数値シミュレーションによる北太平洋栄養物質循環の三次元構造と長期変動の解明

• Project Area: Ocean Mixing Processes: Impact on Biogeochemistry, Climate and Ecosystem
• Project/Area Number: 18H04909
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Research Institution: Hokkaido University
• Principal Investigator: 三寺 史夫 北海道大学, 低温科学研究所, 教授 (20360943)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥11,050,000 (Direct Cost: ¥8,500,000、Indirect Cost: ¥2,550,000); Fiscal Year 2019: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2018: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000)
• Keywords: オホーツク海 / 潮汐混合 / 栄養物質循環 / 親潮 / 鉄 / 数値モデル実験 / 栄養塩データセット / 海洋物質循環 / 海洋循環モデル / 北太平洋

Outline of Annual Research Achievements

本研究の目的は、オホーツク海・ベーリング海・親潮など北太平洋西部亜寒帯海域の「豊かな海の恵み」を生み出す仕組みを明らかにすることである。北西北太平洋における高い生物生産性を解明するためには、海洋の中深層に蓄えられている栄養塩や鉄分がどこで表層に湧き上がり、どの経路を通って西部亜寒帯海域に至るのか、という北太平洋全体の三次元的な物質循環の理解が不可欠である。その解明を目指し、栄養物質循環の数値モデリングを実施した。また、縁辺海を含めた新たな栄養塩データにより長期変動とモデル再現性の評価を行った。
本課題では、次の３つのサブテーマを設けて研究を進めた。第１に、オホーツク海・ベーリング海を含む西部北太平洋亜寒帯循環の中解像度の物質循環モデル（水平格子0.5°）による数値実験である。これにより、親潮海域における栄養物質の季節変動及び経年変動メカニズムを解明した。第２に、オホーツク海を特に高解像（水平格子の最小値3㎞程度）にした北太平洋物質循環モデルの開発である。起潮力によって潮汐を駆動し、乱流クロージャーを通して潮汐混合を物質循環モデルに組み込むという、新たなモデリングに挑戦し、親潮海域の高い生物生産性の再現に成功した。潮汐有り・無し実験、および経年変動実験を実行した。第３に、北太平洋表層の新たな栄養塩データセットを作成した。最新のデータを取り入れることで、オホーツク海、ベーリング海など縁辺海を含む領域に拡張するとともに、データ期間も2017年まで延伸した。
以上の研究により、（１）親潮およびその東方の移行領域で特に生物生産が大きいこと、そして、（２）オホーツク海北西陸棚域から移流される鉄とベーリング海の冬季混合により亜表層から湧昇したリン酸塩が、千島列島における潮汐混合の作用を受けながら親潮海域で出会うことで高い生物生産が引き起こされること、が明らかとなった。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] スクリプス海洋研究所(米国)
• [Journal Article] Mechanism of ice-band pattern formation caused by resonant interaction between sea ice and internal waves in a continuously stratified ocean (2021)
  • Author(s): Saiki Ryu、Mitsudera Humio、Fujisaki-Manome Ayumi、Kimura Noriaki、Ukita Jinro、Toyota Takenobu、Nakamura Tomohiro
  • Journal Title: Progress in Oceanography Volume: 190 Pages: 102474-102474
  • DOI: 10.1016/j.pocean.2020.102474
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Spatial Distribution and Seasonality of Halocline Structures in the Subarctic North Pacific (2020)
  • Author(s): Katsura, S., H. Ueno, H. Mitsudera, S. Kouketsu
  • Journal Title: Journal of Physical Oceanography Volume: 50 Issue: 1 Pages: 95-109
  • DOI: 10.1175/jpo-d-19-0133.1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [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] Nutrients and dissolved inorganic carbon variability in the North Pacific (2020)
  • Author(s): Yasunaka, S., H. Mitsudera, F. Whitney, S. Nakaoka
  • Journal Title: Journal of Oceanography Volume: 77 Issue: 1 Pages: 3-16
  • DOI: 10.1007/s10872-020-00561-7
  • NAID: 40022471956
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Long-term trend and interannual to decadal variability in the Sea of Okhotsk. In: Chen CT., Guo X. (eds) Changing Asia-Pacific Marginal Seas (2020)
  • Author(s): Nakanowatari, T., and H. Mitsudera
  • Journal Title: Atmosphere, Earth, Ocean & Space Volume: - Pages: 19-56
  • DOI: 10.1007/978-981-15-4886-4_3
  • ISBN: 9789811548857, 9789811548864
  • Peer Reviewed / Open Access
• [Journal Article] Dynamics of a Quasi-Stationary Jet along the Subarctic Front in the North Pacific Ocean (the Western Isoguchi Jet): An Ideal Two-layer Model (2018)
  • Author(s): Miyama, T., H. Mitsudera, H. Nishigaki, and R. Furue
  • Journal Title: Journal of Physical Oceanography Volume: 48 Issue: 4 Pages: 807-830
  • DOI: 10.1175/jpo-d-17-0086.1
  • Peer Reviewed / Open Access
• [Presentation] Impacts of riverine discharges on the overturning circulation and material circulation in the Sea of Okhotsk and the North Pacific Ocean (2020)
  • Author(s): H. Mitsudera, T. Miyama, H. Nishikawa
  • Organizer: JpGU-AGU Joint Meeting 2020, Online
  • Int'l Joint Research / Invited
• [Presentation] カムチャツカ半島からの淡水供給が制御するオホーツク海と北太平洋の子午面循環 (2020)
  • Author(s): 三寺 史夫、美山 透、白岩 孝行、史 穆清、小松 謙介、立花 義裕、中田 聡史、西川はつみ
  • Organizer: JpGU-AGU Joint Meeting 2020, Online
  • Int'l Joint Research
• [Presentation] Surface water pathways and land-ocean freshwater linkages associated with the meridional overturn that ventilates the intermediate layer of the Sea of Okhotsk and North Pacific Ocean (2020)
