Investigation on the role of ocean waves in sea ice structuring from formation to break up stages

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H00801
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Waseda Takuji 東京大学, 大学院新領域創成科学研究科, 教授 (30376488)
• Co-Investigator(Kenkyū-buntansha): 松沢 孝俊 国立研究開発法人海上・港湾・航空技術研究所, その他部局等, 研究員 (00443242) ; 小平 翼 東京大学, 大学院新領域創成科学研究科, 講師 (60795459)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 海氷波浪相互作用 / 氷海水槽実験 / マージナルアイスゾーン / 氷盤フラクタル / 波浪方向スペクトル

Outline of Final Research Achievements

The aim of the research is to investigate and model the dynamical processes of wave-ice interactions in the marginal ice zone from the generation to the breakup of the sea ice by waves, and the propagation and attenuation of waves under ice. For that, the new wave ice tank and the newly developed method to create frazil ice under waves were used to create different types of freshwater ice. Wave propagation and attenuation under different ice field, the resulting ice group formation process, and the nonlinear wave evolutions were studied. Field expeditions were conducted in the Okhotsk Sea, Arctic Ocean and Antarctic Ocean where an anomalous spectral downshift was observed in the Okhotsk Sea. Finally, a subgrid scale model to estimate the nonlinear wave-wave interactions under ice was developed. Also, a numerical wave-ice tank is being developed to mimic the physical wave-ice tank.

Free Research Field

Ocean Information

Academic Significance and Societal Importance of the Research Achievements

国内には現在稼働中の氷海水槽は一つしかなく、民間企業にて砕氷船の設計のために用いられている。本研究では海洋研究開発機構が建造した水槽に造波機を設置し、国内唯一の氷海波浪水槽を東京大学柏キャンパスに構築した。水槽実験や、北極・南極・オホーツク海での観測は教育効果も高く、北極海航路開発、北極域研究船による観測研究につながる。