Observational study of turbulent heat and near-inertial internal waves under perennial sea ice in the Arctic Ocean: Assessment of the global warming

2021 Fiscal Year Final Research Report

• Project/Area Number: 17KK0083
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: The University of Tokyo
• Principal Investigator: Kawaguchi Yusuke 東京大学, 大気海洋研究所, 助教 (00554114)
• Project Period (FY): 2018 – 2021
• Keywords: 北極海 / 海氷変動 / 地球温暖化 / 熱収支 / 乱流混合 / 内部重力波

Outline of Final Research Achievements

For the aim of the assessment of global warming and its implication in the Arctic environment, we participated in the international joint project , MOSAiC, that is led by a German institution. In the project, we took samples of physical oceanographic parameters base on the drifting-ice platform using an ice breaking vessel, R/V Polarstern. In the field survey of ice ocean boundary layer of the Arctic Ocean, movement of water and heat were measured at high-frequency sampling rate. The observation revealed that in the surface water the low salinity melt-water plays important roles in regaining ice formation during winter season. That is, the freshened water is lowered in freezing temperature, and consequently it allows the water to freeze up in relatively mild cooling event in the atmosphere.

Free Research Field

海洋物理

Academic Significance and Societal Importance of the Research Achievements

北極海で進行している海氷量の変動（主に減少）は、地球温暖化のグローバルな影響を示す上でもっとも象徴的な事象と言えます。今後の北極海の海氷変動を予測する上で、現場調査から得られる知見はもっとも重要な鍵となります。本研究では、ドイツの砕氷船（Polarstern号）を用いた国際的な観測プロジェクト「MOSAiC」に参加することで、海氷と海洋の間で起きる熱や運動量のやりとりに注目し、海氷変動の実態を明らかにするための現地調査を行いました。