Nitrate transboundary heavy pollution over East Asia in winter
High PM<sub>2. 5</sub> concentrations of around 100 µg m<sup>−3</sup> were observed twice during an intensive observation campaign in January 2015 at Fukuoka (33.52° N, 130.47° E) in western Japan. These events were analyzed comprehensively with a regional chemical transport...
Main Authors: | , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-03-01
|
Series: | Atmospheric Chemistry and Physics |
Online Access: | http://www.atmos-chem-phys.net/17/3823/2017/acp-17-3823-2017.pdf |
id |
doaj-2af32d7c2c1e410c8dfb6445d3234860 |
---|---|
record_format |
Article |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
S. Itahashi I. Uno K. Osada Y. Kamiguchi S. Yamamoto K. Tamura Z. Wang Y. Kurosaki Y. Kanaya |
spellingShingle |
S. Itahashi I. Uno K. Osada Y. Kamiguchi S. Yamamoto K. Tamura Z. Wang Y. Kurosaki Y. Kanaya Nitrate transboundary heavy pollution over East Asia in winter Atmospheric Chemistry and Physics |
author_facet |
S. Itahashi I. Uno K. Osada Y. Kamiguchi S. Yamamoto K. Tamura Z. Wang Y. Kurosaki Y. Kanaya |
author_sort |
S. Itahashi |
title |
Nitrate transboundary heavy pollution over East Asia in winter |
title_short |
Nitrate transboundary heavy pollution over East Asia in winter |
title_full |
Nitrate transboundary heavy pollution over East Asia in winter |
title_fullStr |
Nitrate transboundary heavy pollution over East Asia in winter |
title_full_unstemmed |
Nitrate transboundary heavy pollution over East Asia in winter |
title_sort |
nitrate transboundary heavy pollution over east asia in winter |
publisher |
Copernicus Publications |
series |
Atmospheric Chemistry and Physics |
issn |
1680-7316 1680-7324 |
publishDate |
2017-03-01 |
description |
High PM<sub>2. 5</sub> concentrations of around
100 µg m<sup>−3</sup> were observed twice during an intensive
observation campaign in January 2015 at Fukuoka (33.52° N,
130.47° E) in western Japan. These events were analyzed
comprehensively with a regional chemical transport model and synergetic
ground-based observations with state-of-the-art measurement systems, which
can capture the behavior of secondary inorganic aerosols (SO<sub>4</sub><sup>2−</sup>,
NO<sub>3</sub><sup>−</sup>, and NH<sub>4</sub><sup>+</sup>). The first episode of high PM<sub>2. 5</sub>
concentration was dominated by NO<sub>3</sub><sup>−</sup> (type N) and the second episode
by SO<sub>4</sub><sup>2−</sup> (type S). The concentration of NH<sub>4</sub><sup>+</sup> (the counterion
for SO<sub>4</sub><sup>2−</sup> and NO<sub>3</sub><sup>−</sup>) was high for both types. A sensitivity
simulation in the chemical transport model showed that the dominant
contribution was from transboundary air pollution for both types. To
investigate the differences between these types further, the chemical
transport model results were examined, and a backward trajectory analysis was
used to provide additional information. During both types of episodes, high
concentrations of NO<sub>3</sub><sup>−</sup> were found above China, and an air mass that
originated from northeast China reached Fukuoka. The travel time from the
coastline of China to Fukuoka differed between types: it was 18 h for type N
and 24 h for type S. The conversion ratio of SO<sub>2</sub> to SO<sub>4</sub><sup>2−</sup>
(<i>F</i><sub>s</sub>) was less than 0.1 for type N, but reached 0.3 for type S as
the air mass approached Fukuoka. The higher <i>F</i><sub>s</sub> for type S was
related to the higher relative humidity and the concentration of HO<sub>2</sub>,
which produces H<sub>2</sub>O<sub>2</sub>, the most effective oxidant for the
aqueous-phase production of SO<sub>4</sub><sup>2−</sup>. Analyzing the gas ratio as an
indicator of the sensitivity of NO<sub>3</sub><sup>−</sup> to changes in SO<sub>4</sub><sup>2−</sup> and
NH<sub>4</sub><sup>+</sup> showed that the air mass over China was NH<sub>3</sub>-rich for
type N, but almost NH<sub>3</sub>-neutral for type S. Thus, although the high
concentration of NO<sub>3</sub><sup>−</sup> above China gradually decreased during
transport from China to Fukuoka, higher NO<sub>3</sub><sup>−</sup> concentrations were
maintained during transport owing to the lower SO<sub>4</sub><sup>2−</sup> for type N. In
contrast, for type S, the production of SO<sub>4</sub><sup>2−</sup> led to the
decomposition of NH<sub>4</sub>NO<sub>3</sub>, and more SO<sub>4</sub><sup>2−</sup> was transported.
