Published Papers - SHIMADA Kojiro

Size-segregated sulfate on top of Mt. Fuji transported from Sakurajima volcano eruption

Kojiro Shimada, Kei Suzuki, Shungo Kato, Shuuichi Itahashi, Shiro Hatakeyama

■■■     2024.05

Type of publication: Research paper (other science council materials etc.)

　View Summary

Size-segregated aerosol samples were collected on Mt. Fuji with a cascade impactor during daytime and nighttime. We analyzed for their ionic and element compositions. Samples were collected from 29 July to 2 August (first period) and from 19 to 21 August 2013 (second period). Based on combined chemical components and CMAQ, in the first period, the air masses had been transported from East Asia. In the second period, the Sakurajima volcano eruption had been transported. NH4+, SO42–and elements were the major ions in 2.5 < Dp ≤ 10 during the second period. The slope of a linear regression of non-sea-salt (nss)-SO42– versus NH4+ was nearly unity, particularly during the first period. However, nss-SO42– in coarse aerosol was shifted in great excess in the second period. We have observed a rare phenomenon in which sulfate shifts to 2.5 < Dp ≤ 10. Although the formation process of (NH4)2SO4 in coarse particle is hypothesized two mechanisms, we hypothesize the third mechanism in this study. Currently, radiative forcing is being discussed for the detection of volcanic aerosols using satellites with particle sizes of 1.2 µm. If this can be clarified, it will improve the reproducibility of sulfate radiative forcing.

• Access this article

  DOI

Possibility of condensation of nitric acid for cloud condensation nucleus in the summer at Mt. Fuji

Kojiro Shimada, Yoshun Geka, Shungo Kato, Chak K. Chan, Yong Pyo Kim, Chang-Feng Ou-Yang, Neng-Huei Lina, Shiro Hatakeyama

Atmospheric Pollution Research     2023.09 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Possibility of condensation of nitric acid for cloud condensation nucleus in the summer at Mt. Fuji

Kojiro Shimada, Yoshun Geka, Shungo Kato, Chak K. Chan, Yong Pyo Kim, Chang-Feng Ou-Yang, Neng-Huei Lina, Shiro Hatakeyama

■■■     2023.09 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Evaluation of oxidative ability after photoirradiation using urban aerosols

Yurie Gotoh, Kojiro Shimada, Shuhei Murakami, Takumi Yamawaki, Ayaka Mitsukawa, Hiroshi Okochi

    2023.07 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Evaluation of oxidative ability after photoirradiation using urban aerosols

Yurie Gotoh, Kojiro Shimada, Shuhei Murakami, Takumi Yamawaki, Ayaka Mitsukawa, Hiroshi Okochi

    2023.07 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Offline analysis of the chemical composition and hygroscopicity of sub-micrometer aerosol at an Asian outflow receptor site and comparison with online measurements

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;Michihiro Mochida

Atmospheric Chemistry and Physics     2022.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Offline analysis of the chemical composition and hygroscopicity of sub-micrometer aerosol at an Asian outflow receptor site and comparison with online measurements

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, Michihiro Mochida

Atmospheric Chemistry and Physics ( Copernicus GmbH )  22 ( 8 ) 5515 - 5533   2022.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

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.

• Access this article

  DOI Repository

Effects of changes in polycyclic aromatic hydrocarbons (PAHs) emissions and degradation on their concentrations in Tokyo from 2007 and 2016

Kojiro Shimada, Masayuki Nohchi, Koji Maeshima, Tomonori Uchino, Yusuke Kobayashi, Kazuki Ono, Hiroko Ogata, Naoya Katsumi, Koji Inazu, Hiroshi Okochi

Scientific Reports ( Springer Nature )  12 ( 4249 ) 1 - 9   2022.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Effects of changes in polycyclic aromatic hydrocarbons (PAHs) emissions and degradation on their concentrations in Tokyo from 2007 and 2016.

