Observations of ocean fine structures with scales between submeso-scale and turbulence using the three-dimensional current and turbidity observation system

• Project/Area Number: 16K05549
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Hokkaido University
• Principal Investigator: Nakamura Tomohiro 北海道大学, 低温科学研究所, 講師 (60400008)
• Research Collaborator: OOKI Atsushi ; SHIMODA Chikara
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 海洋物理 / 海洋科学 / 自然現象観測 / 乱流混合 / 内部波 / 流体

Outline of Final Research Achievements

Three-dimensional fine structures with scales smaller than O (1 km) are closely related to mixing, which is a fundamental process in the oceans. However, such structures are not well understood due to the lack of observation methods. In this study, we have made successful observations of three-dimensional structures of transitional processes from a breaking of large-amplitude internal waves to turbulence, using the three-dimensional current and turbidity observation system we developed.

Academic Significance and Societal Importance of the Research Achievements

本研究は、最も基本的な海洋現象の一つでありながら、長い間手つかずであった３次元微細構造の実態解明に向けた取組みである。微細構造は海洋中に遍く存在し、海洋運動の空間スケールの範囲のうち１／３強を占める。この海洋物理に残る広大なブラックボックスの実態解明は、それ自体、海洋物理学への大きな貢献と言えよう。微細構造の実態解明は、海水混合の理解と正確な評価・パラメタ化を介し、海洋の循環・物質循環・生態系そして長期変動の理解と将来予測の向上へ繋がる。