Notably, the type N transport pattern was limited to western Japan,
especially the island of Kyushu. Transboundary air pollution dominated by
SO<sub>4</sub><sup>2−</sup> (type S) has been recognized as a major pattern of pollution
over East Asia. However, our study confirms the importance of transboundary
air pollution dominated by NO<sub>3</sub><sup>−</sup>, which will help refine our
understanding of transboundary heavy PM<sub>2. 5</sub> pollution in winter over East
Asia. |
url |
http://www.atmos-chem-phys.net/17/3823/2017/acp-17-3823-2017.pdf |
work_keys_str_mv |
AT sitahashi nitratetransboundaryheavypollutionovereastasiainwinter AT iuno nitratetransboundaryheavypollutionovereastasiainwinter AT kosada nitratetransboundaryheavypollutionovereastasiainwinter AT ykamiguchi nitratetransboundaryheavypollutionovereastasiainwinter AT syamamoto nitratetransboundaryheavypollutionovereastasiainwinter AT ktamura nitratetransboundaryheavypollutionovereastasiainwinter AT zwang nitratetransboundaryheavypollutionovereastasiainwinter AT ykurosaki nitratetransboundaryheavypollutionovereastasiainwinter AT ykanaya nitratetransboundaryheavypollutionovereastasiainwinter |
_version_ |
1725242064252174336 |
spelling |
doaj-2af32d7c2c1e410c8dfb6445d32348602020-11-25T00:52:30ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-03-011763823384310.5194/acp-17-3823-2017Nitrate transboundary heavy pollution over East Asia in winterS. Itahashi0I. Uno1K. Osada2Y. Kamiguchi3S. Yamamoto4K. Tamura5Z. Wang6Y. Kurosaki7Y. Kanaya8Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba 270-1194, JapanResearch Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga Park, Kasuga, Fukuoka 816-8580, JapanGraduate School of Environmental Studies, Nagoya University, D2-1 (510) Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, JapanGraduate School of Environmental Studies, Nagoya University, D2-1 (510) Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, JapanFukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135, JapanNagasaki Prefectural Environmental Affairs Department, 2-1306-11 Ikeda, Omura, Nagasaki 856-0026, JapanResearch Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga Park, Kasuga, Fukuoka 816-8580, JapanArid Land Research Center, Tottori University, 1390 Hamasaka, Tottori 680-0001, JapanJapan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, JapanHigh PM<sub>2. 5</sub> concentrations of around 100 µg m<sup>−3</sup> were observed twice during an intensive observation campaign in January 2015 at Fukuoka (33.52° N, 130.47° E) in western Japan. These events were analyzed comprehensively with a regional chemical transport model and synergetic ground-based observations with state-of-the-art measurement systems, which can capture the behavior of secondary inorganic aerosols (SO<sub>4</sub><sup>2−</sup>, NO<sub>3</sub><sup>−</sup>, and NH<sub>4</sub><sup>+</sup>). The first episode of high PM<sub>2. 5</sub> concentration was dominated by NO<sub>3</sub><sup>−</sup> (type N) and the second episode by SO<sub>4</sub><sup>2−</sup> (type S). The concentration of NH<sub>4</sub><sup>+</sup> (the counterion for SO<sub>4</sub><sup>2−</sup> and NO<sub>3</sub><sup>−</sup>) was high for both types. A sensitivity simulation in the chemical transport model showed that the dominant contribution was from transboundary air pollution for both types. To investigate the differences between these types further, the chemical transport model results were examined, and a backward trajectory analysis was used to provide additional information. During both types of episodes, high concentrations of NO<sub>3</sub><sup>−</sup> were found above China, and an air mass that originated from northeast China reached Fukuoka. The travel time from the coastline of China to Fukuoka differed between types: it was 18 h for type N and 24 h for type S. The conversion ratio of SO<sub>2</sub> to SO<sub>4</sub><sup>2−</sup> (<i>F</i><sub>s</sub>) was less than 0.1 for type N, but reached 0.3 for type S as the air mass approached Fukuoka. The higher <i>F</i><sub>s</sub> for type S was related to the higher relative humidity and the concentration of HO<sub>2</sub>, which produces H<sub>2</sub>O<sub>2</sub>, the most effective oxidant for the aqueous-phase production of SO<sub>4</sub><sup>2−</sup>. Analyzing the gas ratio as an indicator of the sensitivity of NO<sub>3</sub><sup>−</sup> to changes in SO<sub>4</sub><sup>2−</sup> and NH<sub>4</sub><sup>+</sup> showed that the air mass over China was NH<sub>3</sub>-rich for type N, but almost NH<sub>3</sub>-neutral for type S. Thus, although the high concentration of NO<sub>3</sub><sup>−</sup> above China gradually decreased during transport from China to Fukuoka, higher NO<sub>3</sub><sup>−</sup> concentrations were maintained during transport owing to the lower SO<sub>4</sub><sup>2−</sup> for type N. In contrast, for type S, the production of SO<sub>4</sub><sup>2−</sup> led to the decomposition of NH<sub>4</sub>NO<sub>3</sub>, and more SO<sub>4</sub><sup>2−</sup> was transported. Notably, the type N transport pattern was limited to western Japan, especially the island of Kyushu. Transboundary air pollution dominated by SO<sub>4</sub><sup>2−</sup> (type S) has been recognized as a major pattern of pollution over East Asia. However, our study confirms the importance of transboundary air pollution dominated by NO<sub>3</sub><sup>−</sup>, which will help refine our understanding of transboundary heavy PM<sub>2. 5</sub> pollution in winter over East Asia.http://www.atmos-chem-phys.net/17/3823/2017/acp-17-3823-2017.pdf |