosol (OA), a major component of atmospheric aerosol, is considered to be one of the key players in atmospheric radiative balance and climate change. Chromophoric OA, termed as brown carbon (BrC), is a component that can absorb solar radiation in the ultraviolet and short-wavelength visible regions and is composed of a wide range of poorly characterized compounds. Whereas light absorption properties were analyzed to characterize chromophoric OA, fluorescent properties also provide information on them. In this study, the fluorescence property of solvent extractable organics in submicron aerosol particles collected in a forest in the cool-temperate zone of northern Japan, was characterized.Aerosol samples were collected on quartz filters (cut-off diameter: ≤0.95 micrometer) in Tomakomai Experimental Forest of Hokkaido University. Organic aerosol components in the samples were extracted and fractionated on the basis of their polarity by the combination of solvent extraction and solid-phase extraction methods. Water-soluble organic matter (WSOM) and water-insoluble organic matter (WISOM) were extracted sequentially by using multiple solvents. Two fractions, humic-like substance (HULIS) and highly-polar water-soluble organic matter (HP-WSOM), were fractionated from WSOM by solid phase extraction. The excitation−emission matrices (EEMs) were measured using a fluorescence spectrometer, and the fluorescence property of the extracts was characterized by the classification of EEM profiles using a Parallel Factor (PARAFAC) model.From the PARAFAC analysis, five types of fluorescent components were identified for each of WSOM and WISOM fractions. A fluorescence component with the characteristics reported to be associated with (HULIS) accounted for large fractions of the fluorescence from WSOM and WISOM (mean: 68% and 84%, respectively). The relative contribution of the fluorescent components for WSOM shows a clear seasonal variation of the characteristics of WSOM. Furthermore, from each of HULIS and HP-WSOM fractions, five types of fluorescent components were identified. Fluorescence components with the characteristics of protein-like compounds identified in previous EEM studies accounted for a large fraction of the fluorescence from HP-WSOM (mean: 53%), whereas the contribution of protein-like compounds was smaller in the case of the HULIS fraction (mean: 23%).
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- 2021
25. Role of Oxalic acid on Fractional Solubility of Aerosol Iron over Coastal Ocean: Evidence from compound-specific stable carbon isotopic composition and diagnostic mass ratios
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Srinivas Bikkina, Eri Tachibana, Manmohan Sarin, and Kimitaka Kawamura
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chemistry.chemical_compound ,chemistry ,Compound specific ,Environmental chemistry ,Oxalic acid ,chemistry.chemical_element ,Solubility ,Carbon ,Isotopic composition ,Aerosol - Abstract
Atmospheric transport and the subsequent air-to-sea deposition of water-soluble iron (Fews), an essential micronutrient for the phytoplankton growth, have a profound influence on the biogeochemical cycles of carbon and nitrogen. Sources of Fews include contributions from poorly soluble natural mineral dust and highly soluble anthropogenic aerosols from biomass burning emissions and fossil-fuel combustion in the continental outflows. Apart from the source/emission contributions, atmospheric processing of aerosol iron (FeTot) by inorganic acidic species (e.g., non-sea-salt or nss-SO42- and NO3-) and/or organic acids also affect the supply of Fews to the surface waters that are downwind of pollution sources. Among these, the least understood process is the oxalic acid-mediated photochemical cycling of Fews. Laboratory studies have clearly demonstrated an enhancement in the fractional solubility of aerosol iron (i.e., Fews (%) = Fews/FeTot ×100) via the oxalic acid complexation with FeTot and subsequent photochemical reduction process. However, lacking support from the field measurements limits our ability to incorporate the proposed mechanism in the current biogeochemistry models. This study is designed with the overarching goal of investigating the role of oxalic acid on the Fews (%) over a coastal ocean (i.e., the Bay of Bengal: BoB) influenced by the atmospheric outflow from the Indo-Gangetic Plain (IGP) and South-east Asia (SEA) during the winter season. We analysed 31 PM2.5 samples for the mass concentrations of FeTot, Fews and other chemical composition including nss-SO42-, NO3-, oxalic acid and related polar compounds as well as stable carbon isotopic composition of oxalic acid (δ13Coxalic). Strong positive linear relationship of oxalic acid with FeTot and significant inverse linear relationship between δ13Coxalic and Fews over the BoB clearly emphasize the role of oxalic acid on the Fews (%). These findings comply with the notion that oxalic acid formed from the precursor water-soluble organic acids in the deliquescent aerosols, is complexed with aerosol-Fe and undergoes through successive photochemical reactions, contributing to an overall increase in the Fews (%).
- Published
- 2020
26. Aerosol Liquid Water Promotes the Formation of Water-Soluble Organic Nitrogen in Submicrometer Aerosols in a Suburban Forest
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Yuzo Miyazaki, Sathiyamurthi Ramasamy, Kazuhide Matsuda, Yu Xu, Yasuhiro Sadanaga, Eri Tachibana, Yosuke Sakamoto, Tomoki Mochizuki, Yoshihiro Nakashima, Yoshizumi Kajii, and Kei Sato
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Aerosols ,Biogeochemical cycle ,Air Pollutants ,Volatile Organic Compounds ,Chemical substance ,Liquid water ,Nitrogen ,chemistry.chemical_element ,Water ,General Chemistry ,010501 environmental sciences ,Forests ,01 natural sciences ,Aerosol ,Water soluble ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Environmental science ,0105 earth and related environmental sciences - Abstract
Water-soluble organic nitrogen (WSON) affects the formation, chemical transformations, hygroscopicity, and acidity of organic aerosols as well as biogeochemical cycles of nitrogen. However, large uncertainties exist in the origins and formation processes of WSON. Submicrometer aerosol particles were collected at a suburban forest site in Tokyo in summer 2015 to investigate the relative impacts of anthropogenic and biogenic sources on WSON formations and their linkages with aerosol liquid water (ALW). The concentrations of WSON (ave. 225 ± 100 ngN m
- Published
- 2020
27. Smoke aerosol chemistry and aging of Siberian biomass burning emissions in a large aerosol chamber
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Guenter Engling, Evangelia Diapouli, Konstantinos Eleftheriadis, Kaori Ono, Olga Popovicheva, Athina-Cerise Kalogridis, Eri Tachibana, V. S. Kozlov, and Kimitaka Kawamura
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Smoke ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Chemistry ,Levoglucosan ,Biomass ,chemistry.chemical_element ,010501 environmental sciences ,Particulates ,Combustion ,complex mixtures ,01 natural sciences ,Aerosol ,chemistry.chemical_compound ,Deposition (aerosol physics) ,Environmental chemistry ,Carbon ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Vegetation open fires constitute a significant source of particulate pollutants on a global scale and play an important role in both atmospheric chemistry and climate change. To better understand the emission and aging characteristics of smoke aerosols, we performed small-scale fire experiments using the Large Aerosol Chamber (LAC, 1800 m3) with a focus on biomass burning from Siberian boreal coniferous forests. A series of burn experiments were conducted with typical Siberian biomass (pine and debris), simulating separately different combustion conditions, namely, flaming, smoldering and mixed phase. Following smoke emission and dispersion in the combustion chamber, we investigated aging of aerosols under dark conditions. Here, we present experimental data on emission factors of total, elemental and organic carbon, as well as individual organic compounds, such as anhydrosugars, phenolic and dicarboxylic acids. We found that total carbon accounts for up to 80% of the fine mode (PM2.5) smoke aerosol. Higher PM2.5 emission factors were observed in the smoldering compared to flaming phase and in pine compared to debris smoldering phase. For low-temperature combustion, organic carbon (OC) contributed to more than 90% of total carbon, whereas elemental carbon (EC) dominated the aerosol composition in flaming burns with a 60–70% contribution to the total carbon mass. For all smoldering burns, levoglucosan (LG), a cellulose decomposition product, was the most abundant organic species (average LG/OC = 0.26 for pine smoldering), followed by its isomer mannosan or dehydroabietic acid (DA), an important constituent of conifer resin (DA/OC = 0.033). A levoglucosan-to-mannosan ratio of about 3 was observed, which is consistent with ratios reported for coniferous biomass and more generally softwood. The rates of aerosol removal for OC and individual organic compounds were investigated during aging in the chamber in terms of mass concentration loss rates over time under dark conditions and compared to the loss rate of EC. The latter is used as an inert tracer for estimating aerosol mechanical deposition and wall losses of the otherwise chemically conserved aerosol species. The OC/EC ratio increased with smoke aging for the flaming phase, suggesting a production/partitioning of organic compounds after emission. On the other hand, for smoldering burns OC/EC ratios decreased further with aging due to additional sinks of OC, other than those related to deposition and wall losses alone, such as evaporation of semi-volatile compounds. The chemical fingerprints of the major PM components of fresh and aged smoke found in this study are proposed to be used for the assessment of contributions from Siberian biomass burning to atmospheric pollution in source apportionment studies like those using molecular marker approaches.
