Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan
Abstract The sphericity of particles must be considered when evaluating their effects on the climate and human health. Thus, to examine this property and its controlling factors, this study measured the scattering angular distributions of both thermodenuded and non-thermodenuded individual particles...
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| Format: | Article |
| Language: | English |
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Springer
2020-07-01
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| Series: | Aerosol and Air Quality Research |
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| Online Access: | https://doi.org/10.4209/aaqr.2020.01.0023 |
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| author | Maho Nakagawa Tomoki Nakayama Hiroshi Sasago Yuki Kuruma Hikari Yai Shuhei Ogawa Yange Deng Michihiro Mochida Yutaka Matsumi |
| author_facet | Maho Nakagawa Tomoki Nakayama Hiroshi Sasago Yuki Kuruma Hikari Yai Shuhei Ogawa Yange Deng Michihiro Mochida Yutaka Matsumi |
| author_sort | Maho Nakagawa |
| collection | DOAJ |
| description | Abstract The sphericity of particles must be considered when evaluating their effects on the climate and human health. Thus, to examine this property and its controlling factors, this study measured the scattering angular distributions of both thermodenuded and non-thermodenuded individual particles with a diameter of 500 nm in real time using a home-made polar nephelometer in Nagoya, Japan. Estimating the sphericities based on the depths of the local minima in the scattering angular distributions, we found the ambient aerosols to be external mixtures of at least two types of particles, one with relatively high and the other with relatively low sphericity. Although most of the particles exhibiting high sphericity were removed as they passed through the thermodenuder, approximately one-third of the fraction exhibiting low sphericity remained. During the daytime, the proportion of the low-sphericity particles decreased, whereas the average sphericity of the high-sphericity particles increased, which can be attributed to photochemical formation and/or aging processes. On days with extremely high relative humidity, the diurnal variation in the average sphericity displayed another peak during the early morning, which may have been due to the secondary formation of nitrate. |
| format | Article |
| id | doaj-art-430059c566b64a269b48f94ee19e6d6e |
| institution | Kabale University |
| issn | 1680-8584 2071-1409 |
| language | English |
| publishDate | 2020-07-01 |
| publisher | Springer |
| record_format | Article |
| series | Aerosol and Air Quality Research |
| spelling | doaj-art-430059c566b64a269b48f94ee19e6d6e2025-02-09T12:19:16ZengSpringerAerosol and Air Quality Research1680-85842071-14092020-07-0120112474248410.4209/aaqr.2020.01.0023Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in JapanMaho Nakagawa0Tomoki Nakayama1Hiroshi Sasago2Yuki Kuruma3Hikari Yai4Shuhei Ogawa5Yange Deng6Michihiro Mochida7Yutaka Matsumi8Institute for Space-Earth Environmental Research, Nagoya UniversityInstitute for Space-Earth Environmental Research, Nagoya UniversityInstitute for Space-Earth Environmental Research, Nagoya UniversityInstitute for Space-Earth Environmental Research, Nagoya UniversityGraduate School of Environmental Studies, Nagoya UniversityGraduate School of Environmental Studies, Nagoya UniversityGraduate School of Environmental Studies, Nagoya UniversityInstitute for Space-Earth Environmental Research, Nagoya UniversityInstitute for Space-Earth Environmental Research, Nagoya UniversityAbstract The sphericity of particles must be considered when evaluating their effects on the climate and human health. Thus, to examine this property and its controlling factors, this study measured the scattering angular distributions of both thermodenuded and non-thermodenuded individual particles with a diameter of 500 nm in real time using a home-made polar nephelometer in Nagoya, Japan. Estimating the sphericities based on the depths of the local minima in the scattering angular distributions, we found the ambient aerosols to be external mixtures of at least two types of particles, one with relatively high and the other with relatively low sphericity. Although most of the particles exhibiting high sphericity were removed as they passed through the thermodenuder, approximately one-third of the fraction exhibiting low sphericity remained. During the daytime, the proportion of the low-sphericity particles decreased, whereas the average sphericity of the high-sphericity particles increased, which can be attributed to photochemical formation and/or aging processes. On days with extremely high relative humidity, the diurnal variation in the average sphericity displayed another peak during the early morning, which may have been due to the secondary formation of nitrate.https://doi.org/10.4209/aaqr.2020.01.0023Polar nephelometerScattering angular distributionSingle particleParticle sphericity |
| spellingShingle | Maho Nakagawa Tomoki Nakayama Hiroshi Sasago Yuki Kuruma Hikari Yai Shuhei Ogawa Yange Deng Michihiro Mochida Yutaka Matsumi Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan Aerosol and Air Quality Research Polar nephelometer Scattering angular distribution Single particle Particle sphericity |
| title | Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan |
| title_full | Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan |
| title_fullStr | Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan |
| title_full_unstemmed | Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan |
| title_short | Assessment of the Sphericity of Submicrometer Particles Using a Single-particle Polar Nephelometer at an Urban Site in Japan |
| title_sort | assessment of the sphericity of submicrometer particles using a single particle polar nephelometer at an urban site in japan |
| topic | Polar nephelometer Scattering angular distribution Single particle Particle sphericity |
| url | https://doi.org/10.4209/aaqr.2020.01.0023 |
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