  • Author(s): Mitsudera, H., T. Miyama, T. Shiraiwa, Y. Tachibana, K. Komatsu, H. Nishikawa
  • Organizer: The 35th International Symposium on the Okhotsk Sea & Polar Oceans
  • Int'l Joint Research
• [Presentation] Reproduction of Iron-rich Intermediate Water in the Subarctic North Pacific by High-resolution Biogeochemical Model (2020)
  • Author(s): Nishikawa H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakamura, K. Uchimoto, H. Hasumi
  • Organizer: OSM 2020
  • Int'l Joint Research
• [Presentation] Reveal of Dynamics of Barotropic Exchange between the Sea of Okhotsk and North Pacific through Tidal forcing in High-Resolution Ocean General Circulation Model: the Modification of the Western Boundary Current Pathway by Tidal Rectification (2020)
  • Author(s): H.W. Shu, H. Mitsudera, K. Yamazaki, T. Kawasaki, T. Nakamura, H. Sasaki, H. Nishikawa
  • Organizer: Ocean Science Meeting 2020
  • Int'l Joint Research
• [Presentation] Dynamics of water exchange processes at a deep submarine canyon off the western coast of the Sakhaline which causes the origin of the cold water belt along the Soya Warm Current (2019)
  • Author(s): Mitsudera H., H. Iida
  • Organizer: JpGU 2019
  • Int'l Joint Research / Invited
• [Presentation] 北太平洋移行領域の海面水温フロント形成 (2019)
  • Author(s): 西川はつみ，三寺史夫，奥西武，伊藤進一，和川拓，長谷川大介，美山透，金子仁
  • Organizer: 大槌シンポジウム
• [Presentation] Reproduction of iron-rich intermediate water in the Sea of Okhotsk by high resolution biogeochemical model (2019)
  • Author(s): Nishikawa H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakamura, K. Uchimoto, H. Hasumi
  • Organizer: IWMO 2019
  • Int'l Joint Research
• [Presentation] Formation mechanism for the North Pacific Transition domain SST and SSS fronts (2019)
  • Author(s): Nishikawa H., H. Mitsudera, T. Okunishi, S. Ito, T. Wagawa, D. Hasegawa, T. Miyama and H. Kaneko
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] Reproduction of iron-rich intermediate water in the Sea of Okhotsk by high resolution biogeochemical model (2019)
  • Author(s): Nishikawa H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakamura, K. Uchimoto, H. Hasumi
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] High-resolution modeling of iron and phosphate transport in the subarctic North Pacific (2019)
  • Author(s): Nishikawa H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakamura, K. Uchimoto, H. Hasumi
  • Organizer: SOLAS 2019
  • Int'l Joint Research
• [Presentation] Improvement and Dynamics of Water Exchange between the Sea of Okhotsk and the Pacific through tidal effects in OGCM (2019)
  • Author(s): H.W. Chou, H. Mitsudera, K. Yamazaki, H. Nishikawa
  • Organizer: 4th International Joint Workshop on Computationally Intensive Modeling of the Climate System and 9th OFES International Workshop
  • Int'l Joint Research
• [Presentation] Impact of Tidal Vertical Mixing to Barotropic Water Exchange between the Sea of Okhotsk and Pacific through Diffusive Adjustment with Turbulent Closure Scheme: Can Vertical Diffusivity Vale represent the Tidal Impact in OGCM? (2019)
  • Author(s): H.W. Chou, H. Mitsudera, H. Nishikawa K. Yamazaki
  • Organizer: JpGU, 2019
  • Int'l Joint Research
• [Presentation] Numerical simulation of typhoon storm surge in the LUOYUAN bay (2019)
  • Author(s): Yuan Nan, Xinping Chen, Xueen Chen, Jinrui Chen,Humio Mitsudera
  • Organizer: Geoscience Union Meeting 2019
  • Int'l Joint Research
• [Presentation] Numerical simulation of typhoon storm surge in the LUOYUAN bay (2019)
  • Author(s): Yuan Nan, Xinping Chen, Xueen Chen, Jinrui Chen,Humio Mitsudera
  • Organizer: The 11th International Workshop on Modeling the Ocean
  • Int'l Joint Research
• [Presentation] On global distribution and interannual variability of wintertime halocline (2019)
  • Author(s): Oda, M., H. Ueno, H. Mitsudera
  • Organizer: The 34th International Symposium on the Okhotsk Sea & Polar Oceans 2019
  • Int'l Joint Research
• [Presentation] Dynamical frontogenesis in the transitional regions between the subtropical and the subpolar gyres (2018)
  • Author(s): Mitsudera, H.
