Ice shelf - sea ice- ocean interaction in East Antarctica

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H04710
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: National Institute of Polar Research
• Principal Investigator: Tamura Takeshi 国立極地研究所, 研究教育系, 准教授 (40451413)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 南極 / 氷床-海氷-海洋相互作用 / 定着氷 / 氷床・棚氷融解

Outline of Final Research Achievements

It is very important to have a clear understanding of how Antarctic continental ice is melting, and to more accurately predict sea level fluctuations. This study combined in-situ oceanic observation results around Shirase Glacier Tongue in Lutzow-Holm Bay, East Antarctica, with wind data, ice radar measurements, and computer modelling to understand ocean circulation underneath the Shirase Glacier Tongue. The melting is occurring as a result of deep and warm water flowing inwards towards the base of the Shirase Glacier Tongue. Warm water flows into Lutzow-Holm Bay along a deep underwater ocean trough and then flows upwards along the base of the tongue, warming and melting the base of Shirase Glacier Tongue. This melting occurs year-round, but is affected by easterly, alongshore winds that vary seasonally. When the winds diminish in the summer, the influx of the deep warm water increases, speeding up the melting rate.

Free Research Field

極域海洋学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、日本として初めて、海洋による南極氷床の融解プロセスを示した観測研究成果であるとともに、西南極と比べて圧倒的に知見が乏しい東南極における氷床質量変動の理解向上に貢献すると期待される。また、南極沿岸域を網羅的に観測することは現実的に不可能な中、沖合循環と氷床の位置関係で融解強度が決定されることを示唆した本研究の成果は、東南極沿岸域における優先的な観測域の決定にも貢献すると考えらる。