Research Products

• [Journal Article] Low ocean-floor rises regulate subpolar sea surface temperature by forming baroclinic jets (2018)
  • Author(s): Mitsudera H.、Miyama T.、Nishigaki H.、Nakanowatari T.、Nishikawa H.、Nakamura T.、Wagawa T.、Furue R.、Fujii Y.、Ito S.
  • Journal Title: Nature Communications Volume: 9 Issue: 1 Pages: 1-11
  • DOI: 10.1038/s41467-018-03526-z
  • NAID: 120006470992
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific (2017)
  • Author(s): Nakanowatari Takuya、Nakamura Tomohiro、Uchimoto Keisuke、Nishioka Jun、Mitsudera Humio、Wakatsuchi Masaaki
  • Journal Title: Journal of Geophysical Research Volume: 122 Issue: 5 Pages: 4364-4391
  • DOI: 10.1002/2016jc012354
  • NAID: 120006559266
  • Peer Reviewed / Open Access
• [Journal Article] 環オホーツク圏の海洋シミュレーション (2017)
  • Author(s): 中村知裕，三寺史夫，内本圭亮, 中野渡拓也
  • Journal Title: 化学工学 Volume: 81 Pages: 246-249
• [Journal Article] Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific (2017)
  • Author(s): Nakanowatari, T., T. Nakamura, K. Uchimoto, J. Nishioka, H. Mitsudera, and M. Wakatsuchi
  • Journal Title: Journal of Geophysical Research Volume: -
  • NAID: 120006559266
  • Peer Reviewed / Open Access
• [Presentation] Distribution, variation and statistics of the index of mixing due to interaction of a vortex and internal waves in the North Pacific (2019)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: The 34th International Symposium on Okhotsk Sea and Polar Oceans 2019
  • Int'l Joint Research
• [Presentation] Far-reaching effects of sea ice extent in the Sea of Okhotsk on sea-surface turbulent heat flux and their possible influence (2019)
  • Author(s): Nakamura, T., Y. Takahashi, T. Nakanowatari
  • Organizer: The 34th International Symposium on Okhotsk Sea and Polar Oceans 2019
  • Int'l Joint Research
• [Presentation] オホーツク海海氷による広範囲の海面熱フラックス変動：ストームトラックと海洋混合層への影響の可能性 (2018)
  • Author(s): 高橋祐輔、中村知裕、中野渡拓也
  • Organizer: 気象学会2018年度秋季大会
• [Presentation] オホーツク海海氷による広域の海面熱フラックス変動 (2018)
  • Author(s): 高橋祐輔、中村知裕、中野渡拓也
  • Organizer: 2018年度日本海洋学会秋季大会
• [Presentation] Data analysis of mixing due to interaction of vortex and internal waves with OFES30 (2018)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: JpGU 2018
• [Presentation] Seasonal to interannual variations in surface PO4 concentration in Oyashio region: Role of wind-induced coastally trapped currents (2018)
  • Author(s): Nakanowatari, T., T. Nakamura, H. Mitsudera, J. Nishioka
  • Organizer: JpGU 2018
• [Presentation] High resolution biogeochemical modelling in the North Pacific (2018)
  • Author(s): Nishikawa, H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakakmura, K. Uchimoto, H. Hasumi
  • Organizer: JpGU 2018
• [Presentation] Impact of interannual variations of sea ice area in the Sea of Okhotsk on the atmosphere and ocean (2018)
  • Author(s): Takahashi, Y., T. Nakamura, T. Nakanowatari
  • Organizer: The 33rd International Symposium on Okhotsk Sea and Polar Oceans 2018
  • Int'l Joint Research
• [Presentation] Interaction of a vortex and internal gravity waves: classification by a non-dimensional parameter (2017)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: International Symposium ``Ocean Mixing Processes: Impact on Biogeochemistry, Climate and Ecosystem"
  • Place of Presentation: The University of Tokyo, Tokyo
  • Year and Date: 2017-03-16
• [Presentation] An estimate of internal gravity wave trapping by vortices in the North Pacific using OFES 1/30deg output (2017)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: Meeting on Perspectives in Computational Atmosphere and Ocean Science and 8th OFES International Workshop
  • Place of Presentation: Nagoya University, Nagoya
  • Year and Date: 2017-03-13
• [Presentation] Effects of sedimentary supply on iron circulation in the North Pacific based on a high-resolution model (2017)
  • Author(s): Nakamura, T., H. Mitsudera, H. Yoshinari, T. Nakanowatari, H. Nishikawa, and K. Uchimoto
  • Organizer: The 32nd International Symposium on Okhotsk Sea and Polar Oceans 2017
  • Place of Presentation: Mombetsu Municipal Museum, Mombetsu
  • Year and Date: 2017-02-19
• [Presentation] Classification of interaction between a vortex and internal waves, and estimates of interaction-induced mixing in the North Pacific Ocean (2017)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: The 32nd International Symposium on Okhotsk Sea and Polar Oceans 2017
  • Place of Presentation: Mombetsu Municipal Museum, Mombetsu
  • Year and Date: 2017-02-19
• [Presentation] Effects of sedimentary supply on iron distribution in the North Pacific: Sensitivity experiments with a high-resolution model (2017)
  • Author(s): Nakamura, T., H. Mitsudera, H. Yoshinari, T. Nakanowatari, H. Nishikawa, K. Uchimoto
  • Organizer: 2018 Ocean Sciences Meeting
  • Int'l Joint Research
• [Presentation] Mapping of vortex and internal waves interaction-induced mixing in the North Pacific from OFES30 output (2017)
  • Author(s): Ito, K. and T. Nakamura
  • Organizer: JpGU-AGU Joint Meeting 2017
  • Int'l Joint Research
• [Presentation] 北太平洋亜寒帯域における物質循環の高解像度シミュレーション (2017)
  • Author(s): 西川はつみ、三寺史夫、吉成浩志、中野渡拓也、中村知裕
  • Organizer: 2017年度日本海洋学会秋季大会
• [Presentation] OFES出力を用いた渦・内部波相互作用による混合の解析 (2017)
  • Author(s): 伊藤薫、中村知裕
  • Organizer: 2017年度日本海洋学会秋季大会要旨集
• [Presentation] 北太平洋西部亜寒帯域のリン酸塩の経年変動 (2016)
  • Author(s): 中野渡拓也, 中村知裕, 西岡純, 三寺史夫, 内本圭亮, 若土正曉
  • Organizer: 低温研共同利用研究集会「西部北太平洋の微量元素の3次元循環像構築にむけたワークショップ」
  • Place of Presentation: 北海道大学, 札幌
  • Year and Date: 2016-11-14
• [Book] オホーツク海の下層雲・霧と大気海洋相互作用. 低温環境の科学事典, 第10章, 第2節 (2016)
  • Author(s): 中村知裕
  • Total Pages: 411
  • Publisher: 朝倉書店