Intensive study of the Antarctic tropopause region based on high-resolution observations

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H04578
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: National Institute of Polar Research
• Principal Investigator: Tomikawa Yoshihiro 国立極地研究所, 研究教育系, 准教授 (20435499)
• Co-Investigator(Kenkyū-buntansha): 佐藤 薫 東京大学, 大学院理学系研究科(理学部), 教授 (90251496) ; 平沢 尚彦 国立極地研究所, 研究教育系, 助教 (10270422) ; 高麗 正史 東京大学, 大学院理学系研究科(理学部), 助教 (80733550)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 南極 / 対流圏界面 / 水蒸気

Outline of Final Research Achievements

The tropopause region (around 10 km altitude) is a region where the distribution of temperature and chemical constituents (ozone, water vapor, etc.) changes abruptly with altitude, and thus requires high-vertical resolution data for research. In the Antarctic region, where weather conditions are harsh and transportation of supplies and personnel is limited, sufficient observations have not been conducted to date. In this study, we have conducted continuous observations at Syowa Station in Antarctica using a balloon-borne hygrometer, which can measure water vapor in the tropopause region with high precision, and obtained a large number of data. The results also revealed that the water vapor enhancement in the upper troposphere was caused by water vapor transport along an atmospheric river, which represents the horizontal water vapor transport path.

Free Research Field

中層大気科学

Academic Significance and Societal Importance of the Research Achievements

南極における水蒸気ゾンデ観測は、地球温暖化にも影響する上部対流圏・下部成層圏の水蒸気量を高精度で測定することができます。本研究では、同観測で得られた上部対流圏の水蒸気増大が、atmospheric riverと呼ばれる水蒸気輸送経路に沿って輸送されてきたことを示しました。今後、南極域への水蒸気輸送を定量的に明らかにすることは、南極氷床の総量を左右する涵養過程の定量化につながると期待されます。