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Resolving multi-scale mixing processes and their impacts using a twin tow-yo microstructure profiling system

Research Project

Project/Area Number 19H01965
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Review Section Basic Section 17020:Atmospheric and hydrospheric sciences-related
Research InstitutionTokyo University of Marine Science and Technology

Principal Investigator

NAGAI TAKEYOSHI  東京海洋大学, 学術研究院, 准教授 (90452044)

Co-Investigator(Kenkyū-buntansha) 長谷川 大介  国立研究開発法人水産研究・教育機構, 水産資源研究所(塩釜), 主任研究員 (10624728)
井上 龍一郎  国立研究開発法人海洋研究開発機構, 地球環境部門(海洋観測研究センター), 主任研究員 (80624022)
山崎 秀勝  東京海洋大学, 学術研究院, 教授 (80260537)
Project Period (FY) 2019-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000)
Fiscal Year 2022: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2021: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2020: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2019: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Keywords黒潮 / サブメソスケール / 高解像度観測 / 自由落下曳航 / 乱流 / 栄養塩 / トカラ海峡 / 海山 / 対称不安定 / 乱流混合 / 近慣性内部波 / 日向灘 / 内部波最小周波数 / 渦、フロント / 自由落下曳航式観測 / 栄養塩フラックス / 二台準同時 / 乱流観測 / 生物化学センサー / 断面観測 / 高解像度
Outline of Research at the Start

海洋では様々なスケールの流動が海水の攪拌や混合に影響を及ぼす事が明らかとなった。また、近年の研究によって、サブメソスケールの流動が、マイクロスケールの乱流現象と密接に関わっている事が明らかとなりつつある。しかし、このマルチスケールで発生する混合現象が及ぼす影響は、フロント構造と乱流を数値モデルや観測で同時に解像することが困難であるため、未だ不明瞭である。そこで本研究では、サブメソスケールのフロント流動・乱流微細構造や栄養塩などの生物化学的要素を同時に観測する手法を確立し、サブメソスケール現象によって発生した乱流混合の影響を明らかとすることを目的とした、現場観測を主体とした研究を実施する。

Outline of Final Research Achievements

A free-fall tow-yo turbulence profiler, Underway-VMP (UVMP), and a free-fall tow-yo biochemical profiler that can measure nitrate concentrations necessary for phytoplankton growth in the field using ultraviolet light have been developed and observation methods established. Observations using these profilers showed that turbulence 100-1000 times larger than typical thermocline values were seen over 100 km, and the results were published in Comm Earth & Environment in 2021. These observations were used again in the Tokara Strait in September 2020 and showed that the Kuroshio Current flowing south of Kyushu is a very large turbulence and nutrient hotspot.

Academic Significance and Societal Importance of the Research Achievements

本研究で確立された2台同時自由落下曳航観測手法は、海洋の乱流混合と硝酸塩濃度などの生物化学的要素を、サブメソスケール(0.1-10km)で解像することを可能とした。これによって、サブメソスケールの不安定現象が実際に乱流や栄養塩輸送をどの程度引き起こし得るのかを観測から直接的に明らかにすることができる。これは極めて新規性の高いデータの取得を可能とする。これらを用いたトカラ海峡を流れる黒潮での現場観測結果は、九州南方が黒潮やその下流である本州南岸を肥沃化する重要な海域であることを示す。これは何故貧栄養な黒潮に高い魚類生産が維持されているのかを解明する大きな手がかりを与え社会的な意義が極めて大きい。

Report

(5 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Annual Research Report
  • 2020 Annual Research Report
  • 2019 Annual Research Report
  • Research Products

    (44 results)

All 2023 2022 2021 2020 2019 Other

All Journal Article (17 results) (of which Int'l Joint Research: 10 results,  Peer Reviewed: 17 results,  Open Access: 11 results) Presentation (18 results) (of which Int'l Joint Research: 18 results,  Invited: 1 results) Book (2 results) Remarks (7 results)

