東部インド洋湧昇域における物理・化学・生物学的特性の統合的解明

2020 Fiscal Year Annual Research Report

• Project/Area Number: 17H01663
• Research Institution: The University of Tokyo
• Principal Investigator: 升本 順夫 東京大学, 大学院理学系研究科(理学部), 教授 (60222436)
• Co-Investigator(Kenkyū-buntansha): 齊藤 宏明 東京大学, 大気海洋研究所, 教授 (30371793) ; 植木 巌 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), グループリーダー (60371712) ; 日比谷 紀之 東京大学, 大学院理学系研究科(理学部), 教授 (80192714)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 東部インド洋 / 分野統合的研究 / 白鳳丸観測航海 / 湧昇域 / インドネシア多島海 / 乱流混合

Outline of Annual Research Achievements

東部インド洋およびインドネシア多島海で2018/2019年度に実施した観測により得られたデータの詳細な検討を行うとともに、衛星データや数値モデルを用いて表層循環場やトレーサー場の変動機構や乱流混合過程に関する解析を進めた。
2018年後半にインドネシアとオーストラリアに挟まれた海域において観測された表層水温の負偏差が長期に渡り維持されたのは、海面での熱フラックスによる冷却効果が寄与しており、大気のマッデン-ジュリアン振動の影響が大きいことがわかった。また、2018年に行った東経88度測線上の赤道域には表層のクロロフィル濃度が通常よりも高い海域があり、Wyrtkiジェットに伴う水平移流による栄養塩供給が植物プランクトンの増殖を促したことが示唆された。
衛星クロロフィルデータの解析から、ジャワ-スマトラ島沿岸の湧昇がダイポールモード現象に数ヶ月先行して発生していることを明らかにした。さらに、2019年の正のダイポールモード現象では、温度躍層変動が海上風に起因した複数のメカニズムで生じていることを示すと共に、沿岸付近に地衡流では説明できない東向流が存在していたことが明らかとなった。
乱流直接観測の結果から、強い乱流ホットスポットは特定の狭い海峡内に存在し、海嶺や海山上での内部潮汐波の砕波に伴って局所的に発生していること、そこから離れると鉛直乱流拡散率は典型的な外洋の値へと急速に低下してしまうことが明らかになった。さらに、高分解能数値シミュレーションから、これらの狭い海峡内では、内部潮汐波の砕波による鉛直混合だけでなく、サブメソスケール（10 km程度）の渦によって強化された水平混合も加わることで、非常に短い距離（10km）の間で著しい水塊変質が起こっていることが示唆された。

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] Badan Riset dan Inovasi Nasional（BRIN）(インドネシア)
  • Country Name: INDONESIA
  • Counterpart Institution: Badan Riset dan Inovasi Nasional（BRIN）
• [Journal Article] Phytoplankton dynamics as a response to physical events in the oligotrophic Eastern Indian Ocean (2022)
  • Author(s): Jiang, S., F. Hashihama, Y. Masumoto, H. Liu, H. Ogawa, and H. Saito
  • Journal Title: Progress in Oceanography Volume: 203 Pages: 102784
  • DOI: 10.1016/j.pocean.2022.102784
  • Peer Reviewed / Open Access
• [Journal Article] A new parameterization of turbulent mixing enhanced over rough seafloor topography (2022)
  • Author(s): Hibiya T.
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: e2021GL096067
  • DOI: 10.1029/2021GL096067
  • Peer Reviewed / Open Access
• [Journal Article] Can coastal upwelling trigger a climate mode? A study on intraseasonal-scale coastal upwelling off Java and the Indian Ocean Dipole (2022)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, I. Ueki, and K. Ando
  • Journal Title: Geophys. Res. Lett. Volume: 49 Pages: e2022GL098733
  • DOI: 10.1029/2022GL098733
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Interpreting Reynolds Stress from Perspective of Eddy Geometry (2021)
  • Author(s): Aoki, K., and Y. Masumoto
  • Journal Title: Dynamics of Atmospheres and Oceans Volume: 94 Pages: 101223
  • DOI: 10.1016/j.dynatmoce.2021.101223
  • Peer Reviewed / Open Access
• [Journal Article] Physical and biogeochemical processes associated with upwelling in the Indian Ocean (2021)
  • Author(s): Vinayachandran, P.N., Y. Masumoto, M. Roberts, J. Hugget, I. Halo, A. Chatterjee, P. Amol, GVM Gupta, A. Singh, A. Mukherjee, S. Prakash, L. Beckley, E. Raes, and R. Hood
  • Journal Title: Biogeosciences Volume: 18 Pages: 5967-6029
  • DOI: 10.5194/bg-18-5967-2021
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Direct estimates of turbulent mixing in the Indonesian archipelago and its role in the transformation of the Indonesian throughflow waters (2021)
  • Author(s): Nagai, T., T. Hibiya, and F. Syamsudin
  • Journal Title: Geophysical Research Letters Volume: 48 Pages: e2020GL091731
  • DOI: 10.1029/2020GL091731
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Indonesian Throughflow and its Impact on Biogeochemistry in the Indonesian Seas (2020)
  • Author(s): Taufiqurrahman, E., A. J. Wahyudi, and Y. Masumoto
  • Journal Title: ASEAN Journal on Science & Technology for Development Volume: 37 Pages: 29-35
  • DOI: 10.29037/ajstd.596
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] What did determine the warming trend in the Indonesian sea?, (2020)
  • Author(s): Iskandar, I., W. Mardiansyah, D.O. Lestari, and Y. Masumoto
  • Journal Title: Prog. Earth Planet Sci. Volume: 7 Pages: -
  • DOI: 10.1186/s40645-020-00334-2
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A roadmap to IndOOS-2: Better observations of the rapidly-warming Indian Ocean (2020)
  • Author(s): Beal, L. M., J. Vialard, M.K. Roxy, J. Li, M. Andres, H. Annamalai, M. Feng, W. Han, R. Hood, T. Lee, M. Lengaigne, R. Lumpkin, Y. Masumoto, et al.