Shimada K, Nohchi M, Maeshima K, Uchino T, Kobayashi Y, Ono K, Ogata H, Katsumi N, Inazu K, Okochi H

Scientific reports ( Springer Science and Business Media LLC )  12 ( 1 ) 4249   2022.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

Abstract The concentrations of polycyclic aromatic hydrocarbons (PAHs) in aerosol were measured in Shinjuku, which is central Tokyo, Japan, for 10 years from 2007 to 2016. The effects of changes in emission sources and their degradation by reaction with ozone were assessed in this study. There was no significant increasing or decreasing trend of the PAH concentrations during 10 years (P > 0.05). The average selected seven the PAH concentrations (0.88 ng m⁻³) during 10 years was lower than those in New York and Paris. However, the trend of ozone concentrations is increasing in central Tokyo. This inconsistency raises a question. Did the fact that the ozone concentration was higher than the PAH concentrations promote PAH degradation? To apportion the PAH sources, we used PAH concentration profiles and positive matrix factorization analysis. The contribution of vehicle emissions to the PAHs ranged from 40 to 80%. Ozone concentrations increased by 3.70%/year during 10 years. The theoretical degradation rates of PAHs by ozone, which were calculated using a pseudo-first-order rate equation, suggested that the lifetimes of benzo[a]pyrene (BaP) decreased by 1 min from 2007 to 2016. We investigated the aging of BaP using the profile of the isomer ratios. We found that the aging of BaP at the urban and roadside sites were nearly identical indicating aging regardless of the season. Although the decomposition of BaP is promoted by the photochemical oxidation reaction, this result suggests that a certain threshold value exists as the degree of the decomposition. This degradation of PAH can improve chemical loss processes in air quality model.

• Access this article

  DOI Repository
• Search related information
  PubMed

Disentangling the contribution of the transboundary out-flow from the Asian continent to Tokyo, Japan

Kojiro Shimada, Manatsu Mizukoshi, Chak K.Chan, Yong PyoKim, Neng-Huei Lin, Kazuhide Matsuda, Syuichi Itahashi, Yoshihiro Nakashima, ShungoKato, ShiroHatakeyama

Environmental Pollution ( Elsevier )  281 ( 1 )   2021.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Disentangling the contribution of the transboundary out-flow from the Asian continent to Tokyo, Japan.

Shimada K, Mizukoshi M, Chan CK, Kim YP, Lin NH, Matsuda K, Itahashi S, Nakashima Y, Kato S, Hatakeyama S

Environmental pollution (Barking, Essex : 1987) ( Elsevier )  286 ( 1 ) 117280   2021.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

We assessed the contribution of transboundary air pollutants (TAPs) transported from China to Tokyo using the Pb(0.5<Dp < 1)/Cu(2.5<Dp < 10) index. We conducted intensive observations over four seasons during 2014–2015 and analyzed ionic components and thirteen elements in size-segregated aerosols collected at the top of a 30-m-high tower in a hilly forested area of the Field Museum Tamakyuryo (FM Tama), in a western suburb of Tokyo. In order to evaluate if the Pb(0.5<Dp < 1)/Cu(2.5<Dp < 10) ratio can be applied in Tokyo as the megacity, the annual average concentration of Pb at Cape Hedo, Kumamoto city, on the west side of Japan, was higher than that of Pb at Tokyo, on the east side; this result indicates that TAPs affect western Japan more than eastern Japan. We inferred the main source of Cu to be braking abrasion from cars at local scale on the basis of its enrichment factor and size distribution. From the Pb(0.5<Dp < 1)/Cu(2.5<Dp < 10) ratio and sulfate concentration, we inferred that the highest contribution of TAPs to the total mass concentration in Tokyo occurred in spring, when TAPs accounted for 55%, 72%, and 53% of the total mass concentration in the 0.1 < Dp < 0.5, 0.5 < Dp < 1, and 1 < Dp < 2.5 fractions, respectively. These results can contribute to assessment of TAPs in Tokyo.

