日本地球惑星科学連合2022年大会

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[J] 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-AS11] 大気化学

2022年5月27日(金) 15:30 〜 17:00 201A (幕張メッセ国際会議場)

コンビーナ:内田 里沙(一般財団法人 日本自動車研究所)、コンビーナ:坂本 陽介(京都大学大学院地球環境学堂)、岩本 洋子(広島大学大学院統合生命科学研究科)、コンビーナ:石戸谷 重之(産業技術総合研究所)、座長:内田 里沙(一般財団法人 日本自動車研究所)、坂本 陽介(京都大学大学院地球環境学堂)

16:30 〜 16:45

[AAS11-21] New particle formation promoted by OH reactions during α-pinene ozonolysis

*猪俣 敏1 (1.国立研究開発法人国立環境研究所)

キーワード:α-ピネンのオゾン反応、自動酸化、酸素を多く含む化合物、新粒子生成、粒子核、二次有機エアロゾル

Monoterpenes have been reported to rapidly convert to extremely low volatility organic compounds (ELVOCs), which can act as nucleation agents leading to new particle formation (NPF). The formation of highly oxygenated organic molecules (HOMs) via autoxidation is proposed to be a key process of the NPF in the monoterpene oxidation, but the mechanism has not yet been established. In this study, the size distribution of the number concentration of secondary organic aerosol (SOA) from α-pinene ozonolysis in the presence of seed particles was investigated. In the absence of the OH radical scavenger, this distribution was found to be bimodal. The peak arising from small particles was a result of NPF; however, when the OH radical scavenger was present in the experiment, this peak disappeared. Owing to the bimodal size distribution of SOA from limonene ozonolysis with the OH radical scavenger and seed particles, it was proposed that addition of the OH radical to the α-pinene double bond followed by isomerization, which accompanies ring opening, generating limonene-like compounds, could be one of the key steps in producing ELVOCs as nucleating agents during α-pinene ozonolysis.