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- 2018
28. Evidence of a reduction in cloud condensation nuclei activity of water-soluble aerosols caused by biogenic emissions in a cool-temperate forest
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Eri Tachibana, Yuzo Miyazaki, Tsutom Hiura, Kimitaka Kawamura, and Astrid Müller
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Forest floor ,chemistry.chemical_classification ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Ecology ,Science ,Climate change ,Temperate forest ,010501 environmental sciences ,01 natural sciences ,Article ,Aerosol ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Litter ,Environmental science ,Cloud condensation nuclei ,Medicine ,Organic matter ,Sulfate ,0105 earth and related environmental sciences - Abstract
Biogenic organic aerosols can affect cloud condensation nuclei (CCN) properties, and subsequently impact climate change. Large uncertainties exist in how the difference in the types of terrestrial biogenic sources and the abundance of organics relative to sulfate affect CCN properties. For the submicron water-soluble aerosols collected for two years in a cool-temperate forest in northern Japan, we show that the hygroscopicity parameter κCCN (0.44 ± 0.07) exhibited a distinct seasonal trend with a minimum in autumn (κCCN = 0.32–0.37); these κCCN values were generally larger than that of ambient particles, including water-insoluble fractions. The temporal variability of κCCN was controlled by the water-soluble organic matter (WSOM)-to-sulfate ratio (R2 > 0.60), where the significant reduction of κCCN in autumn was linked to the increased WSOM/sulfate ratio. Positive matrix factorization analysis indicates that α-pinene-derived secondary organic aerosol (SOA) substantially contributed to the WSOM mass (~75%) in autumn, the majority of which was attributable to emissions from litter/soil microbial activity near the forest floor. These findings suggest that WSOM, most likely α-pinene SOA, originated from the forest floor can significantly suppress the aerosol CCN activity in cool-temperate forests, which have implications for predicting climate effects by changes in biogenic emissions in future.
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- 2017
29. Alpine snowpit profiles of polar organic compounds from Mt. Tateyama central Japan: Atmospheric transport of organic pollutants with Asian dust
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Ambarish Pokhrel, Eri Tachibana, Bhagawati Kunwar, Kimitaka Kawamura, and Kazuma Aoki
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Pollutant ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Asian Dust ,Oxalic acid ,010501 environmental sciences ,Snow ,01 natural sciences ,Troposphere ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Loess ,human activities ,Chemical composition ,Isoprene ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Snowpit samples (n = 10) were collected (19 April 2008) from the snowpit sequences (depth 6.60 m) at the Murodo-Daira site (36.58°N, 137.60°E, elevation of 2450 m a.s.l.) of Mt. Tateyama (3015 m a.s.l.), central Japan. The first time, low molecular weight diacids, ω-oxoacids, pyruvic acid, and α-dicarbonyls were measured for this snowpit sequence. Higher concentrations of short-chain diacids (C2–C5) are observed in dusty snow than non-dusty snow samples. Longer chain diacids (C7–C12) are significant in granular and dusty snow samples. Aromatic and aliphatic unsaturated diacids showed higher concentrations in the slightly dusty layer deposited in winter. Except for a clean layer, molecular distributions of diacids are characterized by the predominance of oxalic acid (C2, ave, 20 ± 22 ng/g-snow) followed by succinic (C4, 7.2 ± 5.9 ng/g -snow), and malonic acids (C3, 3.3 ± 2.9 ng/g -snow) for all the snow layers. Lower C3/C4 ratios (0.46) suggest that organic aerosols are rather fresh without serious photochemical aging during the long-range transport over central Japan. The higher concentrations of the secondary species in dusty snow than non-dusty samples were mainly attributed to the heterogeneous reaction. The strong correlations of incloud oxidation products of isoprene, aromatic acids, and fatty acids suggest that condensation, oxidation, and photolysis are important reaction mechanisms for the formation of diacids. Chinese Loess (Kosa particles) and Mongolian Gobi desert's dust provided the surface area for polar organic compounds, traveled to several thousand kilometers in the lower troposphere, and snow metamorphism altered the chemical composition of diacids and related compounds.
- Published
- 2021
30. Subarachnoid hemorrhage-negative Terson syndrome after intracranial artery treatment with a flow diverter device
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Seiyo Harino, Yasumasa Otori, Satoshi Matsuda, Kumiko Kazuo, Junko Yokoyama, Miho Kumoi, Eri Tachibana, Chieko Tsujino, and Takanori Matsuoka
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medicine.medical_specialty ,Subarachnoid hemorrhage ,genetic structures ,Case Report ,Vascular occlusion ,03 medical and health sciences ,0302 clinical medicine ,Aneurysm ,lcsh:Ophthalmology ,medicine ,cardiovascular diseases ,Vitreous hemorrhage ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,Intracranial Artery ,Terson syndrome ,medicine.disease ,Fluorescein angiography ,Sub-inner limiting membrane hemorrhage ,eye diseases ,Flow diverter ,Ophthalmology ,lcsh:RE1-994 ,030221 ophthalmology & optometry ,Subarachnoid hemorrhage-negative terson syndrome ,sense organs ,Radiology ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Purpose To report a case of subarachnoid hemorrhage-negative Terson syndrome following intracranial artery treatment with flow diverter stents. Observations A 40-year-old Asian woman presented with floaters in her right eye after treatment of an intracranial aneurysm with flow diverter stents. Vitreous hemorrhage and sub-inner limiting membrane (sub-ILM) hemorrhage were present in her right eye. On fluorescein angiography, contrast perfusion and vascular occlusion were not noted. Magnetic resonance imaging (MRI) did not show any evidence of subarachnoid hemorrhage (SAH). We hypothesize that the bleeding was due to Terson syndrome associated with intracranial treatment with the flow diverter stents. During follow-up, the vitreous hemorrhage and sub-ILM hemorrhage disappeared, and the floaters in her vision improved. Conclusions and Importance This is the first reported case of vitreous hemorrhage and sub-ILM hemorrhage that should be considered to be Terson syndrome, after flow diverter stents treatment in the absence of SAH.