• Access this article

  DOI
• Search related information
  PubMed

Long-term Measurements of Carbonaceous Aerosol at Cape Hedo, Okinawa, Japan: Effects of Changes in Emissions in East Asia

Shimada Kojiro, Takami Akinori, Ishida Takatsugu, Taniguchi Yuta, Hasegawa Shuichi, Chan Chak K., Kim Yong Pyo, Lin Neng-Hue, Hatakeyama Shiro

AEROSOL AND AIR QUALITY RESEARCH   21 ( 9 )   2021.09 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

東アジアの越境大気汚染問題:国際共同観測ネットワークによる東アジアの 越境大気汚染の解明

Kojiro Shimada

Chemistry & chemical industry   74 ( 3 ) 212 - 213   2021.03 [ Peer Review Accepted ]

Type of publication: Research paper (bulletin of university, research institution)

Degradation of PAHs during long range transport based on simultaneous measurements at Tuoji Island, China, and at Fukue Island and Cape Hedo, Japan.

Shimada K, Nohchi M, Yang X, Sugiyama T, Miura K, Takami A, Sato K, Chen X, Kato S, Kajii Y, Meng F, Hatakeyama S

Environmental pollution (Barking, Essex : 1987)   260   113906   2020.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI
• Search related information
  PubMed

Estimation of background PM2.5 concentrations for an air-polluted environment

Wang, S. H., Hung, R. Y., Lin, N. H., Gómez-Losada, Á., Pires, J. C. M., Shimada, K., Hatakeyama, S., & Takami, A.

Atmospheric Research ( Elsevier )  231   2020 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Controlling Factors of Volatile Organic Compounds in Cloud Water at the Summit of Mt. Fuji in the Free Troposphere during the Summer

Yamawaki Takumi, Miura Kazuhiko, Toda Kei, Wada Ryuichi, Takeuchi Masaki, Kobayashi Hiroshi, Dokiya Yukiko, Hatakeyama Shiro, Okochi Hiroshi, Yamamoto Shuji, Yamanokoshi Eri, Shimada Kojiro, Ogata Hiroko, Katsumi Naoya, Minami Yukiya, Kato Shungo

Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi ( Japan Society for Atmospheric Environment )  55 ( 5 ) 191 - 203   2020 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

<p>At the summit of Mt. Fuji in July and August from 2012 to 2018, 27 kinds of anthropogenic volatile organic compounds (AVOCs) and 6 types of biogenic volatile organic compounds (BVOCs) in the air and in cloud water were determined. AVOCs occupied about 90% of the VOCs in the cloud water (volume-weighted mean VOCs concentration: 2.07 nM, <i>n</i>=159) and the main component was toluene, reflecting its high concentration in the ambient air. The concentration of the AVOCs in the cloud water was high when the airmass was transported from the southern continent and was about 1.5 times higher than that when it came from the ocean. The concentration of toluene in the cloud water decreased exponentially with the increase in the total ion concentration. The concentrations of some VOCs such as chloroform, <i>o</i>-xylene, and limonen in the cloud water were several times higher than their Henry's law predicted values. Among the chlorinated hydrocarbons, highly hydrophobic chloroform was more concentrated than dichloromethane in the cloud water. Atmospheric surfactants such as HULIS (Humic-like Substances) could affect the enrichment of the VOCs in the cloud water even in the free troposphere.</p>

• Access this article

  DOI Repository

Estimation of background PM2.5 concentrations for an air-polluted environment

Wang, S. H, Hung, R. Y, Lin, N. H, Gómez-Losada, Á, Pires, J. C. M, Shimada, K, Hatakeyama, S, Takami, A

Atmospheric Research ( Elsevier )  231   104636 - 104636   2020 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Seasonal and annual changes in PAH concentrations in a remote site in the Pacific Ocean.