  • [Journal Article] Salt‐fingering under the thermal‐wind and lateral shears in the Kuroshio fronts2023

    • Author(s)
      Kimura Satoshi、Inoue Ryuichiro、Itoh Sachihiko、Nagai Takeyoshi
    • Journal Title

      Journal of Geophysical Research: Oceans

      Volume: NA Issue: 6

    • DOI

      10.1029/2022jc019435

    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] The Kuroshio Nutrient Stream: Where Diapycnal Mixing Matters2022

    • Author(s)
      Nagai Takeyoshi、Duran Gomez Gloria Silvana
    • Journal Title

      The Handbook of Environmental Chemistry

      Volume: NA Pages: 183-253

    • DOI

      10.1007/698_2021_833

    • ISBN
      9783662658376, 9783662658390
    • Related Report
      2022 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Decadal vision in oceanography 2021: Mid-latitude ocean2021

    • Author(s)
      橋濱史典・纐纈慎也・近藤能子・佐々木克徳・杉本周作・高橋一生・長井健容・西岡純・林田博士・平井淳也
    • Journal Title

      Oceanography in Japan

      Volume: 30 Issue: 5 Pages: 127-154

    • DOI

      10.5928/kaiyou.30.5_127

    • NAID

      130008131961

    • ISSN
      0916-8362, 2186-3105
    • Year and Date
      2021-11-15
    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] The Kuroshio flowing over seamounts and associated submesoscale flows drive 100-km-wide 100-1000-fold enhancement of turbulence2021

    • Author(s)
      Takeyoshi Nagai, Daisuke Hasegawa, Eisuke Tsutsumi, Hirohiko Nakamura, Ayako Nishina, Tomoharu Senjyu, Takahiro Endoh, Takeshi Matsuno, Ruyichiro Inoue, and Amit Tandon
    • Journal Title

      Communications earth & environment

      Volume: ー Issue: 1 Pages: 1-11

    • DOI

      10.1038/s43247-021-00230-7

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Elevated turbulent and double-diffusive nutrient flux in the Kuroshio over the Izu Ridge and in the Kuroshio Extension2021

    • Author(s)
      T. Nagai, G. M. Rosales Quintana, G. S. Duran Gomez, F. Hashihama, K. Komatsu
    • Journal Title

      J. Oceanogr

      Volume: 77 Issue: 1 Pages: 55-74

    • DOI

      10.1007/s10872-020-00582-2

    • NAID

      40022471976

    • Related Report
      2021 Annual Research Report 2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] How a small reef in the Kuroshio cultivates the ocean2021

    • Author(s)
      Hasegawa D.、Matsuno T.、Tsutsumi E.、Senjyu T.、Endoh T.、Tanaka T.、Yoshie N.、Nakamura H.、Nishina A.、Kobari T.、Nagai T.、Guo X.
    • Journal Title

      Geophysical Research Letters

      Volume: 印刷中 Issue: 7 Pages: 1-11

    • DOI

      10.1029/2020gl092063

    • NAID

      120007027029

    • Related Report
      2021 Annual Research Report 2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Phytoplankton Increase Along the Kuroshio Due to the Large Meander2021

    • Author(s)
      Lizarbe Barreto, Daniel Andres and Chevarria Saravia, Ricardo and Nagai, Takeyoshi and Hirata, Takafumi
    • Journal Title

      Frontiers in Marine Science

      Volume: 8 Pages: 1010-1010

    • DOI

      10.3389/fmars.2021.677632

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Mesoscale Warm-Core Eddies Drive Interannual Modulations of Swordfish Catch in the Kuroshio Extension System2020

    • Author(s)
      Duran Gomez Gloria Silvana、Nagai Takeyoshi、Yokawa Kotaro
    • Journal Title

      Frontiers in Marine Science

      Volume: 7

    • DOI

      10.3389/fmars.2020.00680

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Phytoplankton growth and consumption by microzooplankton stimulated by turbulent nitrate flux suggest rapid trophic transfer in the oligotrophic Kuroshio2020