  • Journal Title: Bull. Amer. Meteor. Soc. Volume: 101 Pages: E1891-E1913
  • DOI: 10.1175/BAMS-D-19-0209.1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A global eddying hindcast ocean simulation with OFES2 (2020)
  • Author(s): Sasaki, H., S. Kida, R. Furue, H. Aiki, N. Komori, Y. Masumoto, T. Miyama, M. Nonaka, Y. Sasai, and B. Taguchi
  • Journal Title: Geosci. Model Dev. Volume: 13 Pages: 3319-3336
  • DOI: 10.5194/gmd-13-3319-2020
  • Peer Reviewed / Open Access
• [Journal Article] Spatial structure of turbulent mixing inferred from historical CTD datasets in the Indonesian seas (2020)
  • Author(s): Purwandana, A., Y. Cuypers, P. Bouruet-Aubertot, T. Nagai, T. Hibiya, A. S. Atmadipoera
  • Journal Title: Progress in Oceanography Volume: 184 Pages: 102312
  • DOI: 10.1016/j.pocean.2020.102312
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A parameterization of local and remote tidal mixing (2020)
  • Author(s): de Lavergne, C., C. Vic, G. Madec, F. Roquet, A. F. Waterhouse, C. B. Whalen, Y. Cuypers, P. Bouruet-Aubertot, B. Ferron, and T. Hibiya
  • Journal Title: Journal of Advances in Modeling Earth Systems Volume: 12 Pages: e2020MS002065
  • DOI: 10.1029/2020MS002065
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Historical CTD dataset and associated processed dissipation rate using an improved Thorpe method in the Indonesian seas (2020)
  • Author(s): Purwandana, A., Y. Cuypers, P. Bouruet-Aubertot, T. Nagai, T. Hibiya, A. S. Atmadipoera
  • Journal Title: Data in Brief Volume: 30 Pages: 105519
  • DOI: 10.1016/j.dib.2020.105519
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Combined effects of tidal mixing in narrow straits and the Ekman transport on the sea surface temperature cooling in the southern Indonesian Seas (2020)
  • Author(s): Nagai, T., and T. Hibiya
  • Journal Title: Journal of Geophysical Research: Oceans, Volume: 125 Pages: e2020JC016314
  • DOI: 10.1029/2020JC016314
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Modified View of Energy Budget Diagram and its Application to the Kuroshio extension region (2020)
  • Author(s): Matsuta, T., and Y. Masumoto
  • Journal Title: J. Phys. Oceanogr. Volume: 51 Pages: 1163-1175
  • DOI: 10.1175/JPO-D-20-0124.1
  • Peer Reviewed / Open Access
• [Journal Article] Coastal upwelling events, salinity stratification, and barrier layer observed along the southwestern coast of Sumatra (2020)
  • Author(s): Horii, T., I. Ueki, and K. Ando
  • Journal Title: J. Geophys. Res. Volume: 125 Pages: e2020JC016287
  • DOI: 10.1029/2020JC016287
  • Peer Reviewed / Open Access
• [Presentation] ジャワ島沖沿岸湧昇の季節変動－再考 (2022)
  • Author(s): 升本順夫
  • Organizer: 2022年度冬季 海洋力学勉強会
• [Presentation] Indo-Pacific interbasin exchange of equatorial wave energy through the Indonesian archipelago in a reduced gravity model (2022)
  • Author(s): Terada, Y. and Y. Masumoto
  • Organizer: Ocean Sciences Meeting 2022
  • Int'l Joint Research
• [Presentation] Quantitative Evaluation of Tropical Ocean Waves from the Indian Ocean to the Pacific Ocean through the Indonesian Seas (2022)
  • Author(s): Terada, Y., and Y. Masumoto
  • Organizer: JpGU2022
  • Int'l Joint Research
• [Presentation] Coastal upwelling events along the southern coasts of Sumatra and Java observed by Argo floats (2022)
  • Author(s): Horii, T., I. Ueki, and K. Ando
  • Organizer: International Indian Ocean Science Conference (IIOSC) 2022
  • Int'l Joint Research