Miura K, Shimada K, Sugiyama T, Sato K, Takami A, Chan CK, Kim IS, Kim YP, Lin NH, Hatakeyama S

Scientific reports   9 ( 1 ) 12591   2019.08 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository
• Search related information
  PubMed

Seasonal and annual changes in PAH concentrations in a remote site in the Pacific Ocean

Miura, K; Shimada, K; Sugiyama, T; Sato, K; Takami, A; Chan, CK; Kim, IS; Kim, YP; Lin, NH; Hatakeyama, S

SCIENTIFIC REPORTS ( Scientific Reports )  9 ( 1 ) 12591   2019.08 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository
• Search related information
  PubMed

Sources of high sulfate aerosol concentration observed at cape hedo in spring 2012

Itahashi S.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  19 ( 3 ) 587 - 600   2019.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Comprehensive measurements of atmospheric OH reactivity and trace species within a suburban forest near Tokyo during AQUAS-TAMA campaign

Ramasamy S.

Atmospheric Environment ( Atmospheric Environment )  184   166 - 176   2018.07 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Concentrations of metallic elements in long-range-transported aerosols measured simultaneously at three coastal sites in China and Japan

Shimada K.

Journal of Atmospheric Chemistry ( Journal of Atmospheric Chemistry )  75 ( 2 ) 123 - 139   2018.06 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Model estimation of sulfate aerosol sources collected at Cape Hedo during an intensive campaign in october–november, 2015

Itahashi S.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  17 ( 12 ) 3079 - 3090   2017.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Measurement of ambient PAHs in Kumamoto: Differentiating local and transboundary air pollution

Taichi Sugiyama, Kojiro Shimada, Kaori Miura, Neng-Huei Lin, Yong Pyo Kim, Chak K. Chan, Akinori Takami, Shiro Hatakeyama

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  17 ( 12 ) 3106 - 3118   2017.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Contributions of long-range transported and locally emitted nitrate in size-segregated aerosols in Japan at Kyushu and Okinawa

Tatsuta S.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  17 ( 12 ) 3119 - 3127   2017.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Comparison of aerosol hygroscopcity, volatility, and chemical composition between a suburban site in the Pearl River Delta region and a marine site in Okinawa

Cai M.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  17 ( 12 ) 3194 - 3208   2017.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Characteristics of summertime volatile organic compounds in the lower free troposphere: Background measurements at Mt. Fuji

Ou-Yang C.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  17 ( 12 ) 3037 - 3051   2017.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Transboundary and local air pollutants in Western Japan distinguished on the basis of ratios of metallic elements in size-segregated aerosols

Taniguchi, Y., Shimada, K., Takami, A., Lin, N. H., Chan, C. K., Kim, Y. P., & Hatakeyama, S.

Aerosol and Air Quality Research   17 ( 12 ) 3141 - 3150   2017 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Chemical characterization of wintertime aerosols over Islands and mountains in East Asia: Impacts of the continental Asian outflow.

Pani, S. K., Lee, C. T., Chou, C. C. K., Shimada, K., Hatakeyama, S., Takami, A., Wang, S. H., & Lin, N. H.

Aerosol and Air Quality Research   17 ( 12 ) 3006 - 3036   2017 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

Emission of biogenic volatile organic compounds from trees along streets and in urban parks in Tokyo, Japan

Matsunaga S.

Asian Journal of Atmospheric Environment ( Asian Journal of Atmospheric Environment )  11 ( 1 ) 29 - 32   2017 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Characteristics of carbonaceous aerosols in large-scale Asian wintertime outflows at Cape Hedo, Okinawa, Japan

Shimada K.

Journal of Aerosol Science ( Journal of Aerosol Science )  100   97 - 107   2016.10 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI

国際共同観測ネットワークによる東アジアの越境大気汚染の解明

Kojiro Shimada

  ( 33 ) 6 - 7   2015.08 [ Peer Review Accepted ]

Type of publication: Research paper (other science council materials etc.)

