日本地球惑星科学連合2016年大会

講演情報

インターナショナルセッション(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-AS01] Global Carbon Cycle Observation and Analysis

2016年5月24日(火) 13:45 〜 15:15 A03 (アパホテル&リゾート 東京ベイ幕張)

コンビーナ:*三枝 信子(国立環境研究所)、Patra Prabir(Research Institute for Global Change, JAMSTEC)、町田 敏暢(国立環境研究所)、茶谷 聡(国立環境研究所)、座長:町田 敏暢(国立環境研究所)

15:00 〜 15:15

[AAS01-06] Fine-scale CO2 variations over the Tokyo megacity observed by CONTRAIL

*梅澤 拓1松枝 秀和2町田 敏暢1澤 庸介2丹羽 洋介2 (1.独立行政法人国立環境研究所、2.気象庁気象研究所)

キーワード:Megacity, CO2, Aircraft measurements

Urban areas are considered to account for ~70% of the global anthropogenic carbon emissions. Many cities now take actions to reduce their carbon emissions. However, atmospheric CO2 measurement networks capable of verifying carbon emissions from large cities are still far from sufficient. CONTRAIL, an ongoing project to measure trace gases with instruments onboard aircraft of Japan Airlines, has obtained millions of CO2 data over worldwide large cities since 2005. In general, we have observed increases of CO2 concentration approaching down to the airports, indicating presence of CO2 plume over metropolitan areas. We found vertical gradient of CO2 concentration (i.e. difference between the free troposphere and the lowermost layer) larger for large megacities, suggesting that CO2 plume correlates with size of the city. This infers that the CONTRAIL measurements may have potential to assess city’s carbon emission trends. In this study, we focus on detailed analysis of CO2 distributions over Tokyo, currently the world largest megacity. Analyzing thousands of vertical profiles of CO2 over the Narita and Haneda airports over the last 10 years, we found CO2 levels significantly different between areas over Haneda and north and south of Narita. This likely reflects different catchments of CO2 plumes over the respective areas.