Water mass structure and primary productivity in the sub-Arctic seas revealed from dissolved organic matter and optical properties

• Project/Area Number: 19H04250
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: National Institute of Polar Research (2020-2022); Hokkaido University (2019)
• Principal Investigator: Hirawake Toru 国立極地研究所, 先端研究推進系, 教授 (70311165)
• Co-Investigator(Kenkyū-buntansha): 山下 洋平 北海道大学, 地球環境科学研究院, 准教授 (50432224)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000); Fiscal Year 2022: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2021: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2020: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2019: ¥10,400,000 (Direct Cost: ¥8,000,000、Indirect Cost: ¥2,400,000)
• Keywords: CDOM / FDOM / 水塊 / 光吸収 / 蛍光 / 基礎生産 / 水塊混合 / 有色溶存有機物 / 光吸収・蛍光 / 水塊指標 / 水塊分類 / 溶存有機物 / 三陸沖 / 混合

Outline of Research at the Start

親潮と黒潮はそれぞれ異なる特徴を持つ海水である（水塊）。三陸沖はこれらが複雑に混合することで豊かな生物生産力を生み出し、水産業にとっても重要な海域である。今後の海洋生物資源の動態を知る上で、水塊構造と生物資源の基盤となる基礎生産力を理解することが必要であるが、水塊の同一性と起源を、水温・塩分のみで判断することは困難である。そこで溶存有機物の吸光・蛍光特性を新たなトレーサーとして活用し、新しい水塊構造の解析方法を提案し、海洋循環・物質循環と生物生産力との関係を解明する。さらに、センサー観測や衛星リモートセンシングによる広範囲・多次元・連続観測研究へと発展させる。

Outline of Final Research Achievements

Light absorption and fluorescence of chromophoric dissolved organic matter (CDOM) were investigated in the waters off Sanriku coast, the shelf region of the Bering Sea, and adjacent seas where seawaters with various characteristic distribute nearby each other and mixing. Using these optical characteristics of CDOM, we classified seawaters with the same characteristics (water masses) and succeeded to discriminate the water masses three dimensionally from data of fluorescence sensors and ocean color satellite sensors. Our results also suggested that water masses affected by coastal sediments and contributing to phytoplankton production could be discriminated.

Academic Significance and Societal Importance of the Research Achievements

水塊の判別には水温と塩分が使われることが通例であるが、CDOMの情報を利用した本研究結果は、水温・塩分だけでは判別困難な沿岸堆積物の影響や、生物生産を促進させる水塊の生成過程の理解を大きく前進させるものである。今後、これらのプロセスを海洋生態系モデルに組みことで、我が国の持続的な海洋生物資源利用と管理および日本列島を含めた亜寒帯の生態学的研究と炭素循環研究の基礎情報として役立つと期待される。