<b>Size-Segregated Chemical Analyses of Particles Transported from East Asia and Their Transformation Mechanisms during the Transport </b>

YUMOTO Yayoi, SHIMADA Kojiro, ARAKI Yushi, YOSHINO Ayako, TAKAMI Akinori, HATAKEYAMA Shiro

Earozoru Kenkyu ( Japan Association of Aerosol Science and Technology )  30 ( 2 ) 115 - 125   2015.06 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

In order to investigate the processes of chemical transformations of aerosol transported from East Asia to Japan the concentrations of ionic species in size-segregated aerosols were measured in Cape Hedo, Okinawa, Japan. By use of a cascade impactor (Nano sampler) we collected aerosols at 5 stages. Throughout the observation periods, species originated from anthropogenic sources such as NH₄⁺ and nss-SO₄^2- were dominant in fine mode particles (0.1–0.5 μm, 0.5–1 μm), whereas species originated from natural sources such as Na⁺ and <br/>Cl^- were dominant in coarse mode particles (2.5–10μm, >10μm). The (Cl^-+NO₃^-)/Na⁺ ratio in coarse mode, 1.14 in equivalent basis, was very close to Cl^-/Na⁺ of sea water (1.17), which indicated that NH₄NO₃ was decomposed to gaseous NH₃ and HNO₃ during the long-range transport, and HNO₃ deposited on sea-salt particles. The concentrations of NH₄⁺, nss-SO₄^2- and nss-K⁺ in fine mode were higher during high pressure episodes; it suggests that the fine particles emitted from anthropogenic sources (<i>e.g.</i> biomass burning) were transported with a migratory anticyclone. Increase of nss-Ca²⁺ and nss-SO₄^2- in coarse mode during Asian dust episode implied that surface reactions with gaseous species on CaCO₃ particles occurred during the transport.

• Access this article

  DOI

Mode and place of origin of carbonaceous aerosols transported from east Asia to cape Hedo, Okinawa, Japan

Shimada K.

Aerosol and Air Quality Research ( Aerosol and Air Quality Research )  15 ( 3 ) 799 - 813   2015 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Ozone and Formaldehyde Formation by UV Irradiation to Biogenic VOC Added Urban Air in Tokyo

Matsunaga Sou N., Ishikura Atsushi, Shimada Kojiro, Hoshi Junya, Saito Shinji, Ueno Hiroyuki

Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi ( Japan Society for Atmospheric Environment )  50 ( 5 ) 233 - 238   2015 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

The high ozone concentration in urban atmospheres including Tokyo is still one of the important environmental issues. One of the possible causes is ozone formation by unconsidered VOC. In this study, we performed chamber experiments to understand the importance of biogenic VOCs emitted from urban green flora. Isoprene and α-pinene were added to ambient air and irradiated by UV. The ozone and formaldehyde concentrations were measured to compare the ozone formation potential with the control. The ozone formation potential of isoprene was also compared to that of toluene. Considering the typical emission rates of isoprene and α-pinene, 10 and 0.7 ppbv of these VOCs were separately added to the ambient air in the chamber. Both isoprene and α-pinene showed approximately 30% higher ozone concentrations compared to the control after 6 h of UV irradiation. On the other hand, isoprene showed a 33% higher ozone concentration than toluene for a 10 ppbv addition to the ambient air after 6 h of reaction. This means that the ozone formation by biogenic VOC is important as well as that of anthropogenic VOCs, such as toluene, which is a typical anthropogenic VOC. The possibility that biogenic VOCs emitted from green areas and street trees are important for ozone formation has been suggested by this study.

