Unified understanding of ocean mixing processes and impacts

• Project Area: Ocean Mixing Processes: Impact on Biogeochemistry, Climate and Ecosystem
• Project/Area Number: 20H05598
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Complex systems
• Research Institution: The University of Tokyo
• Principal Investigator: 安田 一郎 東京大学, 大気海洋研究所, 教授 (80270792)
• Project Period (FY): 2020-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2020: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: 海洋混合学 / 鉛直混合 / 海洋物質循環 / 海洋生態系 / 気候変動 / 潮汐 / 乱流 / 海洋循環 / 海洋鉛直混合

Outline of Research at the Start

本研究領域では「鉛直混合の実態の解明を通じて、西部北太平洋において、どこでどのような鉛直混合が働き、栄養塩を含む中深層水が湧昇し、親潮や黒潮に影響を与え、気候を変え、生物生産の維持と長周期変動につながるのか、混合過程を軸として統合的に解明し、新しい学術領域「海洋混合学」を構築する」ことを目的に研究を行ってきた。本研究では、1) 研究成果を集約し発信する。2) 成果と今後の課題を集約した総括論文を含む特集号を国際誌に出版するとともに最終報告を取りまとめる。3) 得られた観測データ及び数値シミュレーションデータを集約し、論文化後公開する。4) 次世代に引き継がれる新しい問いを、とりまとめて残す。

Outline of Annual Research Achievements

新学術領域「新海洋混合学(2015-2019年度)」では、「鉛直混合の実態の解明を通じて、西部北太平洋において、どこでどのような鉛直混合が働き、栄養塩を含む中深層水が湧昇し、親潮や黒潮に影響を与え、気候を変え、生物生産の維持と長周期変動につながるのか、混合過程を軸として統合的に解明し、新しい学術領域「海洋混合学」を構築する」ことを目的に研究を行ってきた。これまで観測が難しく極めて希少だった海洋鉛直混合の現場観測データを容易に得られる手法を開発し、多くの観測データが取得され、海洋混合についての理解が大きく進んだ。また、時空間で数桁変動する海洋混合の影響を取り込んだ海洋モデルが開発され、海洋深層循環や栄養塩や炭酸系物質をはじめとする物質循環、生態系へ影響の理解が大きく進んだ。これら研究成果を取りまとめて発信し、次世代の研究に活かすために、研究成果と今後の課題を取りまとめた本領域独自の最終成果報告書を刊行し関係者に配布するとともに、科研費事後報告書及び研究概要を公開した。新学術領域の取りまとめ会議を2020年４月末に行なった他、海洋混合学日本地球惑星科学連合(JpGU)-米国地球惑星科学連合(AGU)の連合大会（２０２０年５月）の海洋混合研究のセッションにおいて、広く研究成果を発信した。国際誌「Journal of Oceanography(スプリンガー出版)」に本領域の特集号を企画し、20本の原著・レビュー論文を出版した。さらに、国際誌「Progress in Oceanography」誌において、ロシア船航海を元にした研究成果の特集号を企画し、13本の論文を出版した。また、これら論文となった現場観測およびモデルのデータをアーカイブし公開した。

