2024-03-29T09:19:34Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00028396
2023-01-16T04:21:06Z
488:489:490
Vehicular exhaust contributions to high NH3 and PM2.5 concentrations during winter in Tokyo, Japan
Osada, Kazuo
92911
Saito, Shinji
92912
Tsurumaru, Hiroshi
92913
Hoshi, Junya
92914
Concentrations of PM2.5 in Tokyo, a densely populated megacity, often increase because of NH4NO3 formation under low-wind conditions during winter. To obtain source information of NH3 as a NH4NO3 precursor, hourly NH3 and NH4^+ concentrations were measured at an urban site in Tokyo in December 2017. Results show that PM2.5 and NH4^+ concentrations increased simultaneously under low-wind and low-temperature conditions along with NH3, NOx, CO, and optical black carbon (OBC) concentrations. The remaining NH4^+ (herein, ΔNH4^+) subtracted from observed NH4^+ to equivalent SO4^2− concentration correlated well with NO3^− in PM2.5, indicating the existence of fine NH4NO3 particles. Regression analysis of hourly NH3 + ΔΝH4^+ concentrations with CO, NOx, and OBC showed significant correlation. Virtual emission rates (VER) of NH3 per motor vehicle in Tokyo were estimated using observed relations between NH3 + ΔΝH4^+ and OBC, etc. with data from vehicular statistics: they were 3.7–32 mg/km. The regression of NH3 + ΔΝH4^+ with OBC concentrations indicated an intercept of about 3.2 ppb, which is about half of the monthly average in December. This result implies that the non-vehicular source strength was nearly the same strength as the bulk vehicular emissions of NH3 during winter in Tokyo.
ファイル公開:2021-06-01
journal article
Elsevier
2019-06-01
application/pdf
Atmospheric Environment
206
218
224
1352-2310
https://nagoya.repo.nii.ac.jp/record/28396/files/Osada_Vehicular_exhaust_contributions.pdf
eng
https://doi.org/10.1016/j.atmosenv.2019.03.008
© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/