• Access this article

  DOI Repository

<b>Size-Segregated Chemical Analyses of Particles Transported from East Asia and Their Transformation Mechanisms during the Transport </b>

YUMOTO Yayoi, SHIMADA Kojiro, ARAKI Yushi, YOSHINO Ayako, TAKAMI Akinori, HATAKEYAMA Shiro

Earozoru Kenkyu ( Japan Association of Aerosol Science and Technology )  30 ( 2 ) 115 - 125   2015 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

　View Summary

In order to investigate the processes of chemical transformations of aerosol transported from East Asia to Japan the concentrations of ionic species in size-segregated aerosols were measured in Cape Hedo, Okinawa, Japan. By use of a cascade impactor (Nano sampler) we collected aerosols at 5 stages. Throughout the observation periods, species originated from anthropogenic sources such as NH₄⁺ and nss-SO₄^2- were dominant in fine mode particles (0.1–0.5 μm, 0.5–1 μm), whereas species originated from natural sources such as Na⁺ and <br/>Cl^- were dominant in coarse mode particles (2.5–10μm, >10μm). The (Cl^-+NO₃^-)/Na⁺ ratio in coarse mode, 1.14 in equivalent basis, was very close to Cl^-/Na⁺ of sea water (1.17), which indicated that NH₄NO₃ was decomposed to gaseous NH₃ and HNO₃ during the long-range transport, and HNO₃ deposited on sea-salt particles. The concentrations of NH₄⁺, nss-SO₄^2- and nss-K⁺ in fine mode were higher during high pressure episodes; it suggests that the fine particles emitted from anthropogenic sources (<i>e.g.</i> biomass burning) were transported with a migratory anticyclone. Increase of nss-Ca²⁺ and nss-SO₄^2- in coarse mode during Asian dust episode implied that surface reactions with gaseous species on CaCO₃ particles occurred during the transport.

• Access this article

  DOI

Ozone and Formaldehyde Formation by UV Irradiation to Biogenic VOC Added Urban Air in Tokyo

Matsunaga Sou N, Ishikura Atsushi, Shimada Kojiro, Hoshi Junya, Saito Shinji, Ueno Hiroyuki

Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi ( Japan Society for Atmospheric Environment )  56th ( 5 ) 233 - 238   2015 [ Peer Review Accepted ]

Type of publication: Research paper (other science council materials etc.)

　View Summary

The high ozone concentration in urban atmospheres including Tokyo is still one of the important environmental issues. One of the possible causes is ozone formation by unconsidered VOC. In this study, we performed chamber experiments to understand the importance of biogenic VOCs emitted from urban green flora. Isoprene and α-pinene were added to ambient air and irradiated by UV. The ozone and formaldehyde concentrations were measured to compare the ozone formation potential with the control. The ozone formation potential of isoprene was also compared to that of toluene. Considering the typical emission rates of isoprene and α-pinene, 10 and 0.7 ppbv of these VOCs were separately added to the ambient air in the chamber. Both isoprene and α-pinene showed approximately 30% higher ozone concentrations compared to the control after 6 h of UV irradiation. On the other hand, isoprene showed a 33% higher ozone concentration than toluene for a 10 ppbv addition to the ambient air after 6 h of reaction. This means that the ozone formation by biogenic VOC is important as well as that of anthropogenic VOCs, such as toluene, which is a typical anthropogenic VOC. The possibility that biogenic VOCs emitted from green areas and street trees are important for ozone formation has been suggested by this study.

• Access this article

  DOI
• Search related information
  J-GLOBAL

Mode and Place of Origin of Carbonaceous Aerosols Transported From East Asia to Cape Hedo, Okinawa, Japan

Kojiro Shimada, Masamichi Shimada, Akinori Takami, Shuichi Hasegawa, Akihiro Fushimi, Takemitsu Arakaki, Watanabe Izumi, Shiro Hatakeyama

Aerosol and Air Quality Research ( Taiwan Association for Aerosol Research )  15 ( 3 ) 799 - 813   2015 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  DOI Repository

Aerial observation of trans-boundary air pollution form East Asia - Results of campaign in March, 2012