- Published
- 2020
31. Identification of hydroxy- and keto-dicarboxylic acids in remote marine aerosols using gas chromatography/quadruple and time-of-flight mass spectrometry
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Divyavani Gowda, Eri Tachibana, and Kimitaka Kawamura
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Tartronic acid ,Chromatography ,010504 meteorology & atmospheric sciences ,Trimethylsilyl ,Organic Chemistry ,010501 environmental sciences ,BSTFA ,Mass spectrometry ,01 natural sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Organic chemistry ,Gas chromatography ,Time-of-flight mass spectrometry ,Derivatization ,Spectroscopy ,0105 earth and related environmental sciences ,Mass spectral interpretation - Abstract
Rationale The identification of hydroxy- and keto-dicarboxylic acids (diacids) in remote marine aerosol samples is important for a better understanding of the composition of organic particulate matter, as this chemical composition is essential for predicting the effects on climate, air quality, and human health. Molecular characterization of these compounds provides insights into sources and formation pathways of organic aerosols. Methods The method of chemical derivatization followed by gas chromatography–flame ionization detection (GC-FID), gas chromatography/quadruple mass spectrometry (GC/QMS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) was used to identify hydroxy- and keto-diacids in remote marine aerosols. Atmospheric samples were collected at Chichijima Island in the western North Pacific and the diacids and related compounds were extracted with organic-free ultrapure water. A two-step derivatization technique was employed, using 14% BF3/n-butanol for the butylation of carboxyl groups and acidic ketones followed by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) for the trimethylsilylation of hydroxyl groups. Results Several new peaks were detected in the gas chromatogram after trimethylsilylation of the dibutyl ester fraction. Based on mass spectral interpretation with authentic standards, we successfully identified and quantified a homologous series of hydroxydiacids, including tartaric and oxaloacetic acids. In addition, transformation of oxaloacetic acid into its enol form was elucidated. Conclusions Utilizing GC-FID, GC/QMS and GC/TOFMS, hydroxy- and keto-diacids were identified in the remote marine aerosols. A complete structural characterization was achieved with extensive mass spectral analysis. Molecular distributions of hydroxydiacids generally showed the predominance of malic acid followed by tartronic acid. We consider that these hydroxydiacids are important intermediates in the atmospheric oxidation of organic aerosols to result in smaller diacids. Copyright © 2016 John Wiley & Sons, Ltd.
- Published
- 2016
32. A sub-decadal trend in diacids in atmospheric aerosols in eastern Asia
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Eri Tachibana, Jinsang Jung, Pingqing Fu, Shuvashish Kundu, Kimitaka Kawamura, Myeongwon Lee, and M. Kobayashi
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Pollution ,chemistry.chemical_classification ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,Levoglucosan ,010501 environmental sciences ,01 natural sciences ,lcsh:QC1-999 ,Aerosol ,Atmosphere ,lcsh:Chemistry ,chemistry.chemical_compound ,chemistry ,Nitrate ,lcsh:QD1-999 ,Environmental chemistry ,Climatology ,Environmental science ,Sulfate ,Air mass ,lcsh:Physics ,0105 earth and related environmental sciences ,media_common ,Organic acid - Abstract
Change in secondary organic aerosols (SOAs) has been predicted to be highly uncertain in the future atmosphere in Asia. To better quantify the SOA change, we examine the sub-decadal (2001–2008) trend in major surrogate compounds (C2–C10 diacids) of SOA in atmospheric aerosols from Gosan site on Cheju Island, South Korea. The Gosan site is influenced by pollution outflows from eastern Asia. The molecular distributions of diacids were characterized by the predominance of oxalic (C2) acid followed by malonic (C3) and succinic (C4) acids in each year. The seasonal variations in diacids in each year were characterized by the highest concentrations of saturated diacids in spring and unsaturated diacids in winter. The consistent molecular distributions and seasonal variations along with significantly similar air mass transport patterns are indicative of similar pollution sources for diacids in eastern Asia on a sub-decadal scale. However, the intensity of the pollution sources has increased as evidenced by the increases in major diacids at the rate of 3.9–47.4 % per year, particularly in April. The temporal variations in atmospheric tracer compounds (carbon monoxide, levoglucosan, 2-methyltetrols, pinic acid, glyoxylic acid, glyoxal and methylglyoxal) suggest that the increases in diacids are due to enhanced precursor emissions associated with more anthropogenic than biogenic activities followed by the compounds' chemical processing in the atmosphere. The trends in diacids contrast with the reported decreases in sulfate, nitrate and ammonium in recent years in eastern Asia. This study demonstrates that recent pollution control strategies in eastern Asia were not able to decrease organic acidic species in the atmosphere. The increases in water-soluble organic acid fraction could modify the aerosol organic composition and its sensitivity to climate relevant physical properties.
- Published
- 2016
33. Impact of biogenic emissions of organic matter from a cool-temperate forest on aerosol optical properties
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Yuzo Miyazaki, Kazuma Aoki, Tsutom Hiura, Eri Tachibana, and Astrid Müller
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chemistry.chemical_classification ,Canopy ,Forest floor ,Atmospheric Science ,Angstrom exponent ,Tree canopy ,010504 meteorology & atmospheric sciences ,Single-scattering albedo ,Aerosol optical properties ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,Water-soluble aerosols ,Aerosol ,chemistry.chemical_compound ,Biogenic secondary organic aerosols ,chemistry ,Environmental science ,Organic matter ,Sulfate ,Sky radiometer ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Terrestrial biogenic emissions of organic matter can affect the optical properties of atmospheric aerosols and thus impact the radiation budget. To investigate this, the chemical parameters of submicrometer water-soluble aerosols (WSA) collected on filters were compared to optical properties measured by a sky radiometer at a cool-temperate forest site in northern Japan. From June to December 2015, the WSA samples were collected within the forest canopy, while aerosol optical depth (AOD), single scattering albedo (SSA), absorption Angstrom exponent (AAE), and scattering Angstrom exponent (SAE) were retrieved above the canopy. The optical properties were compared with the filter-based chemical parameters only when the vertical transport of aerosol particles from the forest canopy to the air above it was significant. The result showed that the AOD and the mass concentrations of WSA exhibited similar and distinct seasonal variations with peaks in summer and autumn. In summer, sulfate accounted for 60% of the mass of WSA, which was linked to a high SSA (>0.95), low AAE (1.15 ± 0.84), and low SAE (1.25 ± 0.22). In contrast, water-soluble organic matter (WSOM) accounted for 70% of the mass of WSA in autumn. This large fraction of WSOM was associated with a decrease in SSA (0.90–0.95) and an increase in AAE (2.45 ± 0.91) and SAE (1.46 ± 0.15). The results suggest that in summer, aerosol particles with a greater size range corresponded to aerosol chemical compositions dominated by sulfate. In contrast, smaller particles with a strong light absorption at shorter wavelengths, were likely important in autumn and associated with a composition dominated by WSOM. The majority of WSOM in autumn has previously been associated with emissions of α-pinene from the forest floor and the subsequent formation of biogenic secondary organic aerosols (BSOA). This study indicates that α-pinene-derived SOAs, mostly originating from the forest floor, were associated with a summer to autumn decrease in SSA. This process can modulate the radiative effect on a regional scale.