    • Author(s)
      Kobari Toru、Honma Taiga、Hasegawa Daisuke、Yoshie Naoki、Tsutsumi Eisuke、Matsuno Takeshi、Nagai Takeyoshi、Kanayama Takeru、Karu Fukutaro、Suzuki Koji、Tanaka Takahiro、Guo Xinyu、Kume Gen、Nishina Ayako、Nakamura Hirohiko
    • Journal Title

      Biogeosciences

      Volume: 17 Issue: 9 Pages: 2441-2452

    • DOI

      10.5194/bg-17-2441-2020

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Multiscale routes to supply nutrients through the Kuroshio nutrient stream2019

    • Author(s)
      Nagai, T., S. Clayton & Y. Uchiyama
    • Journal Title

      Kuroshio Current: Physical, Biogeochemical and Ecosystem Dynamics

      Volume: 243 Pages: 105-125

    • DOI

      10.1002/9781119428428.ch6

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] The Research Advancements and Historical Episodes brought by the Kuroshio Flowing across Generations2019

    • Author(s)
      Nagai, T., Otsuka, K., & H. Nakano
    • Journal Title

      Kuroshio Current: Physical, Biogeochemical and Ecosystem Dynamics

      Volume: 243 Pages: 13-22

    • DOI

      10.1002/9781119428428.ch2

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Mixing Associated with Submesoscale Processes2019

    • Author(s)
      Tandon Amit、Nagai Takeyoshi
    • Journal Title

      Encyclopedia of Ocean Sciences, Third Edition

      Volume: na-na Pages: 567-577

    • DOI

      10.1016/b978-0-12-409548-9.10952-2

    • ISBN
      9780128130827
    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] How the Kuroshio Current delivers nutrients to sunlit layers on the continental shelves with aid of near-inertial waves and turbulence2019

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran, Diego Andre Otero, Yasutaka Mori, Naoki Yoshie, Kazuki Ohgi, Daisuke Hasegawa, Ayako Nishina, Toru Kobari
    • Journal Title

      Geophysical Research Letters

      Volume: na Issue: 12 Pages: 6726-6735

    • DOI

      10.1029/2019gl082680

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] On the Future of Argo: A Global, Full-Depth, Multi-Disciplinary Array2019

    • Author(s)
      Roemmich D., Alford M.H., Claustre H., Johnson K., King B., Moum J., Oke P., Owens B., Pouliquen S., Purkey S., Scanderbeg M., Suga T., Wijffels S., Zilberman N., Bakker D., Baringer M., Fujiki T., Hibiya T., Hosoda S., Yasuda I. ほか57名
    • Journal Title

      Frontiers in Marine Science

      Volume: 6 Pages: 1-28

    • DOI

      10.3389/fmars.2019.00439

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Global Perspectives on Observing Ocean Boundary Current Systems2019

    • Author(s)
      Todd Robert E.、Chavez Francisco P.、Clayton Sophie、Cravatte Sophie、Goes Marlos、Graco Michelle、Lin Xiaopei、Sprintall Janet、Zilberman Nathalie V.、Archer Matthew、Ito Shin-ichi、Nagai Takeyoshi、ほか
    • Journal Title

      Frontiers in Marine Science

      Volume: 6 Pages: 1-38

    • DOI

      10.3389/fmars.2019.00423

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] センサによる硝酸塩鉛直乱流拡散フラックスの計測2019

    • Author(s)
      長谷川大介, 田中雄大, 松野健, 千手智晴, 堤英輔, 中村啓彦, 仁科文子, 小針統, 吉江直樹, 郭新宇, 長井健容, 奥西武, 安田一郎
    • Journal Title

      沿岸海洋研究

      Volume: 57 Pages: 59-64

    • NAID

      130007841838

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] 黒潮上流から続流の鉛直混合過程とその影響に関する考察2019

