2024-03-29T11:09:32Z
https://u-ryukyu.repo.nii.ac.jp/oai
oai:u-ryukyu.repo.nii.ac.jp:02019361
2023-08-03T05:37:50Z
1642838163960:1642838338003
1642838403551:1642838406414
Contributions of Long-Range Transported and Locally Emitted Nitrate in Size-Segregated Aerosols in Japan at Kyushu and Okinawa
Tatsuta, Shiori
Shimada, Kojiro
Chan, K. Chak
Kim, Pyo Yong
Lin, Neng-Huei
Takami, Akinori
Hatakeyama, Shiro
open access
© Taiwan Association for Aerosol Research
the Creative Commons Attribution 4.0 License (CC BY 4.0)
Nitrate
Transport of fine nitrate
East Asia
Contribution of long-range transport and local air pollution
We observed the size distributions of mass concentration, ionic composition, and trace metal concentration in aerosols collected at an urban site in Kumamoto Prefecture (KM) and a rural site at Cape Hedo in Okinawa Prefecture (HD) between 2012 and 2015. To evaluate the contribution of transboundary nitrate and locally emitted nitrate in the aerosols at Kumamoto, we distinguished between days of transboundary air pollution from East Asia and days of local air pollution on the basis of a threshold for Pb concentration and the ratio Pb (in 0.5 < projected area diameter (Dp) < 1.0 µm)/Cu (in 2.5 < Dp < 10 µm). Fine nitrate (particulate NH_4NO_3) did not arrive at HD from the Asian continent even under long-range transport conditions. Fine nitrate emitted in Kumamoto and its vicinity also was not transported to HD, even in an air mass that passed over KM and reached HD within one day. Almost all fine nitrate was converted to coarse nitrate during transport by dissociation of fine nitrate and adsorption of HNO_3 on larger aerosol particles. Transboundary nitrate existed largely in the particle size range of 0.5 < Dp < 10 µm, and the contribution of transboundary nitrate in the particle size range of 0.1 < Dp < 0.5 µm was about 20% even under long-range transport conditions. The contribution of transboundary nitrate in particles with Dp < 2.5 µm at KM was approximately 50%, 50%, and 80% in spring, autumn, and winter, respectively.
Taiwan Association for Aerosol Research
2017-12
eng
journal article
VoR
http://hdl.handle.net/20.500.12000/0002019361
https://u-ryukyu.repo.nii.ac.jp/records/2019361
https://doi.org/10.4209/aaqr.2016.12.0587
1680-8584
2071-1409
Aerosol and Air Quality Research
17
12
3119
3127
https://u-ryukyu.repo.nii.ac.jp/record/2019361/files/aaqr-16-12-lrt-0587.pdf
548 KB