- Published
- 2020
34. Dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid in PM2.5 aerosol collected during CAREBeijing-2007: an effect of traffic restriction on air quality
- Author
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Ru-Jin Huang, L. Tian, Shuncheng Lee, Tong Zhu, Kin Fai Ho, Eri Tachibana, Steven Sai Hang Ho, and Kimitaka Kawamura
- Subjects
chemistry.chemical_classification ,Pollutant ,Pollution ,Atmospheric Science ,Meteorology ,media_common.quotation_subject ,Air pollution ,medicine.disease_cause ,lcsh:QC1-999 ,Aerosol ,lcsh:Chemistry ,Phthalic acid ,chemistry.chemical_compound ,Dicarboxylic acid ,lcsh:QD1-999 ,chemistry ,Beijing ,Environmental chemistry ,medicine ,Environmental science ,Air quality index ,lcsh:Physics ,media_common - Abstract
Thirty water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid were determined as well as organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) in PM2.5 samples collected during the Campaign of Air Quality Research in Beijing 2007 (CAREBeijing-2007) in the urban and suburban areas of Beijing. The objective of this study is to identify the influence of traffic emissions and regional transport to the atmosphere in Beijing during summer. PM2.5 samples collected with or without traffic restriction in Beijing are selected to evaluate the effectiveness of local traffic restriction measures on air pollution reduction. The average concentrations of the total quantified bifunctional organic compounds (TQBOCs), total fatty acids and benzoic acid during the entire sampling period were 1184±241, 597±159 and 1496±511 ng m−3 in Peking University (PKU), and 1050±303, 475±114 and 1278±372 ng m−3 in Yufa, Beijing. Oxalic acid (C2) was found as the most abundant dicarboxylic acid at PKU and Yufa followed by phthalic acid (Ph). A strong even carbon number predominance with the highest level at stearic acid (C18:0), followed by palmitic acid (C16:0) was found for fatty acids. According to the back trajectories modeling results, the air masses were found to originate mainly from the northeast, passing over the southeast or south of Beijing (heavily populated, urbanized and industrialized areas), during heavier pollution events, whereas they are mainly from the north or northwest sector (mountain areas without serious anthropogenic pollution sources) during less pollution events. The data with wind only from the same sector (minimizing the difference from regional contribution) but with and without traffic restriction in Beijing were analyzed to evaluate the effectiveness of local traffic restriction measures on the reduction of local air pollution in Beijing. The results suggested that the traffic restriction measures can reduce the air pollutants, but the decrease of pollutants is generally smaller in Yufa compared to that in PKU. Moreover, an enhancement of EC value indicates more elevated primary emissions in Yufa during restriction periods than in non-restriction periods. This study demonstrates that even when primary exhaust was controlled by traffic restriction, the contribution of secondary organic species formed from photochemical processes was critical with long-range atmospheric transport of pollutants.
- Published
- 2015
35. Seasonal cycles of water-soluble organic nitrogen aerosols in a deciduous broadleaf forest in northern Japan
- Author
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Eri Tachibana, Pingqing Fu, Kimitaka Kawamura, Kaori Ono, and Yuzo Miyazaki
- Subjects
Canopy ,Forest floor ,Atmospheric Science ,Tree canopy ,Range (biology) ,forest environment ,chemistry.chemical_element ,biogenic organic aerosol ,water-soluble organic nitrogen ,Particulates ,Nitrogen ,Aerosol ,Geophysics ,Deciduous ,chemistry ,Space and Planetary Science ,Climatology ,Environmental chemistry ,Earth and Planetary Sciences (miscellaneous) ,Environmental science - Abstract
The seasonal variations in aerosol water-soluble organic nitrogen (WSON) concentrations measured in a deciduous forest canopy over an approximately 30 month period were investigated for possible sources in the forest. The WSON concentrations (average 157 ± 127 ng N m−3) and WSON/water-soluble total nitrogen mass fractions (average 20 ± 11%) in the total suspended particulate matter exhibited a clear seasonal cycle with maxima in early summer. The WSON mass was found to reside mostly in the fine-mode size range (Dp 1.9 µm), which was similar to the size distributions of sugar compounds, indicating that the major WSON sources in autumn are associated with primary biological emissions. The vertical differences in WSON concentrations suggest that the water-soluble organic aerosol is enriched with nitrogen below the canopy level relative to the forest floor. The WSON concentration increased with enhanced hydrogen ion concentrations in aerosol in the early summer, indicating that aerosol acidity associated with anthropogenic sources outside the forest likely plays an important role in the formation of WSON in that season. The study suggests that multiple sources of WSON within the forest canopy may dominate over others in specific seasons, providing insights into WSON formation processes in forest environments.
- Published
- 2014
36. Large contribution of fine carbonaceous aerosols from municipal waste burning inferred from distributions of diacids and fatty acids
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N He, Pingqing Fu, X Li, Chandra Mouli Pavuluri, Eri Tachibana, Z Yang, and Kimitaka Kawamura
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Total organic carbon ,Atmospheric Science ,Municipal solid waste ,Chemistry ,Oxalic acid ,Geology ,Inorganic ions ,Agricultural and Biological Sciences (miscellaneous) ,Aerosol ,Atmosphere ,chemistry.chemical_compound ,Environmental chemistry ,Biomass burning ,Air quality index ,Earth-Surface Processes ,General Environmental Science ,Food Science - Abstract
To investigate the origins, other than fossil fuel combustion and biomass burning, of urban carbonaceosus aerosols, we studied the fine (PM2.5) aerosols collected in Guiyang, Southwest China in winter (December 10–23) 2012 for organic carbon (OC), elemental carbon (EC) and water-soluble diacids, oxoacids, α-dicarbonyls and fatty acids as well as inorganic ions. Oxalic acid (C2) found to be the most abundant diacid species followed by succinic (C4) and terephthalic (t-Ph) acids, respectively. Even-carbon numbered fatty acids showed high abundances with a peak at C16. OC, EC and most of diacids and related compounds, but not inorganic ions, showed a similar temporal pattern with a drastic rise in December 15 day- and night-time samples during the campaign. Based on molecular distributions of diacids and fatty acids, and linear relations of OC and EC with selected marker ions and diacid species, we found that the organics and EC in PM2.5 are mainly derived from higher plant/cooking and municipal waste burning emissions in Guiyang. This study implies that municipal waste burning largely contributes to carbonaceous aerosols and warrants a need of further research on its role in aerosol loading and air quality in the urban atmosphere.
