日本地球惑星科学連合2018年大会

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[EJ] 口頭発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS06] 大気化学

2018年5月24日(木) 13:45 〜 15:15 A05 (東京ベイ幕張ホール)

コンビーナ:岩本 洋子(広島大学 生物圏科学研究科)、中山 智喜(長崎大学 大学院水産・環境科学総合研究科)、豊田 栄(東京工業大学物質理工学院、共同)、江口 菜穂(Kyushu University)、座長:峰島 知芳(国際基督教大学)、滝川 雅之(国立研究開発法人 海洋研究開発機構)

14:15 〜 14:30

[AAS06-18] Analysis of springtime high ozone events at Mt. Happo from 2014 to 2016

*岡本 祥子1谷本 浩志1奈良 英樹1北 和之2Putero Davide3 (1.国立環境研究所、2.茨城大学、3.National Research Council of Italy)

キーワード:対流圏オゾン、一酸化炭素、STEFLUX、長距離輸送

Tropospheric ozone (O3) is one of the most important trace gases in the Earth’s atmosphere because it plays a central role in determining the oxidizing capacity of the atmosphere and air quality at local, regional, and global scales. Long-term trend of springtime O3 at Mt. Happo (HPO; 36.70°N, 137.80°E, 1850 m a.s.l.) has been controlled by the El Niño Southern Oscillation (ENSO) as well as precursor emissions (Okamoto et al., submitted). Therefore, it is important to analyze long-range transport pattern changes induced by meteorological condition changes. In this study, we examine springtime O3 enhancement events observed at HPO for the period from 2014 to 2016 focusing on its sources, characteristics of atmospheric composition and meteorological condition. HPO is located in the mountainous area near the Sea of Japan coast, and is one of the contribution site for the Acid Deposition Monitoring Network in East Asia (EANET) program. Surface O3 has been measured by using UV absorption instrument since April 1998. In addition, we started measuring CO, CO2 and CH4 by using a Cavity Ring-Down Spectrometer since July 2013. To examine the origins and transport pathways of large-scale air masses arriving at HPO, 5-day backward trajectories were calculated using the NOAA Hybrid Single-Particle Lagrangian Trajectory (HYSPLIT, Version 4) model. We used STEFLUX (Putero et al., 2016) for evaluation of the effect of stratosphere-to-troposphere exchange (STE) on O3 concentration at HPO. Our results indicate that STE has not significantly influenced on springtime O3 concentrations at HPO, however STE is important source for tropospheric springtime O3 in the Northern Hemisphere at mid-latitudes. We calculate the residence time over the source regions by using back trajectory analysis. In the presentation, we will show the potential source regions, enhancement ratios and meteorological condition for individual O3 enhancement event.