Evaluation of global warming based on a precise observation of the atmospheric Ar/N2 ratio

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H02814
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Ishidoya Shigeyuki 国立研究開発法人産業技術総合研究所, 環境管理研究部門, 研究グループ付 (70374907)
• Co-Investigator(Kenkyū-buntansha): 遠嶋 康徳 国立研究開発法人国立環境研究所, 環境計測研究センター, 室長 (40227559) ; 坪井 一寛 気象庁気象研究所, 海洋・地球化学研究部, 主任研究官 (10553167) ; 後藤 大輔 国立極地研究所, 研究教育系, 助教 (10626386) ; 丹羽 洋介 気象庁気象研究所, 海洋・地球化学研究部, 主任研究官 (70588318) ; 村山 昌平 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 総括研究主幹 (30222433) ; 田口 彰一 国立研究開発法人産業技術総合研究所, 環境管理研究部門, 上級主任研究員 (10357395)
• Co-Investigator(Renkei-kenkyūsha): MATSUEDA Hidekazu 気象庁気象研究所, 海洋地球化学研究部, 室長 (60354552) ; MORIMOTO Shinji 東北大学, 理学研究科, 教授 (30270424)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 大気中アルゴン濃度 / 海洋貯熱量 / 地球温暖化

Outline of Final Research Achievements

Variations in the atmospheric Ar/N2 ratio at the surface are driven principally by air-sea Ar and N2 fluxes due to changes in solubility, and the Ar/N2 ratio is expected to be a unique tracer for spatiotemporally-integrated air-sea heat flux. We have conducted observations of the Ar/N2 ratio at Tsukuba, Hateruma Island, Cape Ochi-ishi, Takayama, Minamitorishima Island, Japan and at Syowa, Antarctica. The measurement system employing a mass spectrometer was used not only for the continuous observations at Tsukuba but also for the analyses of the air samples collected in flasks at other sites. We found clear seasonal Ar/N2 cycles with summertime maxima at all sites and year-to-year variations in the Ar/N2 ratio, derived from 5-years data at Tsukuba and Hateruma, generally in phase with the variations in the global ocean heat content reported by NOAA/NODC. These facts suggest that the Ar/N2 ratio observed in this study reflected wide-area ocean temperature changes.

Free Research Field

大気科学