• [Presentation] Surface Chlorophyll-a variations associated with coastal upwelling along the southern coast of Java and the Indian Ocean Dipole (2022)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, and I. Ueki
  • Organizer: Ocean Sciences Meeting 2022
  • Int'l Joint Research
• [Presentation] インド~太平洋域における海洋観測の過去から現在、そして未来 (2022)
  • Author(s): 安藤健太郎、植木巌
  • Organizer: 令和4年度海洋理工学会春季大会
• [Presentation] 衛星観測のクロロフィルa濃度データを用いたジャワ島南の沿岸湧昇の指標 (2022)
  • Author(s): 堀井孝憲, 植木巌, Eko Siswanto, Iskhaq Iskandar
  • Organizer: 日本海洋学会 2022年度秋季大会
• [Presentation] Use of ocean color data for climate prediction: A study on coastal upwelling off Java and the Indian Ocean Dipole (2022)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, I. Ueki, and K. Ando
  • Organizer: 10th Asian Workshop on Ocean Color (AWOC) & 19th Japan/Korea Workshop on Ocean Color (JKWOC)
  • Int'l Joint Research
• [Presentation] Can coastal upwelling trigger a climate mode? A study on intraseasonal-scale coastal upwelling off Java and the Indian Ocean Dipole (2022)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, I. Ueki, and K. Ando
  • Organizer: American Geophysical Union (AGU) Fall Meeting 2022
  • Int'l Joint Research
• [Presentation] Revisiting turbulent mixing hotspots over rough seafloor topography (2022)
  • Author(s): Hibiya, T., and Y. Hirano
  • Organizer: Japan Geoscience Union Meeting
  • Int'l Joint Research
• [Presentation] Near-field Mixing のパラメタリゼーションに関する再考察 (2022)
  • Author(s): 日比谷紀之, 平野雄介
  • Organizer: 日本海洋学会 2022年度秋季大会
• [Presentation] Distribution and movement of microplastics in the Indian Ocean (2021)
  • Author(s): Masumoto, Y.
  • Organizer: JpGU2021
  • Int'l Joint Research
• [Presentation] インド洋-太平洋域の持続的発展のための海洋情報の取得と活用に関する検討 (2021)
  • Author(s): 升本順夫、安藤健太郎、江渕直人、齊藤宏明、八木信行
  • Organizer: 日本海洋政策学会第13回年次大会
• [Presentation] Eddy-mean flow interactions and vertical energy redistribution associated with the standing meander in the Antarctic Circumpolar Current (2021)
  • Author(s): Matsuta, T., and Y. Masumoto
  • Organizer: JpGU2021
  • Int'l Joint Research
• [Presentation] 南極周極流にローレンツ・ダイアグラムを適用する際の問題点 (2021)
  • Author(s): 松田拓朗・升本順夫
  • Organizer: 日本海洋学会2021年度秋季大会
• [Presentation] インドネシア多島海を通じた太平洋-インド洋間の波動エネルギー伝播経路 -太平洋から入射する場合- (2021)
  • Author(s): 寺田雄亮・升本順夫
  • Organizer: 日本海洋学会2021年度秋季大会
• [Presentation] Indo-Pacific interbasin exchange of equatorial wave energy through the Indonesian archipelago in a reduced gravity model (2021)
  • Author(s): Terada, Y. and Y. Masumoto
  • Organizer: Approaches for Hydrospheric-Atmospheric Environmental Studies in Asia-Oceania 2021
  • Int'l Joint Research
• [Presentation] Coastal ecosystem study in the Indian Ocean and adjacent seas under international collaboration (2021)
  • Author(s): Saito, H., Y. Masumoto, and Z. Arifin
  • Organizer: JpGU2021
  • Int'l Joint Research
• [Presentation] Intraseasonal surface Chlorophyll-a variations associated with coastal upwelling south of Java, and its relation to the Indian Ocean Dipole (2021)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, and I. Ueki
  • Organizer: American Geophysical Union (AGU) Fall Meeting 2021
  • Int'l Joint Research
• [Presentation] Surface Chlorophyll-a variations associated with coastal upwelling south of Java, and its relation to the Indian Ocean Dipole (2021)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, I. Ueki
  • Organizer: 2021年度名古屋大学宇宙地球環境研究所研究集会:インド洋/太平洋域における海洋循環/環境応用に 関する研究集会
  • Int'l Joint Research
• [Presentation] ジャワ島沖の沿岸湧昇の発生時期とその後のインド洋ダイポール現象の発達 (2021)