Research Products

• [Journal Article] Intrusion of Coastal Oyashio Water to Funka Bay and Tsugaru Strait occasionally disturbed by Kuroshio-originating warm core ring (2023)
  • Author(s): Abe, H., Y. Yahiro, T. Hasegawa, T. Hirawake, H. Onishi, A. Ooki, T. Takatsu, K. Sasaki, M. Wakita, H. Kaneko, S. Watanabe, T. Tanaka, T. Okunishi, S. Ohno, S. Hashizume
  • Journal Title: Journal of Oceanography Volume: - Issue: 4 Pages: 349-366
  • DOI: 10.1007/s10872-022-00675-0
  • Peer Reviewed
• [Journal Article] The efficiency of the microbial carbon pump as seen from the relationship between apparent oxygen utilization and fluorescent dissolved organic matter (2023)
  • Author(s): Xiao, X., Y. Yamashita, M. Gonsior, and N. Jiao
  • Journal Title: Progress in Oceanography Volume: 210 Pages: 102929-102929
  • DOI: 10.1016/j.pocean.2022.102929
  • Peer Reviewed
• [Journal Article] Dissolved iron concentration and the solubility inferred by humic-like fluorescent dissolved organic matter in the intermediate water in the North Pacific including the marginal seas (2023)
  • Author(s): Yamashita, Y., and J. Nishioka
  • Journal Title: Journal of Geophysical Research-Biogeosciences Volume: - Issue: 3
  • DOI: 10.1029/2022jg007159
  • Peer Reviewed / Open Access
• [Journal Article] Performance of primary production algorithm using absorption coefficient of phytoplankton in the Pacific Arctic (2022)
  • Author(s): Futsuki Ryosuke、Hirawake Toru、Fujiwara Amane、Waga Hisatomo、Kikuchi Takashi、Nishino Shigeto、Isada Tomonori、Suzuki Koji、Watanabe Yutaka W.
  • Journal Title: Journal of Oceanography Volume: 78 Issue: 4 Pages: 311-335
  • DOI: 10.1007/s10872-022-00646-5
  • Peer Reviewed
• [Journal Article] Biogeochemical and physical linkages between the Arctic Ocean and Sub-Arctic Pacific through marginal seas (2022)
  • Author(s): Nishioka Jun、Yasuda Ichiro、Hirawake Toru、Nakamura Tomohiro、Kondo Yoshiko、Volkov Yuri N.
  • Journal Title: Progress in Oceanography Volume: 203 Pages: 102768-102768
  • DOI: 10.1016/j.pocean.2022.102768
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Water mass distribution in the northern Bering and southern Chukchi seasusing light absorption of chromophoric dissolved organic matter (2021)
  • Author(s): Hirawake T, Ooida J, Yamashita Y, Waga H, Abe H, Nishioka J, Nomura D, Ueno H, Ooki A
  • Journal Title: Progres in Oceanography Volume: - Pages: 102641-102641
  • DOI: 10.1016/j.pocean.2021.102641
  • Peer Reviewed / Open Access
• [Journal Article] Performance of JAXA’s SGLI standard ocean color products for oceanic to coastal waters: chlorophyll a concentration and light absorption coefficients of colored dissolved organic matter (2021)
  • Author(s): Matsuoka Atsushi、Campbell Janet W.、Hooker Stanford B.、Steinmetz Fran?ois、Ogata Kazunori、Hirata Takafumi、Higa Hiroto、Kuwahara Victor S.、Isada Tomonori、Suzuki Koji、Hirawake Toru、Ishizaka Joji、Murakami Hiroshi
  • Journal Title: Journal of Oceanography Volume: Special Section Issue: 4 Pages: 1-22
  • DOI: 10.1007/s10872-021-00617-2
  • Peer Reviewed / Int'l Joint Research
• [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] Stratification in the northern Bering Sea in early summer of 2017 and 2018 (2020)
  • Author(s): Ueno, H., M. Komatsu, Z. Ji, R. Dobashi, M. Muramatsu, H. Abe, K. Imai, A. Ooki, and T. Hirawake