    • Author(s)
      長井健容
    • Journal Title

      沿岸海洋研究

      Volume: 57 Pages: 43-58

    • NAID

      130007841839

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Presentation] Effects of the Kuroshio nutrient stream intrusion into the north of Yaku Island and Osumi Strait south of Kyushu2022

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran Gomez
    • Organizer
      PICES Annual Meeting 2022 Korea Busan
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Assessment of turbulent mixing impact on productivity and higher trophic levels along the Kuroshio in the Tokara Strait2022

    • Author(s)
      Gloria Silvana Duran Gomez, Takeyoshi Nagai, Toru Kobari, Hirohiko Nakamura, Ingibjorg Bjorgvinsdottir
    • Organizer
      JpGU Annual Meeting 2022
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Subsurface phytoplankton increase caused by submesoscale instability and associated turbulent mixing in the Kuroshio flowing over seamounts2022

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran Gomez, Hiroaki Saito, Hiroshi Ogawa, Toru Kobari, Naoki Yoshie
    • Organizer
      JpGU Annual Meeting 2022
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Turbulent Mixing and Nutrient Supply associated with the Kuroshio Induced Submesoscale Anticyclonic Vorticity over Seamounts and Continental slopes in the south of Kyushu Japan2022

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran Gomez, Hiroaki Saito, Hiroshi Ogawa, Toru Kobari, Naoki Yoshie
    • Organizer
      AGU Fall Meeting 2022 Chicago
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Assessment of nutrient supply processes associated with anticyclonic vorticity and cyclonic eddy on biological production in the Tokara Strait along the Kuroshio2022

    • Author(s)
      Gloria S. Duran Gomez, Takeyoshi Nagai, Toru Kobari, Hirohiko Nakamura, Kristinn Þröstur Sigurdarson, Ingibjorg Bjorgvinsdottir
    • Organizer
      AGU Fall Meeting 2022 Chicago
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] The Kuroshio nutrient stream: Where diapycnal mixing matters2021

    • Author(s)
      Nagai, T., G.S. Duran Gomez
    • Organizer
      JpGU Annual Meeting 2021
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Elevated nutrient supply caused by the Kuroshio induced vertical mixing near the continental slope associated with submesoscale flows and near-inertial waves2021

    • Author(s)
      Duran Gomez, G.S., Nagai, T.
    • Organizer
      JpGU Annual Meeting 2021
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Revealing unseen subsurface physical biogeochemical reactions caused by submesoscale instability and associated turbulent mixing in the Kuroshio flowing over seamounts2021

    • Author(s)
      Nagai, T., G.S. Duran Gomez, H. Saito, H. Ogawa, T. Kobari, N. Yoshie
    • Organizer
      Ocean Sciences Meeting 2022 Virtual
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Tracking turbulent mixing and its influence on productivity along the Kuroshio in the Tokara Strait2021

    • Author(s)
      Duran Gomez, G.S., Nagai, T., T. Kobari, H. Nakamura, I. Bjorgvinsdottir
    • Organizer
      Ocean Sciences Meeting 2022 Virtual
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] The long lasting strong turbulence along the Kuroshio flowing over seamounts in the Tokara Strait2020

    • Author(s)
      長井 健容、堤 英輔、長谷川 大介、中村 啓彦、仁科 文子、松野 健、千手 智晴
    • Organizer
      JpGU Annual Meeting 2020
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Elevated nutrient supply caused by the Kuroshio approaching to the continental shelf associated with submesoscale flows and near-inertial waves2020

    • Author(s)
      Gloria Silvana Duran Gomez, Takeyoshi Nagai
    • Organizer
      AGU Fall Meeting
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Blending source of turbulence, upwelled nutrients and primary producers in the Kuroshio flowing through the Tokara Strait2020

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran Gomez, Toru Kobari, Naoki Yoshie
    • Organizer
      AGU Fall Meeting
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nutrient Supply Caused by Submesoscale and Microscale Mixing Processes in the Upstream Kuroshio2020