  • Author(s): 堀井 孝憲, Eko Siswanto, Iskhaq Iskandar, 植木 巌
  • Organizer: 日本海洋学会2021年度秋季大会
• [Presentation] Intraseasonal variation of surface Chlorophyll-a associated with coastal upwelling along the southern coast of Java (2021)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, and I. Ueki
  • Organizer: Japan Geoscience Union (JpGU) Meeting 2021
  • Int'l Joint Research
• [Presentation] Intraseasonal variation of surface Chlorophyll-a associated with coastal upwelling along the southern coast of Java (2021)
  • Author(s): Horii, T., E. Siswanto, I. Iskandar, and I. Ueki
  • Organizer: AOGS2021 Virtual 18th Annual Meeting
  • Int'l Joint Research
• [Presentation] Direct estimates of turbulent mixing in the Indonesian Archipelago and its role in the transformation of the ITF waters (2021)
  • Author(s): Nagai, T., and T. Hibiya
  • Organizer: Japan Geoscience Union Meeting 2021
  • Int'l Joint Research
• [Presentation] Upwelling off Sumatraand Java and its role in climate systems, (2020)
  • Author(s): Masumoto, Y.
  • Organizer: International Conference on the Ocean and Earth Sciences
  • Int'l Joint Research / Invited
• [Presentation] 2018年11-12月の東部インド洋における物理・生物地球化学・生態系に関連する諸量の分布特性 (2020)
  • Author(s): 升本順夫・齊藤宏明・小川浩史・小畑元
  • Organizer: 海と地球のシンポジウム2020
• [Presentation] The Mode Water formation in the South Indian Ocean (2020)
  • Author(s): Matsuta, T., and Y. Masumoto
  • Organizer: JpGU2020
  • Int'l Joint Research
• [Presentation] 南インド洋におけるモード水の変性メカニズム (2020)
  • Author(s): 松田拓朗・升本順夫
  • Organizer: 日本海洋学会2020年度秋季大会
• [Presentation] The combined effect of tidal mixing in narrow straits and the Ekman transport on the variability of SST in the southern Indonesian Seas (2020)
  • Author(s): Nagai, T., and T. Hibiya
  • Organizer: Ocean Sciences Meeting 2020
  • Int'l Joint Research / Invited
• [Presentation] Direct estimates of turbulent mixing in the Indonesian Seas and its impact on the water-mass transformation (2020)
  • Author(s): Nagai, T., and T. Hibiya
  • Organizer: Ocean Sciences Meeting 2020
  • Int'l Joint Research
• [Presentation] A new parameterization of tidal mixing enhanced over rough seafloor topography (2020)
  • Author(s): Hibiya, T.
  • Organizer: Ocean Sciences Meeting 2020
  • Int'l Joint Research
• [Presentation] A new parameterization of tidal mixing enhanced over rough seafloor topography (2020)
  • Author(s): Hibiya, T.
  • Organizer: Japan Geoscience Union-American Geophysical Union Joint Meeting 2020
  • Int'l Joint Research
• [Presentation] Temporary phytoplankton biomass increases in oligotrophic subtropical and tropical oceans (2020)
  • Author(s): 江 思宇 ・ 橋濱 史典 ・ 齊藤 宏明
  • Organizer: 日本海洋学会2020年度秋季大会
• [Presentation] Observation in the Java-Sumatra upwelling region during positive IOD in 2019 (2020)
  • Author(s): Ueki, I.
  • Organizer: JpGU-AGU Joint Meeting 2020 Virtual
• [Presentation] A role of eastward-propagating intraseasonal oscillation in controlling coastal upwelling southwest of Sumatra (2020)
  • Author(s): Horii, T., and I. Ueki
  • Organizer: JpGU-AGU Joint Meeting 2020 Virtual
  • Int'l Joint Research
• [Presentation] Coastal upwelling events, salinity stratification and barrier layer along the southern縲?coasts of Sumatra and Java (2020)
  • Author(s): Horii, T., I. Ueki, and K. Ando
  • Organizer: American Geophysical Union (AGU) Fall Meeting 2020
  • Invited
• [Funded Workshop] Workshop: Approaches for Hydrospheric-Atmospheric Environmental Studies in Asia-Oceania (2020)