- Published
- 2019
37. High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and alpha-dicarbonyls in the mountaintop aerosols over the North China Plain during wheat burning season
- Author
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Yugo Kanaya, K. Okuzawa, Kimitaka Kawamura, Z. F. Wang, Shankar G. Aggarwal, and Eri Tachibana
- Subjects
Total organic carbon ,Atmospheric Science ,Ozonolysis ,Straw ,lcsh:QC1-999 ,Aerosol ,lcsh:Chemistry ,chemistry.chemical_compound ,chemistry ,lcsh:QD1-999 ,Environmental chemistry ,Glyoxal ,Organic chemistry ,Pyruvic acid ,Gas chromatography ,Glyoxylic acid ,lcsh:Physics - 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. Molecular distributions of 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) acids, were also detected together with aromatic diacids (phthalic, isophthalic and terephthalic 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 the period 8–11 June, when the wind direction shifted from southerly 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 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 as well as dark ozonolysis of volatile organic compounds and other organics, accretion reactions and oxidation of nonvolatile organics such as unsaturated fatty acids. 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.
- Published
- 2013
38. Low molecular weight (C1-C10) monocarboxylic acids, dissolved organic carbon and major inorganic ions in alpine snow pit sequence from a high mountain site, central Japan
- Author
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Kimitaka Kawamura, Eri Tachibana, Kohei Matsumoto, and Kazuma Aoki
- Subjects
Atmospheric Science ,Aromatic acid ,Chemistry ,Formic acid ,High mountain snowpack ,Inorganic chemistry ,Nonanoic acid ,Lactic acid ,Asian dust ,Inorganic ions ,Acetic acid ,Propionic acid ,Sulfate ,chemistry.chemical_compound ,Glycolic acid ,Environmental chemistry ,Dissolved organic carbon ,Calcium ,General Environmental Science ,Benzoic acid - Abstract
Snowpack samples were collected from a snow pit sequence (6 m in depth) at the Murodo-Daira site near the summit of Mt. Tateyama, central Japan, an outflow region of Asian dusts. The snow samples were analyzed for a homologous series of low molecular weight normal (C1–C10) and branched (iC4–iC6) monocarboxylic acids as well as aromatic (benzoic) and hydroxy (glycolic and lactic) acids, together with major inorganic ions and dissolved organic carbon (DOC). The molecular distributions of organic acids were characterized by a predominance of acetic (range 7.8–76.4 ng g−1-snow, av. 34.8 ng g−1) or formic acid (2.6–48.1 ng g−1, 27.7 ng g−1), followed by propionic acid (0.6–5.2 ng g−1, 2.8 ng g−1). Concentrations of normal organic acids generally decreased with an increase in carbon chain length, although nonanoic acid (C9) showed a maximum in the range of C5–C10. Higher concentrations were found in the snowpack samples containing dust layer. Benzoic acid (0.18–4.1 ng g−1, 1.4 ng g−1) showed positive correlation with nitrate (r = 0.70), sulfate (0.67), Na+ (0.78), Ca2+ (0.86) and Mg+ (0.75), suggesting that this aromatic acid is involved with anthropogenic sources and Asian dusts. Higher concentrations of Ca2+ and SO42− were found in the dusty snow samples. We found a weak positive correlation (r = 0.43) between formic acid and Ca2+, suggesting that gaseous formic acid may react with Asian dusts in the atmosphere during long-range transport. However, acetic acid did not show any positive correlations with major inorganic ions. Hydroxyacids (0.03–5.7 ng g−1, 1.5 ng g−1) were more abundant in the granular and dusty snow. Total monocarboxylic acids (16–130 ng g−1, 74 ng g−1) were found to account for 1–6% of DOC (270–1500 ng g−1, 630 ng g−1) in the snow samples.
- Published
- 2012
39. Time-resolved variations in the distributions of inorganic ions, carbonaceous components, dicarboxylic acids and related compounds in atmospheric aerosols from Sapporo, northern Japan during summertime
- Author
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Kimitaka Kawamura, Chandra Mouli Pavuluri, Shankar G. Aggarwal, Eri Tachibana, and Motomi Kikuta
- Subjects
Ketoacids ,Total organic carbon ,Atmospheric Science ,WSOC ,Chemistry ,Inorganic chemistry ,Inorganic ions ,Time-resolved variation ,α dicarbonyls ,Aerosol ,Atmosphere ,α-Dicarbonyls ,Long-range transport ,Dicarboxylic acids ,Elemental carbon ,Biomass burning ,Organic carbon ,General Environmental Science - Abstract
To better understand time-resolved variations of water-soluble organic aerosols in the atmosphere, we collected atmospheric particles (TSP) every 3 h during summertime (8–10 August, 2005) in Sapporo, northern Japan. We measured inorganic ions, carbonaceous components, dicarboxylic acids, ketoacids and α-dicarbonyls in TSP. SO42− was found as the most abundant ionic species (57 ± 9% of total ions determined) followed by NH4+ and NO3−. However, none of the ionic species showed any diurnal trend throughout the campaign. Organic carbon (OC) ranged from 2.1 to 12.1 μg m−3 whereas elemental carbon (EC) was negligible in most of the samples (0.31 ± 0.56 μg m−3). Oxalic (C2) acid was the most abundant diacid species, followed by malonic (C3) and succinic (C4) acids. Water-soluble OC (WSOC), water-insoluble OC (WIOC) and OC as well as dominant diacids (C2–C4), total diacids, ketoacids and α-dicarbonyls did not show diurnal trend on 8 August, but they showed clear diurnal distributions during 9–10 August following the changes in ambient temperature (and radiation). Detailed analyses of time-resolved aerosols demonstrate that diurnal variations of organic aerosol compositions are caused by local in situ photochemical production, but are significantly superimposed by long-range atmospheric transport of aerosols, particularly when the air masses are enriched with emissions from higher plants and/or biomass burning, and their photochemical processing during the transport.
- Published
- 2012
40. Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer
- Author
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Richard Sempéré, Bruno Charrière, Eri Tachibana, Kaori Ono, Kimitaka Kawamura, Institute of Low-Temperature Science, Hokkaido University [Sapporo, Japan], Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010504 meteorology & atmospheric sciences ,Oxalic acid ,lcsh:Life ,010501 environmental sciences ,α dicarbonyls ,01 natural sciences ,Late summer ,Atmosphere ,chemistry.chemical_compound ,lcsh:QH540-549.5 ,Sea ice ,14. Life underwater ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,geography ,geography.geographical_feature_category ,lcsh:QE1-996.5 ,The arctic ,lcsh:Geology ,lcsh:QH501-531 ,Oceanography ,chemistry ,Arctic ,13. Climate action ,Environmental chemistry ,lcsh:Ecology - 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.
