Faculty Profiles - MOCHIDA, Michihiro

Papers - MOCHIDA, Michihiro

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In Situ Surface Tension Measurement of Deliquesced Aerosol Particles Reviewed

Masao Gen, Akihide Hibara, Phuong Nguyet Phung, Yuzo Miyazaki, Michihiro Mochida

The Journal of Physical Chemistry A Vol. 127 ( 29 ) page： 6100 - 6108 2023.7

Evaluation of a method to quantify the number concentrations of submicron water-insoluble aerosol particles based on filter sampling and complex forward-scattering amplitude measurements Reviewed

Sho Ohata, Nobuhiro Moteki, Hikaru Kawanago, Yutaka Tobo, Kouji Adachi, Michihiro Mochida

Aerosol Science and Technology Vol. 57 ( 10 ) page： 1013 - 1030 2023.6

Fluorescence of solvent-extractable organics in sub-micrometer forest aerosols in Hokkaido, Japan Reviewed

Sonia Afsana, Ruichen Zhou, Yuzo Miyazaki, Eri Tachibana, Dhananjay Kumar Deshmukh, Kimitaka Kawamura, Michihiro Mochida

Atmospheric Environment Vol. 303 page： 119710 2023.6

Relationships of the Hygroscopicity of HULIS With Their Degrees of Oxygenation and Sources in the Urban Atmosphere Reviewed International coauthorship

Ruichen Zhou, Yange Deng, Bhagawati Kunwar, Qingcai Chen, Jing Chen, Lujie Ren, Kimitaka Kawamura, Pingqing Fu, Michihiro Mochida

Journal of Geophysical Research: Atmospheres Vol. 127 ( 24 ) 2022.12

Water Solubility Distribution of Organic Matter Accounts for the Discrepancy in Hygroscopicity among Sub- and Supersaturated Humidity Regimes Reviewed International coauthorship

Wen-Chien Lee, Yange Deng, Ruichen Zhou, Masayuki Itoh, Michihiro Mochida, Mikinori Kuwata

Environmental Science & Technology Vol. 56 ( 24 ) page： 17924 - 17935 2022.12

Number‐Size Distribution and CCN Activity of Atmospheric Aerosols in the Western North Pacific During Spring Pre‐Bloom Period: Influences of Terrestrial and Marine Sources Reviewed

Kaori Kawana, Yuzo Miyazaki, Yuko Omori, Hiroshi Tanimoto, Sara Kagami, Koji Suzuki, Youhei Yamashita, Jun Nishioka, Yange Deng, Hikari Yai, Michihiro Mochida

Journal of Geophysical Research: Atmospheres Vol. 127 ( 19 ) 2022.10

Abundance, chemical structure, and light absorption properties of humic-like substances (HULIS) and other organic fractions of forest aerosols in Hokkaido Reviewed

Sonia Afsana, Ruichen Zhou, Yuzo Miyazaki, Eri Tachibana, Dhananjay Kumar Deshmukh, Kimitaka Kawamura, Michihiro Mochida

Scientific Reports Vol. 12 ( 1 ) 2022.8

Authorship：Last author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

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 PM<sub>0.95</sub> 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 (MAE<sub>365</sub>), 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.

DOI： 10.1038/s41598-022-18201-z

Web of Science

Other Link： https://www.nature.com/articles/s41598-022-18201-z

陸域生態系と大気化学

持田陸宏, 伊藤昭彦, 松田和秀, 谷晃

大気化学研究 ( 47 ) page： 047A05 2022.7

Offline analysis of the chemical composition and hygroscopicity of submicrometer aerosol at an Asian outflow receptor site and comparison with online measurements Reviewed

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 Vol. 22 page： 5515 - 5533 2022.5

Authorship：Last author,　Corresponding author Publisher：Copernicus GmbH

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.

