Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6339845 | Atmospheric Environment | 2014 | 9 Pages |
Abstract
Aerial observations of atmospheric pollutants were made over the East China Sea to analyze the transport of air pollutants, especially nitrogen oxides, from East Asia. Three flights each were conducted in October 2009 (autumn) and December 2010 (winter). Onboard measurements of gaseous total odd nitrogen species, gaseous nitric acid (HNO3(g)), O3, SO2, CO and black carbon were made and particles were collected on filters for ionic and metal component analyses. The NO3â(p)/T.NO3 (T.NO3 = HNO3(g) + NO3â(p); NO3â(p) indicates particulate nitrate) ratios were less than 0.5 in most cases. Exceptions were 17 October and 11 December, when high concentrations of dust particles (Kosa) were transported. The average T.NO3/NOy (NOy indicates total odd nitrogen species) ratio in winter was 0.59, and that in autumn was 0.71. In addition, positive and negative correlations between NOy â T.NO3 and ozone were observed in autumn and winter, respectively. These results indicate that the main components of NOy â T.NO3 are NOx and its descendant photochemical products, such as peroxyacyl nitrates and alkyl nitrates, in winter and autumn, respectively. Ratios of Na+ to Clâ + NO3â in particles were close to the seawater ratio for observations in both autumn and winter, save for the Kosa events. The main NO3â(p) formation process was the reaction of HNO3(g) with sea salt aerosols during autumn and winter. On the other hand, NO3â(p) was generated by the reaction of HNO3(g) with dust particles and sea salt during the Kosa events. The fraction of NH4NO3 in NO3â(p) was very small.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Hiroshi Fujiwara, Yasuhiro Sadanaga, Junki Urata, Yoshihiko Masui, Hiroshi Bandow, Keisuke Ikeda, Sayuri Hanaoka, Izumi Watanabe, Takemitsu Arakaki, Shungo Kato, Yoshizumi Kajii, Daizhou Zhang, Kazutaka Hara, Toshiyuki Fujimoto, Takafumi Seto,