- Published
- 2012
41. Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning
- Author
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Yele Sun, Eri Tachibana, Jiule Li, Shankar G. Aggarwal, K. Okuzawa, Kimitaka Kawamura, Yugo Kanaya, Hiroshi Tanimoto, Jing Chen, Pingqing Fu, Y. Liu, and Z. F. Wang
- Subjects
Total organic carbon ,chemistry.chemical_classification ,Atmospheric Science ,Chemistry ,Levoglucosan ,chemistry.chemical_element ,Particulates ,Organic compound ,lcsh:QC1-999 ,Aerosol ,Organic molecular tracers ,lcsh:Chemistry ,chemistry.chemical_compound ,lcsh:QD1-999 ,Isotopes of carbon ,Environmental chemistry ,Carbon ,lcsh:Physics - Abstract
Organic tracer compounds, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios (δ13C) of total carbon (TC) have been investigated in aerosol samples collected during early and late periods of the Mount Tai eXperiment 2006 (MTX2006) field campaign in the North China Plain. Total solvent-extractable fractions were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA) tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs). In early June when the field burning activities of wheat straws in the North China Plain were very active, the total identified organics (2090 ± 1170 ng m−3) were double those in late June (926 ± 574 ng m−3). All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88–1210 ng m−3, mean 403 ng m−3) was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude, which could be further transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 24% (up to 64%) of the OC in the Mt. Tai aerosols was due to biomass burning in early June, followed by the contribution of isoprene SOC (mean 4.3%). In contrast, isoprene SOC was the main contributor (6.6%) to OC, and only 3.0% of the OC was due to biomass burning in late June. In early June, δ13C of TC (−26.6 to −23.2‰, mean −25.0‰) were lower than those (−23.9 to −21.9‰, mean −22.9‰) in late June. In addition, a strong anti-correlation was found between levoglucosan and δ13C values. This study demonstrates that crop-residue burning activities can significantly enhance the organic aerosol loading and alter the organic composition and stable carbon isotopic composition of aerosol particles in the troposphere over the North China Plain.
- Published
- 2012
42. Identification of hydroxy- and keto-dicarboxylic acids in remote marine aerosols using gas chromatography/quadruple and time-of-flight mass spectrometry
- Author
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Divyavani, Gowda, Kimitaka, Kawamura, and Eri, Tachibana
- Subjects
Dicarboxylic Acids ,Particulate Matter ,Hydroxy Acids ,Gas Chromatography-Mass Spectrometry - Abstract
The identification of hydroxy- and keto-dicarboxylic acids (diacids) in remote marine aerosol samples is important for a better understanding of the composition of organic particulate matter, as this chemical composition is essential for predicting the effects on climate, air quality, and human health. Molecular characterization of these compounds provides insights into sources and formation pathways of organic aerosols.The method of chemical derivatization followed by gas chromatography-flame ionization detection (GC-FID), gas chromatography/quadruple mass spectrometry (GC/QMS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) was used to identify hydroxy- and keto-diacids in remote marine aerosols. Atmospheric samples were collected at Chichijima Island in the western North Pacific and the diacids and related compounds were extracted with organic-free ultrapure water. A two-step derivatization technique was employed, using 14% BF3 /n-butanol for the butylation of carboxyl groups and acidic ketones followed by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) for the trimethylsilylation of hydroxyl groups.Several new peaks were detected in the gas chromatogram after trimethylsilylation of the dibutyl ester fraction. Based on mass spectral interpretation with authentic standards, we successfully identified and quantified a homologous series of hydroxydiacids, including tartaric and oxaloacetic acids. In addition, transformation of oxaloacetic acid into its enol form was elucidated.Utilizing GC-FID, GC/QMS and GC/TOFMS, hydroxy- and keto-diacids were identified in the remote marine aerosols. A complete structural characterization was achieved with extensive mass spectral analysis. Molecular distributions of hydroxydiacids generally showed the predominance of malic acid followed by tartronic acid. We consider that these hydroxydiacids are important intermediates in the atmospheric oxidation of organic aerosols to result in smaller diacids. Copyright © 2016 John WileySons, Ltd.
- Published
- 2015
43. 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
- Author
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Mingjie Xie, S. Hu, Sinan Gao, Gehui Wang, Kimitaka Kawamura, and Eri Tachibana
- Subjects
Total organic carbon ,Atmospheric Science ,δ13C ,chemistry.chemical_element ,lcsh:QC1-999 ,Isotopes of nitrogen ,Aerosol ,lcsh:Chemistry ,chemistry.chemical_compound ,lcsh:QD1-999 ,Total inorganic carbon ,chemistry ,Isotopes of carbon ,Environmental chemistry ,Sulfate ,Carbon ,lcsh:Physics - 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.
- Published
- 2010
44. Fluorescent water-soluble organic aerosols in the High Arctic atmosphere
- Author
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Leonard A. Barrie, Yele Sun, Lujie Ren, Kimitaka Kawamura, Zifa Wang, Mingyue Qin, Youhei Yamashita, Jing Chen, Pingqing Fu, Eri Tachibana, and Aijun Ding
- Subjects
Pollution ,Total organic carbon ,Multidisciplinary ,media_common.quotation_subject ,chemistry.chemical_element ,Particulates ,complex mixtures ,Article ,Atmosphere ,Arctic ,chemistry ,Isotopes of carbon ,Environmental chemistry ,Sunrise ,Environmental science ,Carbon ,media_common - Abstract
Organic aerosols are ubiquitous in the earth’s atmosphere. They have been extensively studied in urban, rural and marine environments. However, little is known about the fluorescence properties of water-soluble organic carbon (WSOC) or their transport to and distribution in the polar regions. Here, we present evidence that fluorescent WSOC is a substantial component of High Arctic aerosols. The ratios of fluorescence intensity of protein-like peak to humic-like peak generally increased from dark winter to early summer, indicating an enhanced contribution of protein-like organics from the ocean to Arctic aerosols after the polar sunrise. Such a seasonal pattern is in agreement with an increase of stable carbon isotope ratios of total carbon (δ13CTC) from −26.8‰ to −22.5‰. Our results suggest that Arctic aerosols are derived from a combination of the long-range transport of terrestrial organics and local sea-to-air emission of marine organics, with an estimated contribution from the latter of 8.7–77% (mean 45%).