DOI： 10.5194/acp-2021-704

Distinctive Sources Govern Organic Aerosol Fractions with Different Degrees of Oxygenation in the Urban Atmosphere Reviewed International coauthorship

Zhou Ruichen, Chen Qingcai, Chen Jing, Ren Lujie, Deng Yange, Vodicka Petr, Deshmukh Dhananjay K., Kawamura Kimitaka, Fu Pingqing, Mochida Michihiro

ENVIRONMENTAL SCIENCE & TECHNOLOGY Vol. 55 ( 8 ) page： 4494 - 4503 2021.4

紀伊半島の森林における大気エアロゾル粒子の生成・成長とその雲凝結核としての寄与 Invited Reviewed

持田陸宏

エアロゾル研究 Vol. 36 ( 1 ) page： 25 - 31 2021.3

Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan Reviewed

Nakagawa Maho, Nakayama Tomoki, Sasago Hiroshi, Kuruma Yuki, Yai Hikari, Ogawa Shuhei, Deng Yange, Mochida Michihiro, Matsumi Yutaka

AEROSOL AND AIR QUALITY RESEARCH Vol. 20 ( 11 ) page： 2474 - 2484 2020.11

Diurnal variation and size dependence of the hygroscopicity of organic aerosol at a forest site in Wakayama, Japan: their relationship to CCN concentrations

Deng Yange, Yai Hikari, Fujinari Hiroaki, Kawana Kaori, Nakayama Tomoki, Mochida Michihiro

ATMOSPHERIC CHEMISTRY AND PHYSICS Vol. 19 ( 9 ) page： 5889 - 5903 2019.5

Chemical transfer of dissolved organic matter from surface seawater to sea spray water-soluble organic aerosol in the marine atmosphere

Miyazaki Yuzo, Yamashita Youhei, Kawana Kaori, Tachibana Eri, Kagami Sara, Mochida Michihiro, Suzuki Koji, Nishioka Jun

SCIENTIFIC REPORTS Vol. 8 2018.10

Hygroscopicity of Organic Aerosols and Their Contributions to CCN Concentrations Over a Midlatitude Forest in Japan

Deng Yange, Kagami Sara, Ogawa Shuhei, Kawana Kaori, Nakayama Tomoki, Kubodera Ryo, Adachi Kouji, Hussein Tareq, Miyazaki Yuzo, Mochida Michihiro

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Vol. 123 ( 17 ) page： 9703-9723 2018.9

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 Mingfu, Tan Haobo, Chan Chak K., Mochida Michihiro, Hatakeyama Shiro, Kondo Yutaka, Schurman Misha I., Xu Hanbing, Li Fei, Shimada Kojiro, Li Liu, Deng Yange, Yai Hikari, Matsuki Atsushi, Qin Yiming, Zhao Jun

AEROSOL AND AIR QUALITY RESEARCH Vol. 17 ( 12 ) page： 3194-3208 2017.12

Structural and Light-Absorption Characteristics of Complex Water-Insoluble Organic Mixtures in Urban Submicrometer Aerosols

Chen Qingcai, Ikemori Fumikazu, Nakamura Yuua, Vodicka Petr, Kawamura Kimitaka, Mochida Michihiro

ENVIRONMENTAL SCIENCE & TECHNOLOGY Vol. 51 ( 15 ) page： 8293-8303 2017.8

Hygroscopicity and cloud condensation nucleus activity of forest aerosol particles during summer in Wakayama, Japan

Kawana Kaori, Nakayama Tomoki, Kuba Naomi, Mochida Michihiro

JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES Vol. 122 ( 5 ) page： 3042-3064 2017.3

Fungal spores overwhelm biogenic organic aerosols in a midlatitudinal forest Reviewed

Chunmao Zhu, Kimitaka Kawamura, Yasuro Fukuda, Michihiro Mochida, and Yoko Iwamoto

Atmospheric Chemistry and Physics Vol. 16 page： 7497-7506 2016.6

Hygroscopicity of aerosol particles and CCN activity of nearly-hydrophobic particles in the urban atmosphere over Japan during summer Reviewed

Shuhei Ogawa, Yoshitaka Setoguchi, Kaori Kawana, Tomoki Nakayama, Yuka Ikeda, Yuuki Sawada, Yutaka Matsumi, and Michihiro Mochida

Journal of Geophysical Research: Atmospheres Vol. 121 page： 7215-7234 2016.6

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Papers - MOCHIDA, Michihiro