    • Author(s)
      Takeyoshi Nagai, Daisuke Hasegawa, Eisuke Tsutsumi, Hirohiko Nakamura, Tomoharu Senjyu, Takahiro Endoh, Takeshi Matsuno, Ryuichiro Inoue, Amit Tandon, Naoki Yoshie, Kazuki Ohgi, Ayako Nishina, Toru Kobari, Gloria Silvana Duran Gomez and Diego Andre Otero
    • Organizer
      Ocean Science Meeting 2020, San Diego
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] How the Kuroshio enriches the southern coast of Japan and its downstream regions2019

    • Author(s)
      Takeyoshi Nagai, Gloria Silvana Duran Gomez, Diego Andre Otero Huaman, Yoshie Naoki, Kazuki Ohgi, Daisuke Hasegawa, Sophie Clayton, Yusuke Uchiyama
    • Organizer
      PICES Annual Meeting 2019, Victoria, Canada
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Physical and biogeochemical processes from winter to spring in the south of the Kuroshio Extension2019

    • Author(s)
      鋤柄 千穂、井上 龍一郎、長井 健容、Andrea Fassbender、Yuichiro Takeshita、Stuart Bishop、岡 英太郎
    • Organizer
      JpGU Annual Meeting 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Multiscale transport, stirring, and mixing processes to supply nutrients through the Kuroshio nutrient stream2019

    • Author(s)
      長井 健容、Clayton Sophie、内山 雄介
    • Organizer
      JpGU Annual Meeting 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 日向灘沖の陸棚斜面近傍を流れる黒潮において、水平30km、鉛直200m規模で観測された著しく強い乱流混合2019

    • Author(s)
      長井 健容、Duran Silvana、Otero Diego、森 泰貴、吉江 直樹、大城 一輝、長谷川 大介、仁科 文子、小針 統
    • Organizer
      JpGU Annual Meeting 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Turbulent mixing and near-inertial internal waves induced by the Kuroshio over seamounts in the Tokara Strait2019

    • Author(s)
      長井 健容、長谷川 大介、堤 英輔、中村 啓彦、仁科 文子、千手 智晴、遠藤 貴洋、松野 健、井上 龍一郎、Amit Tandon
    • Organizer
      JpGU Annual Meeting 2019
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Book] The Kuroshio nutrient stream: Where diapycnal mixing matters, In Chemical Oceanography in frontal zones2022

    • Author(s)
      T. Nagai, G. S. Duran Gomez
    • Publisher
      Springer Nature
    • Related Report
      2021 Annual Research Report
  • [Book] Kuroshio Current: Physical, Biogeochemical and Ecosystem Dynamics2019

    • Author(s)
      Takeyoshi Nagai, Hiroaki Saito, Koji Suzuki, Motomitsu Takahashi
    • Total Pages
      326
    • Publisher
      AGU-Wiley
    • ISBN
      1119428343
    • Related Report
      2019 Annual Research Report
  • [Remarks] Takeyoshi Nagai webpage

    • Related Report
      2022 Annual Research Report
  • [Remarks] Turbulence in the Kuroshio

    • URL

      https://doi.org/10.6084/m9.figshare.19777453.v1

    • Related Report
      2021 Annual Research Report
  • [Remarks] Tokara Mixing

    • URL

      https://doi.org/10.6084/m9.figshare.19618158.v5

    • Related Report
      2021 Annual Research Report
  • [Remarks] DráGóN Blessings

    • URL

      https://doi.org/10.6084/m9.figshare.19606999.v3

    • Related Report
      2021 Annual Research Report
  • [Remarks] Phytoplankton Increase Due to the Large Meander

    • URL

      https://doi.org/10.6084/m9.figshare.15164421.v1

    • Related Report
      2021 Annual Research Report
  • [Remarks] 長井健容のウェブサイト

    • Related Report
      2020 Annual Research Report
  • [Remarks] 長井健容のウェブサイト

    • Related Report
      2019 Annual Research Report

URL: 

Published: 2019-04-18   Modified: 2024-01-30  

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