Turbulent mixing of momentum due to Langmuir circulation: Field and numerical experiments

2016 Fiscal Year Final Research Report

• Project/Area Number: 25287123
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Kyoto University
• Principal Investigator: Yoshikawa Yutaka 京都大学, 理学(系)研究科(研究院), 准教授 (40346854)
• Co-Investigator(Renkei-kenkyūsha): Baba Yasuyuki 京都大学, 防災研究所, 准教授 (30283675) ; Mizutani Hideaki 京都大学, 防災研究所, 助手 (00636756)
• Research Collaborator: Yufu Kei 九州大学, 応用力学研究所, 技術職員 ; Ushijima Yusuke 京都大学, 大学院理学研究科 ; Fujiwara Yasushi 京都大学, 大学院理学研究科 ; Mannen Takahiro 京都大学, 大学院理学研究科
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 海洋表層混合 / ラングミュア循環

Outline of Final Research Achievements

Field experiments of turbulent velocities were conducted in order to reveal Langmuir circulation, a potential ingredient of ocean surface mixing. Coherent structures of Langmuir circulation were successfully captured in our field experiments. Observed turbulence was intense when surface waves, a driver of Langmuir circulation, were strong, while its intensity was also affected by surface heat flux. We also find that wind forcing play an important role in Langmuir turbulence when wind and wave are misaligned. Numerical experiments support these observed features. These results indicate that Langmuir turbulence mixes ocean surface strongly when surface waves are intense, but associated mixing properties are highly dependent on wind and wave directions.

Free Research Field

海洋物理学