- Published
- 2015
45. Identification of secondary fatty alcohols in atmospheric aerosols in temperate forests.
- Author
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Yuzo Miyazaki, Divyavani Gowda, Eri Tachibana, Yoshiyuki Takahashi, and Tsutom Hiura
- Subjects
FATTY alcohols ,ATMOSPHERIC aerosols ,TEMPERATE forests ,CHEMICAL reactions ,ICE nuclei ,POLLEN ,DECIDUOUS forests - Abstract
Fatty alcohols (FAs) are major components of surface lipids (waxes) and can act as surface-active organic aerosols in the atmosphere, influencing chemical reactions, particle lifetimes, and the formation of cloud droplets and ice nuclei. However, studies on the composition and source of the FAs in atmospheric aerosols are very limited. In this study, we identified five secondary FAs (SFAs) with C
27 and C29 from aerosol samples collected throughout one year at two different deciduous forest sites in Japan. Fatty diols, such as n-heptacosan-5,10-diol, were identified in atmospheric aerosols for the first time. Among the identified SFAs, n-nonacosan-10-ol was the most abundant compound, followed by n-nonacosan-5-10-diol at both of the forest sites. Concentrations of the SFAs exhibited distinct seasonal variation, with pronounced peaks during the growing season at each forest site. The SFAs showed significant correlation with sucrose, which is used as a molecular tracer of pollen. A significant fraction of the SFAs was attributed to the submicrometer particles in the growing season. The results indicate that they originated mostly from plant wax and could be used as useful tracers for primary biological aerosol particles. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
46. Long-term (2001-2013) observations of water-soluble dicarboxylic acids and related compounds over the western North Pacific: trends, seasonality and source apportionment
- Author
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Kimitaka Kawamura, Suresh K. R. Boreddy, and Eri Tachibana
- Subjects
Pollutant ,Multidisciplinary ,Azelaic acid ,Molecular composition ,010504 meteorology & atmospheric sciences ,Science ,Oxalic acid ,010501 environmental sciences ,Seasonality ,Particulates ,medicine.disease ,01 natural sciences ,Article ,chemistry.chemical_compound ,Water soluble ,chemistry ,Environmental chemistry ,medicine ,Glyoxal ,Medicine ,0105 earth and related environmental sciences ,medicine.drug - Abstract
To better understand the impact of East Asian pollutants on the molecular composition of marine organic aerosols, we conducted long-term (2001–2013) observations of water-soluble dicarboxylic acids and related compounds in total suspended particulate samples collected at Chichijima Island in the western North Pacific (WNP). Seasonal variations of all the diacids and related compounds showed maxima in winter and spring and minima in summer, except for azelaic acid (C9), which maximized in summer to autumn. The overall annual concentrations of the total diacids, ω-oxoacids and α-dicarbonyls showed an increase during 2001–2013. We found a significant (p 0.05) acids, and methylglyoxal (MeGly). In contrast, phthalic acid (p < 0.05) and glyoxal (Gly) showed a decrease in their trends. We also found a significant decrease in the trend of the Gly/MeGly mass ratios. These results demonstrate that the enhanced concentrations of diacids over the WNP are majorly attributed to the aqueous-phase photooxidation of biogenic volatile organic compounds from East Asia followed by long-range atmospheric transport. Further, positive matrix factorization analysis showed a biogenic photochemical contribution (42%) was the dominant source of oxalic acid in the WNP.
- Published
- 2017
47. Stable carbon isotopic compositions of low-molecularweight dicarboxylic acids, glyoxylic acid and glyoxal in tropical aerosols: implications for photochemical processes of organic aerosols
- Author
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Kimitaka Kawamura, Stelyus L. Mkoma, and Eri Tachibana
- Subjects
Atmospheric Science ,Azelaic acid ,Atmospheric chemistry ,glyoxal ,Inorganic chemistry ,Oxalic acid ,stable carbon isotope ratios ,chemistry.chemical_element ,lcsh:QC851-999 ,complex mixtures ,Tanzania ,oxalic acid ,PM2.5 and PM10 ,Stable carbon isotope ratios ,Oxalic acid, Diacids, Glyoxylic acid, Glyoxal, Organic aerosols, Tanzania, East Africa ,chemistry.chemical_compound ,glyoxylic acid ,medicine ,Glyoxylic acid ,Total organic carbon ,organic aerosols ,East Africa ,Decomposition ,chemistry ,Isotopes of carbon ,Environmental chemistry ,Glyoxal ,lcsh:Meteorology. Climatology ,diacids ,Carbon ,medicine.drug - Abstract
Tropical aerosols of PM 2.5 and PM 10 were collected at a rural site in Morogoro, Tanzania (East Africa), and analysed for stable carbon isotopic composition (δ 13 C) of dicarboxylic acids (C 2 –C 9 ), glyoxylic acid (ωC 2 ) and glyoxal (Gly) using gas chromatography/isotope ratio mass spectrometer. PM 2.5 samples showed that δ 13 C of oxalic (C 2 ) acid are largest (mean, −18.3±1.7‰) followed by malonic (C 3 , −19.6±1.0‰) and succinic (C 4 , −21.8±2.2‰) acids, whereas those in PM 10 are a little smaller: −19.9±3.1‰ (C 2 ), −20.2±2.7‰ (C 3 ) and −23.3±3.2‰ (C 4 ). The δ 13 C of C 2 –C 4 diacids showed a decreasing trend with an increase in carbon numbers. The higher δ 13 C values of oxalic acid can be explained by isotopic enrichment of 13 C in the remaining C 2 due to the atmospheric decomposition of oxalic acid or its precursors. δ 13 C of ωC 2 and Gly that are precursors of oxalic acid also showed larger values (mean, −22.5‰ and −20.2‰, respectively) in PM 2.5 than those (−26.7‰ and −23.7‰) in PM 10 . The δ 13 C values of ωC 2 and Gly are smaller than those of C 2 in both PM 2.5 and PM 10 . On the other hand, azelaic acid (C 9 ; mean, −28.5‰) is more depleted in 13 C, which is consistent with the previous knowledge; that is, C 9 is produced by the oxidation of unsaturated fatty acids emitted from terrestrial higher plants. A significant enrichment of 13 C in oxalic acid together with its negative correlations with relative abundance of C 2 in total diacids and ratios of water-soluble organic carbon and organic carbon further support that a photochemical degradation of oxalic acid occurs during long-range transport from source regions. Keywords: PM 2.5 and PM 10 , stable carbon isotope ratios, oxalic acid, diacids, glyoxylic acid, glyoxal, organic aerosols, Tanzania, East Africa (Published: 1 October 2014) Citation: Tellus B 2014, 66 , 23702, http://dx.doi.org/10.3402/tellusb.v66.23702
- Published
- 2014
48. Organic and inorganic markers and stable C-, N-isotopic compositions of tropical coastal aerosols from megacity Mumbai: sources of organic aerosols and atmospheric processing
- Author
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Kimitaka Kawamura, G. S. Umarji, Prabhat K. Gupta, R. S. Patil, Eri Tachibana, and Shankar G. Aggarwal
- Subjects
Atmospheric Science ,Nitrogen ,chemistry.chemical_element ,Inorganic ions ,Southeast-Asia ,complex mixtures ,Atmosphere ,lcsh:Chemistry ,chemistry.chemical_compound ,Dicarboxylic-Acids ,Mass-Spectrometry ,East-Asia ,Total organic carbon ,Northern Japan Implication ,δ13C ,Levoglucosan ,Indian-Ocean Experiment ,δ15N ,lcsh:QC1-999 ,Carbon ,Aerosol ,Ketocarboxylic Acids ,chemistry ,lcsh:QD1-999 ,Environmental chemistry ,Environmental science ,Alpha-Dicarbonyls ,lcsh:Physics - Abstract
To better understand the sources of PM10 samples in Mumbai, India, aerosol chemical composition, i.e., total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied together with specific markers such as methanesulfonate (MSA), oxalic acid (C2), azelaic acid (C9), and levoglucosan. The results revealed that biofuel/biomass burning and fossil fuel combustion are the major sources of the Mumbai aerosols. Nitrogen-isotopic (δ15N) composition of aerosol total nitrogen, which ranged from 18.1 to 25.4‰, also suggests that biofuel/biomass burning is a predominate source in both the summer and winter seasons. Aerosol mass concentrations of major species increased 3–4 times in winter compared to summer, indicating enhanced emission from these sources in the winter season. Photochemical production tracers, C2 diacid and nssSO42−, do not show diurnal changes. Concentrations of C2 diacid and WSOC show a strong correlation (r2 = 0.95). In addition, WSOC to OC (or TC) ratios remain almost constant for daytime (0.37 ± 0.06 (0.28 ± 0.04)) and nighttime (0.38 ± 0.07 (0.28 ± 0.06)), suggesting that mixing of fresh secondary organic aerosols is not significant and the Mumbai aerosols are photochemically well processed. Concentrations of MSA and C9 diacid present a positive correlation (r2 = 0.75), indicating a marine influence on Mumbai aerosols in addition to local/regional influence. Backward air mass trajectory analyses further suggested that the Mumbai aerosols are largely influenced by long-range continental and regional transport. Stable C-isotopic ratios (δ13C) of TC ranged from −27.0 to −25.4‰, with slightly lower average (−26.5 ± 0.3‰) in summer than in winter (−25.9 ± 0.3‰). Positive correlation between WSOC/TC ratios and δ13C values suggested that the relative increment in 13C of wintertime TC may be caused by prolonged photochemical processing of organic aerosols in this season. This study suggests that in winter, the tropical aerosols are more aged due to longer residence time in the atmosphere than in summer aerosols. However, these conclusions are based on the analysis of a limited number of samples (n=25) and more information on this topic may be needed from other similar coastal sites in future.