Research Progress Status

令和2年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和2年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] ワシントン大学/スクリプス海洋研究所/オレゴン州立大学(米国)
• [Int'l Joint Research] 海洋研究所(韓国)
• [Int'l Joint Research] 極東水文気象研究所(ロシア連邦)
• [Int'l Joint Research] 青島海洋大学(中国)
• [Int'l Joint Research] BBBP(インドネシア)
• [Journal Article] Estimate of turbulent energy dissipation rate using free-fall and CTD-attached fast-response thermistors in weak ocean turbulence (2021)
  • Author(s): Yasuda Ichiro、Fujio Shinzou、Yanagimoto Daigo、Lee KeungJong、Sasaki Yusuke、Zhai Shuo、Tanaka Mamoru、Itoh Sachihiko、Tanaka Takahiro、Hasegawa Daisuke、Goto Yasutaka、Sasano Daisuke
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 1 Pages: 17-28
  • DOI: 10.1007/s10872-020-00574-2
  • NAID: 40022471961
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Vertical turbulent nitrate flux from direct measurements in the western subarctic and subtropical gyres of the North Pacific (2021)
  • Author(s): Kaneko Hitoshi、Yasuda Ichiro、Itoh Sachihiko、Ito Shin-ichi
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 1 Pages: 29-44
  • DOI: 10.1007/s10872-020-00576-0
  • NAID: 40022471968
  • Peer Reviewed / Open Access
• [Journal Article] Enhanced vertical turbulent nitrate flux in the intermediate layer of the Kuroshio in the Tokara Strait (2021)
  • Author(s): Tanaka T.、Hasegawa D.、Yasuda I.、Yanagimoto D.、Fujio S.、Nakamura H.、Inoue R.、Nishioka J.
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 1 Pages: 45-53
  • DOI: 10.1007/s10872-020-00581-3
  • Peer Reviewed / Open Access
• [Journal Article] Estimation of Basin-scale turbulence distribution in the North Pacific Ocean using CTD-attached thermistor measurements (2021)
  • Author(s): Goto Yasutaka、Yasuda Ichiro、Nagasawa Maki、Kouketsu Shinya、Nakano Toshiya
  • Journal Title: Scientific Reports Volume: 11 Issue: 1 Pages: 969-969
  • DOI: 10.1038/s41598-020-80029-2
  • Peer Reviewed / Open Access
• [Journal Article] Observations of anticyclonic eddies in the western subarctic North Pacific (2021)
  • Author(s): Dobashi Ryo、Ueno Hiromichi、Okada Yuki、Tanaka Takahiro、Nishioka Jun、Hirawake Toru、Ooki Atushi、Itoh Sachihiko、Hasegawa Daisuke、Sasai Yoshikazu、Sasaki Hideharu、Yasuda Ichiro
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 2 Pages: 229-242
  • DOI: 10.1007/s10872-020-00586-y
  • Peer Reviewed
• [Journal Article] Widespread distribution of allochthonous fluorescent dissolved organic matter in the intermediate water of the North Pacific (2021)
  • Author(s): Yamashita Youhei、Tosaka Tetsu、Bamba Rise、Kamezaki Ryuichi、Goto Shuji、Nishioka Jun、Yasuda Ichiro、Hirawake Toru、Oida Joji、Obata Hajime、Ogawa Hiroshi
  • Journal Title: Progress in Oceanography Volume: 191 Pages: 102510-102510
  • DOI: 10.1016/j.pocean.2020.102510
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Vertical eddy diffusivity in the subsurface pycnocline across the Pacific (2021)
  • Author(s): Itoh S.、Kaneko H.、Kouketsu S.、Okunishi T.、Tsutsumi E.、Ogawa H.、Yasuda I.
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 2 Pages: 185-197
  • DOI: 10.1007/s10872-020-00589-9
  • Peer Reviewed / Open Access
• [Journal Article] Synchronized interdecadal variations behind regime shifts in the Pacific Decadal Oscillation (2021)
  • Author(s): Hamamoto Masaki、Yasuda Ichiro
  • Journal Title: Journal of Oceanography Volume: 印刷中 Issue: 3 Pages: 383-392
  • DOI: 10.1007/s10872-021-00592-8
  • Peer Reviewed
• [Journal Article] The potential role of thermohaline?shear instability in turbulence production in the Bering Sea and the subarctic North Pacific (2021)
