Sea-ice reduction in the Pacific Arctic during summer from the variability of sea-ice thickness during winter

2022 Fiscal Year Annual Research Report

• Project/Area Number: 19H01961
• Research Institution: Hokkaido University
• Principal Investigator: 深町 康 北海道大学, 北極域研究センター, 教授 (20250508)
• Co-Investigator(Kenkyū-buntansha): 大島 慶一郎 北海道大学, 低温科学研究所, 教授 (30185251) ; 二橋 創平 苫小牧工業高等専門学校, 創造工学科, 教授 (50396321) ; 伊東 素代 国立研究開発法人海洋研究開発機構, 地球環境部門(北極環境変動総合研究センター), 副主任研究員 (60373453)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 海氷 / 北極海 / 海氷厚 / 係留観測 / 衛星観測

Outline of Annual Research Achievements

コロナ禍により今まで現地へ赴けなかった北極チュクチ海観測拠点バロー及びアラスカ大学に2023年10月に訪問し、2019年～2021年の2年間のチュクチ海での係留系観測データを取得した。これにより、バロー沖では2009年より連続して12年間に及ぶ、海氷厚、海氷漂流、海洋流速、海水温、塩分のデータセットを取得することができた。北極チュクチ海では、このような高精度の海氷・海洋同時観測データを連続して12年間取得した例はなく、貴重なデータを得ることができた。今年度は、分担者大島により12年間のADCPの後方散乱強度データの導出と解析を行った。ADCP散乱強度からは、フラジルアイス、海底堆積物の巻き上がり、動物プランクトン活動を捉えることができる。動物プランクトンに関しては、ボーフォート高気圧の変動に対応するような特徴的な変動を抽出することができた。これらのデータと海氷厚・海氷漂流データを比較することで、海氷変動と物質循環・生物活動との関係解明につながると考える。分担者伊東によっては、「みらい」や外国の砕氷船による船舶観測データから、太平洋側北極海公海の比較的浅い海域に位置するチュクチ海台で低酸素化・酸性化が進んだ海水の広がりを初めて捉えることに成功した。この現象は、北極海の海氷減少に関連した海洋循環の変化に伴ったものと考えられ、今後の海洋環境の変化と生態系への影響が危惧される。なお、海氷厚の解析に関しては、コロナ禍により2019～2021年のデータ取得が遅れたことに加え、研究代表者の体調不良により、十分な進展は得られていない。

