[A-AS22_1AM2] 大気化学

[AAS22-20] 民間航空機によって観測された上部対流圏/下部成層圏温室効果気体の季節変化

*澤 庸介¹、町田 敏暢²、松枝 秀和¹、丹羽 洋介¹、坪井 一寛¹、村山 昌平³、森本 真司⁴、青木 周司⁴ (1.気象研究所、2.国立環境研究所、3.産業技術総合研究所、4.東北大学)

キーワード：大気化学, 温室効果気体, 上部対流圏・下部成層圏

Atmospheric mixing ratios of greenhouse gases at about 11 km altitude were analyzed from monthly air sampling aboard commercial airliner during the flights between Europe and Japan from April 2012 to August 2013. Compared to the subtropic, higher CH4 and SF6 mixing ratios, similar values of N2O, and larger seasonal changes of CO2 were found in the upper troposphere. CH4, N2O and SF6 in the lower stratosphere, above the tropopause up to 30 K in potential temperature, showed simultaneous increases from June to October, and faster decreases at higher altitudes from January to March. Mean age of the air in the lower stratosphere was estimated based on SF6 mixing ratios to be about 2 years in late spring and 1 year in autumn, suggesting stronger influences on the mixing ratios in the stratosphere from troposphere in summer.