  • Author(s): Tanaka Mamoru、Yoshida Jiro、Lee Keunjong、Goto Yasutaka、Tanaka Takahiro、Ueno Hiromichi、Onishi Hiroji、Yasuda Ichiro
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 3 Pages: 431-446
  • DOI: 10.1007/s10872-021-00602-9
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Nanomolar phosphate supply and its recycling drive net community production in the subtropical North Pacific (2021)
  • Author(s): Hashihama Fuminori、Yasuda Ichiro、Kumabe Aki、Sato Mitsuhide、Sasaoka Hiroshi、Iida Yosuke、Shiozaki Takuhei、Saito Hiroaki、Kanda Jota、Furuya Ken、Boyd Philip W.、Ishii Masao
  • Journal Title: Nature Communications Volume: 12 Issue: 1 Pages: 3462-3462
  • DOI: 10.1038/s41467-021-23837-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Iron and nutrient dynamics along the East Kamchatka current, western Bering sea basin and Gulf of Anadyr (2021)
  • Author(s): Nishioka J, Hirawake T, Nomura D, Yamashita Y, Ono K, Murayama A, Shcherbinin A, Volkov Y N, Mitsudera H, Ebuch N, Wakatsuchi M, Yasuda I
  • Journal Title: Progress in Oceanography Volume: - Pages: 102662-102662
  • DOI: 10.1016/j.pocean.2021.102662
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Distribution of leptocephali and wintertime hydrographic structure in the Kuroshio Extension and northern subtropical gyre (2020)
  • Author(s): Miller Michael J.、Itoh Sachihiko、Watanabe Shun、Shinoda Akira、Saruwatari Toshiro、Tsukamoto Katsumi、Yasuda Ichiro
  • Journal Title: Deep Sea Research Part I: Oceanographic Research Papers Volume: 159 Pages: 103240-103240
  • DOI: 10.1016/j.dsr.2020.103240
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Subpolar marginal seas fuel the North Pacific through the intermediate water at the termination of the global ocean circulation (2020)
  • Author(s): Nishioka Jun、Obata Hajime、Ogawa Hiroshi、Ono Kazuya、Yamashita Youhei、Lee Keunjong、Takeda Shigenobu、Yasuda Ichiro
  • Journal Title: Proceedings of the National Academy of Sciences Volume: 117 Issue: 23 Pages: 12665-12673
  • DOI: 10.1073/pnas.2000658117
  • NAID: 120006937024
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Microstructure and Mooring Observations of Enhanced Mixing in the Kerama Gap (2020)
  • Author(s): Inoue Ryuichiro、Tanaka Takahiro、Nakamura Hirohiko、Yanagimoto Daigo、Fujio Shinzou、Yasuda Ichiro
  • Journal Title: Journal of Geophysical Research: Oceans Volume: 125 Issue: 8
  • DOI: 10.1029/2019jc015553
  • Peer Reviewed
• [Journal Article] Cold Water Upwelling Near the Anadyr Strait: Observations and Simulations (2020)
  • Author(s): Kawaguchi Yusuke、Nishioka Jun、Nishino Shigeto、Fujio Shinzou、Lee Keunjong、Fujiwara Amane、Yanagimoto Daigo、Mitsudera Humio、Yasuda Ichiro
  • Journal Title: Journal of Geophysical Research: Oceans Volume: 125 Issue: 9 Pages: 1-18
  • DOI: 10.1029/2020jc016238
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Vertical fluxes of nutrients enhanced by strong turbulence and phytoplankton bloom around the ocean ridge in the Luzon Strait (2020)
  • Author(s): Tsutsumi Eisuke、Matsuno Takeshi、Itoh Sachihiko、Zhang Jing、Senjyu Tomoharu、Sakai Akie、Lee Keunjong、Yanagimoto Daigo、Yasuda Ichiro、Ogawa Hiroshi、Villanoy Cesar
  • Journal Title: Scientific Reports Volume: 10 Issue: 1 Pages: 1-11
  • DOI: 10.1038/s41598-020-74938-5
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Ocean mixing processes (OMIX): impact on biogeochemistry, climate and ecosystem (2020)
  • Author(s): Yasuda, I., S. Masuda, J. Nishioka, X. Guo, N Harada, S. Ito, T. Hibiya, H. Hasumi
  • Journal Title: J. Oceanogr. Volume: 77 Issue: 1 Pages: 1-1
  • DOI: 10.1007/s10872-020-00578-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Estimating the population mean for a vertical profile of energy dissipation rate (2020)