Research Progress Status

令和4年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和4年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] University of Alaska Fairbanks/University of Washington(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: University of Alaska Fairbanks/University of Washington
• [Journal Article] Backward-tracking simulations of sea ice in the Sea of Okhotsk toward understanding of material transport through sea ice (2024)
  • Author(s): Kuga, M., K. I. Ohshima, S. Kishi, N. Kimura, T. Toyota, J. Nishioka
  • Journal Title: Journal of Oceanography Volume: 80 Pages: 59-70
  • DOI: 10.1007/s10872-023-00706-4
• [Journal Article] A mapping methodology adapted to all polar and subpolar oceans with a stretching/shrinking constraint (2023)
  • Author(s): Mensah, V., K. I. Ohshima
  • Journal Title: Journal of Atmospheric and Oceanic Technology Volume: 40 Pages: 1241-1261
  • DOI: 10.1175/JTECH-D-22-0143.1
• [Journal Article] Particle-tracking experiments of coastal-origin sea ice that could induce high biological productivity in the Sea of Okhotsk (2023)
  • Author(s): Kuga, M., K. I. Ohshima, N. Kimura, K. Nakata, Y. Fukamachi
  • Journal Title: Journal of Oceanography Volume: 79 Pages: 145-159
  • DOI: 10.1007/s10872-022-00670-5
• [Journal Article] Recent state transition of the Arctic Ocean's Beaufort Gyre (2023)
  • Author(s): Peigen Lin,Robert S. Pickart, Harry Heorton, Michel Tsamados, Motoyo Itoh, Takashi Kikuchi
  • Journal Title: Nature Geoscience Volume: 16 Pages: 485-491
  • Peer Reviewed
• [Journal Article] Formation and circulation of newly ventilated winter water in the western Beaufort Sea (2023)
  • Author(s): Peigen Lin, Robert S.Pickart, Thomas J. Weingartner, Harper L. Simmons, Motoyo Itoh, Takashi Kikuchi
  • Journal Title: PROGRESS IN OCEANOGRAPHY Volume: 216 Pages: -
  • DOI: 10.1016/j.pocean.2023.103068
  • Peer Reviewed
• [Journal Article] Floating microplastic inventories in the southern Beaufort Sea, Arctic Ocean (2023)
  • Author(s): Takahito Ikenoue, Ryota Nakajima, Pravakar Mishra, Eswara Venkatesaperumal Ramasamy, Amane Fujiwara, Shigeto Nishino, Akihiko Murata, Eiji Watanabe, Motoyo Itoh
  • Journal Title: Frontiers in marine science Volume: 10 Pages: -
  • DOI: 10.3389/fmars.2023.1288301
  • Peer Reviewed / Open Access
• [Journal Article] An affordable and customizable wave buoy for the study of wave-ice interactions: design concept and results from field deployments (2023)
  • Author(s): Tsubasa Kodaira, Tomotaka Katsuno, Takehiko Nose, Motoyo Itoh, Jean Rabault, Mario Hoppmann, Masafumi Kimizuka & Takuji Waseda
  • Journal Title: COASTAL ENGINEERING JOURNAL Volume: - Pages: -
  • DOI: 10.1080/21664250.2023.2249243
  • Peer Reviewed / Open Access
• [Journal Article] Atlantic-origin water extension into the Pacific Arctic induced an anomalous biogeochemical event (2023)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William J. Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michio Aoyama, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Journal Title: Nature Communications Volume: 14 Pages: -
  • DOI: 10.1038/s41467-023-41960-w
  • Peer Reviewed / Open Access
• [Presentation] Increased heat transport through Barrow Canyon and its impact on subsurface warming in the western Arctic Ocean (2024)
  • Author(s): Motoyo Itoh , Shigeto Nishino and Takashi Kikuchi
  • Organizer: 2024 Ocean Sciences Meeting
• [Presentation] Atlantic-origin water extension into the Pacific Arctic induced an anomalous biogeochemical event (2024)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Organizer: 2024 Ocean Sciences Meeting
• [Presentation] Dissolved Al on the Chukchi Shelf and the shelf slopes in the Canada Basin during the RV Mirai cruises (2024)
  • Author(s): Mariko Hatta,Chris I Measures, Maxime Grand,Amane Fujiwara, Motoyo Itoh
  • Organizer: Ocean Sciences Meeting
• [Presentation] 宗谷暖流域におけるADCP後方散乱強度解析:堆積物の巻き上がりと動物プランクトンの日周鉛直移動 (2023)
  • Author(s): 久賀みづき・大島慶一郎・深町康・伊藤優人・西岡純
  • Organizer: 日本海洋学会2023年度秋季大会
• [Presentation] Trends in sea ice melt in the Baffin Bay and Labrador Sea estimated from ocean observations (2023)
  • Author(s): Mensah, V., M. Ikeda, M. Komatsu, K. I. Ohshima
  • Organizer: International Symposium on Sea Ice across Spatial and Temporal Scale
