Development of ocean simulation with focus on the Totten Ice Shelf

• Project/Area Number: 19K23447
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0204:Astronomy, earth and planetary science, and related fields
• Research Institution: Hokkaido University
• Principal Investigator: NAKAYAMA Yoshihiro 北海道大学, 低温科学研究所, 助教 (30840201)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 南大洋 / 南極 / 海面上昇 / 棚氷 / 融解

Outline of Research at the Start

東南極に位置するトッテン氷河は、氷河流動が加速していることが指摘され、将来的に大きく海面上昇に寄与する可能性がある。氷河流動加速の主な原因は、トッテン棚氷下部への暖かい水塊（周極深層水）の流入による棚氷融解の加速である。本研究では、海洋/氷床観測データと海洋数値モデルを統合的に利用し、より現実に近く海洋を再現するという新たに確立されつつある手法を用いて、トッテン棚氷域の海洋数値モデルを開発する。

Outline of Final Research Achievements

East Antarctica's Totten Glacier has recently been melting at an alarming rate. In this study, we develop a regional East Antarctic configuration of the Massachusetts Institute of Technology general circulation model (MITgcm) and simulate ocean heat intrusions towards the Totten ice shelf. We demonstrate that Antarctic Slope Current (ASC) has a blocking effect and ASC weakening leads to on-shelf intrusions, which may control the Totten ice shelf melt rate.

Academic Significance and Societal Importance of the Research Achievements

南極沿岸域の中で、特に、観測データ、数値モデル研究ともに、ほとんど実施されてこなかった、東南極沿岸トッテン氷河/棚氷沖における棚氷下部へ向かった高温の水塊の流入メカニズムを新たに示唆した点が学術的に意義がある。これらの海域における棚氷融解のメカニズムはこれまで、あまりよくわかっておらず、南極沿岸流と高温の水塊の陸だな上への流入の強い関係性が見つかったことは、さらに全球的な大気や海洋循環との関係性を明らかにするステップとなる。さらに、全球モデルなど、より低解像度、長期間のシミュレーションである気候モデルにおける海洋循環や海水準といった全球環境将来予測スキルの発展に資する。

Research Products

• [Int'l Joint Research] University of California Irvine/Jet Propulsion Laboratory/Scripps Institution of Oceanography(米国)
• [Int'l Joint Research] Alfred Wegener Institute(ドイツ)
• [Int'l Joint Research] University of California Irvine/NASA Jet Propulsion Laboratory(米国)
• [Journal Article] Impact of West Antarctic ice shelf melting on Southern Ocean hydrography (2020)
  • Author(s): Nakayama Yoshihiro, Timmermann Ralph, H. Hellmer Hartmut
  • Journal Title: The Cryosphere Volume: 14 Issue: 7 Pages: 2205-2216
  • DOI: 10.5194/tc-14-2205-2020
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Pathways of ocean heat towards Pine Island and Thwaites grounding lines (2019)
  • Author(s): Nakayama Y., Manucharyan M., Zhang H.., Dutrieux P., Torres H., Klein P., Seroussi H., Shodlok M., Rignot E., Menemenlis D.
  • Journal Title: Scientific Report Volume: 9 Issue: 1 Pages: 1-9
  • DOI: 10.1038/s41598-019-53190-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] The development of East Antarctic ocean simulation with a focus on the Totten Glacier (2020)
  • Author(s): Yoshihiro Nakayama, Chad A Greene, Fernando S Paolo, Dustin Carroll, Dimitris Menemenlis, Hong Zhang, Tyler Pelle, Mathieu Morlighem, Vigan Mensah, Haruhiko Kashiwase, Daisuke Simizu, Jamin Stevens Greenbaum, Donald D Blankenship, Ayako Abe-Ouchi, Shigeru Aoki
  • Organizer: AGU Fall Meeting 2020, Online
  • Int'l Joint Research
• [Presentation] Modeling Ice-shelf ocean interactions of West Antarctic and East Antarctic ice shelves (2020)
  • Author(s): Yoshihiro Nakayama, Hong Zhang, Vigan Mensah, Shuntraro Hyogo, Shigeru Aoki
  • Organizer: West Antarctic Ice Sheet (WAIS) workshop 2021, Virtual
  • Int'l Joint Research
• [Presentation] Modeling Ice-shelf ocean interactions of West Antarctic and East Antarctic ice shelves (2020)
  • Author(s): Yoshihiro Nakayama, Hong Zhang, Vigan Mensah, Shigeru Aoki, Dimitris Menemenlis
  • Organizer: JpGU-AGU Joint Meeting 2020, Virtual Meeting
  • Int'l Joint Research
• [Presentation] Modeling Ice-shelf ocean interactions of West Antarctic and East Antarctic ice shelves (2020)
  • Author(s): Yoshihiro Nakayama, Hong Zhang, Vigan Mensah, Shuntraro Hyogo, Shigeru Aoki
  • Organizer: Forum for Research into Ice Shelf Processes (FRISP), Online
  • Int'l Joint Research
• [Presentation] Origin of Circumpolar Deep Water intruding onto the Amundsen and Bellingshausen Sea continental shelves (2019)
  • Author(s): Nakayama Y., Menemenlis D., Shodlok M., Rignot E.
  • Organizer: Japan Geophysical Union 2019
• [Presentation] Pathways of ocean heat towards Pine Island and Thwaites grounding lines (2019)
  • Author(s): Nakayama, Y., Manucharyan G., Zhang H., Dutrieux P., Torres H. S., Klein P., Serrousi H., Shodlok M., Rignot E.
  • Organizer: Forum for Research into Ice Shelf Processes 2019
  • Int'l Joint Research