  • Author(s): Sugiura Nozomi、Kouketsu Shinya、Masuda Shuhei、Osafune Satoshi、Yasuda Ichiro
  • Journal Title: Scientific Reports Volume: 10 Issue: 1
  • DOI: 10.1038/s41598-020-77414-2
  • Peer Reviewed / Open Access
• [Presentation] 千島から新海洋混合学Turbulence Observation: Kuril Straits to Ocean Mixing (OMIX) Project (2022)
  • Author(s): 安田一郎
  • Organizer: 2022/3/18 乱流研究会、東京大学・小柴ホール
  • Invited
• [Presentation] 北太平洋亜熱帯域の純群集生産を駆動するナノモルレベルのリン供給と 迅速な再生 (2021)
  • Author(s): 橋濱史典・安田一郎・隈部あき・佐藤光秀・笹岡洋志・飯田洋介・塩崎拓平・齊藤宏明・神田穣太・古谷研・Philip W. Boyd・石井雅男
  • Organizer: 2021日本海洋学会秋季大会
• [Presentation] Observation of energy transfer from traveling typhoons to turbulent mixing in the ocean (2021)
  • Author(s): Aiqi Zhang, Ichiro Yasuda, Daigo Yanagimoto, Shinzo Fujio, Yusuke Sasaki
  • Organizer: JpGU Meeting 2021 A-OS11 “Ocean Mixing Frontiers”
  • Int'l Joint Research
• [Presentation] Overview of OMIX project “Ocean mixing processes: impact on biogeochemistry, climate and ecosystems (2020)
  • Author(s): Ichiro Yasuda
  • Organizer: JpGU-AGU 2020: "U-18: Open Colloquium: Recent advances in atmospheric and hydrospheric sciences" 14h July, 2020
  • Int'l Joint Research / Invited
• [Presentation] Development of efficient and autonomous microstructure measurement system using fast-response thermistors attached to CTD, glider and deep-profiling float, to elucidate vertical distribution (2020)
  • Author(s): Ichiro Yasuda, Keunjong Lee, Yasutaka Goto, Maki Nagasawa, Shuo Zhai, Yusuke Sasaki, Daigo Yanagimoto, Shinzou Fujio, Mamoru Tanaka, Shinya Kouketsu, Toshiya Nakano, Daisuke Sasano, Takahiro Tanaka
  • Organizer: JpGU-AGU 2020: A-OS24 "Exploring new frontiers of oceanic mixing research in the next decade”
  • Int'l Joint Research
• [Presentation] Eddy-resolved ocean characteristics of the Miroc coupled model incorporating effects of tidal mixing of the 18.6-yr modulation (2020)
  • Author(s): Tomonori Matsuura, Hiromasa Tatebe, and Ichiro Yasuda
  • Organizer: JpGU-AGU Joint session A-OS24 "Exploring new frontiers of oceanic mixing research in the next decade”
  • Int'l Joint Research
• [Presentation] 高速水温計を用いた乱流計測手法: 測定下限と CTD 取り付け計測の改善 (2020)
  • Author(s): 安田一郎・藤尾伸三・柳本大吾・K.-J.Lee・佐々木雄亮・S. Zhai・田中衛・伊藤幸彦・田中雄大・長谷川大介・後藤恭敬・笹野大輔
  • Organizer: ブルーアースシンポジウム、2020/12/18
• [Presentation] アナディル海峡における冷水湧昇:ロシア船・「みらい」による現場観測 と数値実験 (2020)
  • Author(s): 川口悠介・西岡純・西野茂人・藤尾伸三・ 藤原周・柳本大吾・李根淙・三寺史夫・安田一郎
  • Organizer: 20F-02-2 2020/11/27 日本海洋学会秋季大会
• [Presentation] 南大洋域におけるDiffusive型対流が及ぼす鉛直熱輸送の推定 (2020)
  • Author(s): 佐々木雄亮・安田一郎・勝又 勝郎・纐纈慎也・内田裕
  • Organizer: 20F-17-7 2020/11/2８ 日本海洋学会秋季大会、口頭発表
• [Presentation] 回転及び鉛直シア存在下でのdiffusive型二重拡散対流の直接数値計算 (2020)
  • Author(s): 松村義正・新野宏・安田一郎
  • Organizer: 20F-17-8 2020/11/2８ 日本海洋学会秋季大会、口頭発表
• [Presentation] 千島ブッソル海峡において観測された流速変動特性 (2020)
  • Author(s): 柳本大吾・安田一郎・藤尾伸三・田中雄大・後藤恭敬・西岡純
  • Organizer: 20F-02-P1 2020/11/2８ 日本海洋学会秋季大会 ポスター
• [Presentation] 天皇海山列北端を通過する深層流 (2020)
  • Author(s): 藤尾伸三・柳本大吾・川口悠介・安田一郎・李根淙・西岡純
  • Organizer: 20F-02-P2 2020/11/2８ 日本海洋学会秋季大会 ポスター
• [Remarks] 海洋混合学の創設「物質循環・気候・生態系の維持と長周期変動の解明」
  • URL: http://omix.aori.u-tokyo.ac.jp
• [Remarks] OMIX国際活動報告
  • URL: http://omix.aori.u-tokyo.ac.jp/international-activity/
• [Remarks] OMIX研究成果報告
  • URL: http://omix.aori.u-tokyo.ac.jp/achievements/
• [Remarks] OMIXニュースレター
  • URL: http://omix.aori.u-tokyo.ac.jp/news_letter/
• [Funded Workshop] Ocean Turbulence Symposium dedicated for Prof. Hibiya (2021)
• [Funded Workshop] JpGU-AGU annual meeting session A-OS24 Exploring new frontiers of oceanic mixing research in the next decade (2020)