• [Presentation] A decreasing trend in Bering Sea ice melt revealed by a century-long T-S-based estimate (2023)
  • Author(s): Mensah, V., Y-C. Chen, K. I. Ohshima
  • Organizer: International Symposium on Sea Ice across Spatial and Temporal Scale
• [Presentation] A mapping methodology adapted to all polar and subpolar oceans with a stretching/shrinking constraint (2023)
  • Author(s): Mensah, V., K. I. Ohshima
  • Organizer: 日本海洋学会2023年度秋季大会
• [Presentation] Estimation of ice melt, freshwater budget and their multi-decadal trends in the Baffin Bay and Labrador Sea (2023)
  • Author(s): Mensah, V., K. Fujita, M. Ikeda, M. Komatsu, K. I. Ohshima
  • Organizer: 日本海洋学会2023年度秋季大会
• [Presentation] Century-long T-S-based estimate of sea ice melt in the Pacific Arctic Region (2023)
  • Author(s): Mensah, V., Y-C. Chen, K. I. Ohshima
  • Organizer: Japan Geophysical Union Meeting 2023
• [Presentation] Multidecadal trends of sea ice melt in the Labrador Sea/Baffin Bay revealed by T-S observations (2023)
  • Author(s): Mensah, V., M. Ikeda, M. Komatsu, K. I. Ohshima
  • Organizer: Japan Geophysical Union Meeting 2023
• [Presentation] Beaufort Gyre shrinkage and Atlantification induced an anomalous biogeochamical event in the western Arctic Ocean (2023)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michio Aoyama, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Organizer: Siberian DBO Workshop, International Symposium on Polar Science 2023 (ISPS 2023)
  • Invited
• [Presentation] チュクチ海北方域における太平洋夏季水の輸送に伴う亜表層貯熱量の増加過程 (2023)
  • Author(s): 村松 美幌，上野 洋路，渡邉 英嗣，伊東 素代，小野寺 丈尚太郎，溝端 浩平
  • Organizer: 日本地球惑星科学連合大会 (JpGU)
• [Presentation] SAS-Mirai 2020-2022 cruises in the western Arctic Ocean (Cruises Review by Chief Scientists) (2023)
  • Author(s): Shigeto Nishino, Amane Fujiwara, Motoyo Itoh
  • Organizer: International SAS Synthesis Workshop
• [Presentation] Beaufort Gyre shrinkage and Atlantification induced an anomalous biogeochamical event in the western Arctic Ocean (2023)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michio Aoyama, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Organizer: International SAS Synthesis Workshop
• [Presentation] Decadal condition changes in material transportation in the southwestern Canada Basin, 2010-2021 (2023)
  • Author(s): Jonaotaro Onodera, Eiji Watanabe, Kohei Mizobata, Miaki Muramatsu, Motoyo Itoh, Katsunori Kimoto, Yuichiro Tanaka, Eun-Jin Yang, Naomi Harada, Takashi Kikuchi
  • Organizer: Ecosystem Studies of Subarctic and Arctic Seas (ESSAS) 2023 Annual Science Meeting
• [Presentation] 北極海太平洋側への大西洋起源水の貫入に起因する低酸素化・酸性化 (2023)
  • Author(s): 西野茂人、Jinyoung Jung、Kyoung-Ho Cho、William J. Williams、藤原周、村田昌彦、伊東素代、 渡邉英嗣、川合美千代、菊地隆、Eun Jin Yang、Sung-Ho Kang
  • Organizer: 日本海洋学会2023年度秋季大会
• [Presentation] Increased heat transport through Barrow Canyon and its impact on subsurface warming in the western Arctic Ocean (2023)
  • Author(s): Motoyo Itoh , Shigeto Nishino and Takashi Kikuchi
  • Organizer: Pacific Arctic Group (PAG) 2023 Fall Meeting
• [Presentation] Atlantic-origin water extension into the Pacific Arctic induced an anomalous biogeochemical event (2023)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michio Aoyama, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Organizer: Pacific Arctic Group (PAG) 2023 Fall Meeting
• [Presentation] Atlantic-origin water extension into the Pacific Arctic induced an anomalous biogeochemical event (2023)
  • Author(s): Shigeto Nishino, Jinyoung Jung, Kyoung-Ho Cho, William Williams, Amane Fujiwara, Akihiko Murata, Motoyo Itoh, Eiji Watanabe, Michiyo Yamamoto-Kawai, Takashi Kikuchi, Eun Jin Yang, Sung-Ho Kang
  • Organizer: K-INET International Symposium 2023, Environmental Issues in a Post-Covid 19 Society
• [Presentation] 北極海バロー海底谷における表層混合層の時系列観測 (2023)
  • Author(s): 伊東素代
  • Organizer: 日本海洋学会2023年度秋季大会
• [Presentation] Decadal changes in material transportation in the southwestern Canada Basin, 2010-2022 (2023)
  • Author(s): Jonodera Onodera, Eiji Watanabe, Kohei Mizobata, Miaki Muramatsu, Motoyo Itoh, Yuichiro Tanaka, Eun Jin Yang, Naomi Harada, and Takashi Kikuchi
  • Organizer: PAG (Pacific Arctic Group) Fall Meeting 2023
• [Book] 北極域の研究―その現状と将来構想― ・太平洋水の熱・流量フラックスの変化 (2024)
  • Author(s): motoyo Itoh
  • Total Pages: 480
  • Publisher: 海文堂出版
  • ISBN: 978-4-303-56230-4