- Published
- 2012
49. Dicarboxylic acids, ketocarboxylic acids,α-dicarbonyls, fatty acids, and benzoic acid in urban aerosols collected during the 2006 Campaign of Air Quality Research in Beijing (CAREBeijing-2006)
- Author
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Yan Cheng, Kimitaka Kawamura, Kin Fai Ho, Eri Tachibana, Steven Sai Hang Ho, Tong Zhu, and Shuncheng Lee
- Subjects
Pollution ,Atmospheric Science ,Meteorology ,media_common.quotation_subject ,Oxalic acid ,Soil Science ,Aquatic Science ,Oceanography ,chemistry.chemical_compound ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Air quality index ,Earth-Surface Processes ,Water Science and Technology ,Benzoic acid ,media_common ,chemistry.chemical_classification ,Pollutant ,Ecology ,Paleontology ,Forestry ,Phthalic acid ,Geophysics ,Dicarboxylic acid ,chemistry ,Space and Planetary Science ,Succinic acid ,Environmental chemistry - Abstract
Ground-based studies of PM2.5 were conducted for determination of 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid, during the Campaign of Air Quality Research in Beijing 2006 (CAREBeijing-2006; 21 August to 4 September 2006) at urban (Peking University, PKU) and suburban (Yufa) sites of Beijing. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C2) was the most abundant species, followed by phthalic acid (Ph) and succinic acid (C4) at both sites. The sum of three dicarboxylic acids accounted for 71% and 74% of total quantified water-soluble organics (327-1552 and 329-1124 ng m^[-3]) in PKU and Yufa, respectively. Positive correlation was found between total quantified water-soluble species and water-soluble organic compounds (WSOC). On a carbon basis, total quantified dicarboxylic acids and ketocarboxylic acids and dicarbonyls account for up to 14.2% and 30.4% of the WSOC in PKU and Yufa, respectively, suggesting that they are the major WSOC fractions in Beijing. The distributions of fatty acids are characterized by a strong even carbon number predominance with maximum at hexadecanoic acid (C16:0). The ratio of octadecanoic acid (C18:0) to hexadecanoic acid (C16:0) (0.39-0.85, with an average of 0.36) suggests that in addition to vehicular emissions, an input from cooking emissions is important, as is biogenic emission. Benzoic acid that has been proposed as a primary pollutant from vehicular exhaust and a secondary product from photochemical reactions was found to be abundant: 72.2 ± 58.1 ng m^[-3] in PKU and 78.0 ± 47.3 ng m^[-3] in Yufa. According to the 72 hour back trajectory analysis, when the air mass passed over the southern or southeastern part of Beijing (24-25 August and 1-2 September), the highest concentrations of organic compounds were observed. On the contrary, when the clean air masses came straight from the north during 3-4 September, the lowest levels of organic compounds were recorded. This study demonstrates that pollution episodes in Beijing were strongly controlled by wind direction; that is, air quality in Beijing is good when air masses originate from the north and northwest, whereas it deteriorates when the air mass originates from the south and southeast.
- Published
- 2010
50. Elevated nitrogen isotope ratios of tropical Indian aerosols from Chennai: Implication for the origins of aerosol nitrogen in South and Southeast Asia
- Author
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T. Swaminathan, Chandra Mouli Pavuluri, Kimitaka Kawamura, and Eri Tachibana
- Subjects
biomass burning ,summer ,Atmospheric Science ,aerosol ,Air pollution ,Cow-dung samples ,South Asia ,medicine.disease_cause ,ammonia ,chemistry.chemical_compound ,Isotopes ,Nitrogen isotope ratio ,General Environmental Science ,Isotope analysis ,seasonal variation ,concentration (composition) ,Atmospheric aerosols ,Nitrogen ,Southeast Asia ,Isotopes of nitrogen ,point source ,levoglucosan ,nitrogen isotope ,priority journal ,Environmental chemistry ,ammonium sulfate ,biofuel ,inorganic chemicals ,night ,Asia ,Meteorology ,chemistry.chemical_element ,India ,complex mixtures ,Atmospheric thermodynamics ,tropics ,Ammonia ,nitrate ,Nitrogen isotope ratios ,gas ,tropical environment ,medicine ,Animalia ,controlled study ,Tropical Indian aerosols ,particulate matter ,biomass ,Tropics ,δ15N ,winter ,Aerosol ,chemistry ,feces ,manure ,isotopic ratio ,Environmental science ,Source of aerosol nitrogen ,laboratory - Abstract
To better understand the origins of aerosol nitrogen, we measured concentrations of total nitrogen (TN) and its isotope ratios (?15N) in tropical Indian aerosols (PM10) collected from Chennai (13.04�N; 80.17�E) on day- and night-time basis in winter and summer 2007. We found high ?15N values (+15.7 to +31.2�) of aerosol N (0.3-3.8 ?g m-3), in which NH4 + is the major species (78%) with lesser contribution from NO3 - (6%). Based on the comparison of ?15N in Chennai aerosols with those reported for atmospheric aerosols from mid-latitudes and for the particles emitted from point sources (including a laboratory study), as well as the ?15N ratios of cow-dung samples (this study), we found that the atmospheric aerosol N in Chennai has two major sources; animal excreta and bio-fuel/biomass burning from South and Southeast Asia. We demonstrate that a gas-to-particle conversion of NH3 to NH4HSO4 and (NH4)2SO4 and the subsequent exchange reaction between NH3 and NH4 + are responsible for the isotopic enrichment of 15N in aerosol nitrogen. � 2010 Elsevier Ltd.
- Published
- 2010
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