Shiro Hatakeyama , Kojiro Shimada , Miyako Koga , Miho Tanabe , Yasuhiro Sadanaga , Fujiwara Hiroshi , Hiroshi Bandow , Zhang Daizhou , Kotaro Murata , Kikuo Okuyama , Takashi Ogi , Toshiyuki Fujimoto , Akifumi Seto , Yusuke Kuromiya , Shusuke Nakajima , Shungo Kato , Yoshizumi Kajii , Atsushi Shimizu , Nobuo Sugimoto , Akinori Takami , Takemitsu Arakaki

JAPAN ASSOC AEROSOL SCI & TECHNOLOGY     265 - 266   2012.12 [ Peer Review Accepted ]

Type of publication: Research paper (international conference proceedings)

　View Summary

Aerial observation was made on March 10th, 11th, 13th, and 146, 2012 over the northern part of the East China Sea. The flight area was between Fukue Island, Japan and a point above the East China Sea about 220 km south of Jeju Island, Korea. Level flights were made at 500, 1000, 2000, 3000 m asl. Circulating flights at altitudes of 500, 1000, 2000, and 3000 m were also made above Fukue Island (on 116, 13th, and 14th) where ground-based observation site is in order to observe vertical distribution. Chemical analyses of aerosols were performed by use of filter sampling of aerosols with a hi-volume tape sampler and subsequent analyses with ICP-MS (7Li, 23Na, 24Mg, 27Al, 39 K, 43Ca, 51V, 55Mn, 57Fe, 59Co, 63Cu, 66Zn, 69Ga, 75As, 82Se, 85Rb, 88Sr, 107Ag, 111Cd, 115In, 121Sb, 133Cs, 205T1, 208Pb) for metallic elements. Gases and aerosol conc. were also measured.

Aerial observation of trans-boundary air pollution form East Asia - Results of campaign in March, 2012

Shiro Hatakeyama, Kojiro Shimada, Miyako Koga, Miho Tanabe, Yasuhiro Sadanaga, Fujiwara Hiroshi, Hiroshi Bandow, Zhang Daizhou, Kotaro Murata, Kikuo Okuyama, Takashi Ogi, Toshiyuki Fujimoto, Akifumi Seto, Yusuke Kuromiya, Shusuke Nakajima, Shungo Kato, Yoshizumi Kajii, Atsushi Shimizu, Nobuo Sugimoto, Akinori Takami, Takemitsu Arakaki

29TH SYMPOSIUM ON AEROSOL SCIENCE AND TECHNOLOGY, 2012 ( JAPAN ASSOC AEROSOL SCI & TECHNOLOGY )    265 - 266   2012 [ Peer Review Accepted ]

Type of publication: Research paper (international conference proceedings)

　View Summary

Aerial observation was made on March 10th, 11th, 13th, and 146, 2012 over the northern part of the East China Sea. The flight area was between Fukue Island, Japan and a point above the East China Sea about 220 km south of Jeju Island, Korea. Level flights were made at 500, 1000, 2000, 3000 m asl. Circulating flights at altitudes of 500, 1000, 2000, and 3000 m were also made above Fukue Island (on 116, 13th, and 14th) where ground-based observation site is in order to observe vertical distribution. Chemical analyses of aerosols were performed by use of filter sampling of aerosols with a hi-volume tape sampler and subsequent analyses with ICP-MS (7Li, 23Na, 24Mg, 27Al, 39 K, 43Ca, 51V, 55Mn, 57Fe, 59Co, 63Cu, 66Zn, 69Ga, 75As, 82Se, 85Rb, 88Sr, 107Ag, 111Cd, 115In, 121Sb, 133Cs, 205T1, 208Pb) for metallic elements. Gases and aerosol conc. were also measured.

Variation of carbonaceous aerosol in polluted air mass transported from East Asia and evaluation of their source origin

SHIMADA Kojiro, TAKAMI Akinori, KATO Shungo, KAJII Yoshizumi, HATAKEYAMA Shiro

Journal of Japan Society for Atmospheric Environment   46 ( 1 ) 1 - 9   2011.01 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

• Access this article

  Repository