  • Organizer: JpGU 2018
  • Int'l Joint Research / Invited
• [Presentation] Large-scale nutrient variation in the North Pacific Transitional Area (2018)
  • Author(s): Yasunaka, S.
  • Organizer: PICES-PTA Symposium
  • Int'l Joint Research / Invited
• [Presentation] High resolution biogeochemical modelling in the North Pacific (2018)
  • Author(s): Nishikawa H., H. Mitsudera, H. Yoshinari, T. Nakanowatari, T. Nakamura, K. Uchimoto, H. Hasumi
  • Organizer: JpGU 2018
  • Int'l Joint Research
• [Presentation] Subtropical seawater transport pathway of the North Pacific Transition Domain observed with drifting buoys (2018)
  • Author(s): Nishikawa H., H. Mitsudera, T. Okunishi, S. Ito, T. Wagawa, D. Hasegawa, T. Miyama, H. Kaneko.
  • Organizer: JpGU 2018
  • Int'l Joint Research / Invited
• [Presentation] Bottom flow formation accompanied by the baroclinic instability in the downstream region of the Soya Warm Current during summer (2018)
  • Author(s): Karaki, T., H. Mitsudera, S. Kida
  • Organizer: JpGU 2018
  • Int'l Joint Research
• [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
  • Int'l Joint Research
• [Presentation] Potential impacts of the freshwater flux from the Kamchatka Peninsula on the dense shelf water formation in the Sea of Okhotsk (2018)
  • Author(s): Mitsudera, H.
  • Organizer: JpGU 2018
  • Int'l Joint Research
• [Presentation] Dynamics of Brazil/Malvinas confluence and its bifurcation in the Subtropical Front and the Subantarctic Front (2018)
  • Author(s): Mitsudera, H.
  • Organizer: 10th International Workshop on Modeling the Ocean
  • Int'l Joint Research
• [Presentation] Formation and interannual variations of baroclinic quasi-stationary jets in the transitional domain between the subtropical and subarctic gyres in the western North Pacific (2018)
  • Author(s): Mitsudera, H., T. Miyama, H. Nishigaki, T. Nakanowatari, H. Nishikawa, T. Nakamura, T. Wagawa, Ryo Furue, Yosuke Fujii, and Shin-Ichi Ito
  • Organizer: PICES-2018 Annual Meeting
  • Int'l Joint Research
• [Presentation] ブラジル・マルビナス合流域の亜熱帯前線・亜寒帯前線への分岐の力学 (2018)
  • Author(s): 三寺史夫，東弓弦，Chou H.-W., 青木茂
  • Organizer: 2018年度日本海洋学会秋季大会
• [Presentation] Dynamics of barotropic water exchange between the Okhotsk and Pacific by tidal effects (2018)
  • Author(s): Chou, H. W., 三寺史夫, 西川はつみ
  • Organizer: 2018年度日本海洋学会秋季大会
• [Presentation] 漂流ブイ観測から視る北太平洋移行領域の亜熱帯水輸送経路 (2018)
  • Author(s): 西川はつみ，三寺史夫，奥西武，伊藤進一，和川拓，長谷川大介，美山透，金子仁
  • Organizer: 2018年度日本海洋学会秋季大会
• [Presentation] 北太平洋移行領域の形成メカニズムと変動 (2018)
  • Author(s): 西川はつみ，三寺史夫，奥西武，伊藤進一，和川拓，長谷川大介，美山透，金子仁
  • Organizer: 大槌シンポジウム
• [Presentation] 北太平洋表層栄養塩の季節・経年変動 (2018)
  • Author(s): 安中さやか・野尻幸宏・小埜恒夫・中岡慎一郎・Frank Whitney
  • Organizer: 北大低温研共同利用研究集会「西部北太平洋亜寒帯域における物質循環および海洋生態系とのリンケージ」
• [Remarks] 環オホーツク観測研究センター
  • URL: https://sites.google.com/view/pan-okhotsk/home