  • Journal Title: Deep-Sea Research, Part II Volume: 181-182 Pages: 104820-104820
  • DOI: 10.1016/j.dsr2.2020.104820
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Impacts of unusually light sea-ice cover in winter 2017-2018 on the northern Bering Sea marine ecosystem ? An introduction (2020)
  • Author(s): Hirawake Toru、Hunt George L.
  • Journal Title: Deep Sea Research Part II: Topical Studies in Oceanography Volume: 181-182 Pages: 104908-104908
  • DOI: 10.1016/j.dsr2.2020.104908
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Characterization of the Water Masses in the Shelf Region of the Bering and Chukchi Seas With Fluorescent Organic Matter (2019)
  • Author(s): Yamashita Youhei、Yagi Yuki、Ueno Hiromichi、Ooki Atsushi、Hirawake Toru
  • Journal Title: Journal of Geophysical Research: Oceans Volume: 124 Issue: 11 Pages: 7545-7556
  • DOI: 10.1029/2019jc015476
  • Peer Reviewed / Open Access
• [Journal Article] Impacts of Mesoscale Eddies on Phytoplankton Size Structure (2019)
  • Author(s): Waga Hisatomo、Hirawake Toru、Ueno Hiromichi
  • Journal Title: Geophysical Research Letters Volume: 46 Issue: 22 Pages: 13191-13198
  • DOI: 10.1029/2019gl085150
  • Peer Reviewed / Open Access
• [Presentation] Detection of biologically productive water mass from ocean color satellite using chromophoric dissolved organic matter (CDOM) (2022)
  • Author(s): Oida, J., T. Hirawake, Y. Yamashita, H. Abe, J. Nishioka, H. Waga, D. Nomura, S. Kakehi
  • Organizer: ESSAS Annual Science Meeting
  • Int'l Joint Research
• [Presentation] 太平洋側北極域における光吸収ベース基礎生産量アルゴリズムの性能 (2022)
  • Author(s): 平譯 享, 夫津木亮介, 藤原 周, 和賀久朋, 菊地 隆, 西野茂人, 伊佐田智規, 鈴木光次, 渡辺豊
  • Organizer: 日本海洋学会秋季大会
• [Presentation] 有色溶存有機物 (CDOM)を用いた海色衛星による高生産水塊の検出 (2022)
  • Author(s): 大井田 穣示, 平譯 享, 山下 洋平, 阿部 泰人, 西岡 純, 和賀 久朋, 野村 大樹, 筧 茂穂
  • Organizer: 日本海洋学会秋季大会
• [Presentation] 中層水循環により縁辺海から北太平洋に輸送される溶存鉄の化学形態 (2022)
  • Author(s): 山下洋平, 西岡 純
  • Organizer: 日本海洋学会秋季大会
• [Presentation] The nutrient supply and mixing control the primary production seasonality in the subarctic Pacific (2022)
  • Author(s): Toru Hirawake, Takuro Kaneko, Jun Nishioka, Hajime Obata, Ichiro Yasuda
  • Organizer: Ocean Carbon From Space Workshop
  • Int'l Joint Research
• [Presentation] Geographical distributions of primary production phenology and nutrient/iron supply in the subarctic North Pacific Ocean (2020)
  • Author(s): Toru Hirawake, Jun Nishioka, Hajime Obata
  • Organizer: JpGU 2020
• [Presentation] 衛星海色リモートセンシングによる沿岸域の観測 (2020)
  • Author(s): 平譯享，山下洋平，鈴木光次，西岡純
  • Organizer: JpGU 2020
  • Invited
• [Presentation] 有色溶存有機物(CDOM)から見る西部北太平洋及び北部ベーリング海の水塊構造と栄養塩分布 (2020)
  • Author(s): 大井田穣示，平譯享，山下洋平，阿部泰人、西岡純、和賀久朋 、野村大樹
  • Organizer: JpGU 2020
• [Presentation] 北太平洋における中層水循環に伴う外来性溶存有機物の輸送 (2020)
  • Author(s): 山下洋平, 森雄太郎, 遠坂哲, 亀崎龍一, 後藤周史, 西岡純, 馬場梨世, 安田一郎, 藤尾伸三, 平譯享, 大井田穣示, 小畑元, 小川浩史
  • Organizer: JpGU 2020
• [Presentation] Improvement of absorption-based primary production model for SGLI/GCOM-C (2019)
  • Author(s): Toru Hirawake, Takuhei Shiozaki, Hisatomo Waga, Koji Suzuki
  • Organizer: JpGU 2019
• [Book] リモートセンシング事典 （「海洋における基礎生産の推定」を担当） (2023)
  • Author(s): 日本リモートセンシング学会（平譯 享、執筆分担）
  • Total Pages: 758
  • Publisher: 丸善出版
  • ISBN: 9784621307762