教育活動

大学院　海洋技術環境学専攻：海洋データサイエンス、気象海象学基礎、海洋技術環境学プロジェクトI, II
学部　　力学演習IA/2A、流体力学演習A1、基礎プロジェクト、応用プロジェクト、領域プロジェクト 　　　　現代工学基礎Ⅰ、

研究活動

1) 持続可能な海洋開発を支援する海洋モデルの開発
持続可能な海洋開発と海洋保全には、限られた情報から海洋環境の再現を行い、海洋環境を把握することが必要不可欠です。最も多くの海洋情報を提供するのは観測と数値モデルをデータ同化技術によって統合した再解析と呼ばれるデータプロダクトですが、空間解像度は10km程度に留まり特定海域での活動を考察するには不十分です。我々は任意の海域で詳細な海洋情報を創出する海洋モデルの開発に取り組んでいます。
2) 自律分散型観測による海洋情報の飛躍的な増加
現在、全球準リアルタイム海洋観測網として4000基のアルゴフロートが運用されていますが広大な海洋では数100kmに1つの観測点に留まります。また、極域では海氷に阻まれ観測点が不足しています。自律分散的に海洋データを収集し海洋情報を飛躍的に増加させるシステムを構築することで、洋上風力発電、ブルーカーボン、極域を含む海洋の持続的な利用の実現に貢献します。

3) 気候変動を駆動する海氷と小規模渦、海洋内部波
北極海の夏季海氷域面積の減少は顕著な温暖化の証拠とされる一方で、根本となる海氷融解プロセスの全容は未解明です。そこで、融解期の強風下で確認された海氷の急速融解事例に着目し、その機構解明とモデル化を行います。得られた結果は短中期的な海氷予測の高精度化に貢献し、最終的に脱炭素に資するとされる北極航路の利用に活用されます。

文献

1. Yasushi Fujiwara, Takuji Waseda, Tsubasa Kodaira, Takehiko Nose, Tomotaka Katsuno, Koya Sato, 2025: Ice particle grouping under waves: Experimental investigation of the initial stage of pancake ice formation. Cold Regions Science and Technology, 233, 104449.
2. Eiji Watanabe, Hiromichi Ueno, Tsubasa Kodaira, Akihiko Murata, Shigeto Nishino, Takahito Ikenoue, Masanobu Yamamoto, Daiki Nomura, Hiroto Abe, Yusuke Kawaguchi, Daisuke Hirano, Yuanxin Zhang, Sayaka Yasunaka, 2025: Arctic marine environments regulated by ocean transport and air–sea–land interaction: Findings from the ArCS II Ocean Research Program. Polar Science, 101205.
3. Takehiko Nose, Tomotaka Katsuno, Takuji Waseda, Shuki Ushio, Jean Rabault, Tsubasa Kodaira, Joey Voermans, 2023: Observation of wave propagation over 1,000 km into Antarctica winter pack ice. Coastal Engineering Journal, 1–17.
4. Tsubasa Kodaira, Tomotaka Katsuno, Takehiko Nose, Motoyo Itoh, Jean Rabault, Mario Hoppmann, Masafumi Kimizuka, Takuji Waseda, 2023: An affordable and customizable wave buoy for the study of wave-ice interactions: design concept and results from field deployments. Coastal Engineering Journal, 1–15.
5. Takehiko Nose, Jean Rabault, Takuji Waseda, Tsubasa Kodaira, Yasushi Fujiwara, Tomotaka Katsuno, Naoya Kanna, Kazutaka Tateyama, Joey Voermans, Tatiana Alekseeva, 2023: A comparison of an operational wave–ice model product and drifting wave buoy observation in the central Arctic Ocean. Polar Research, 42.
6. Tsubasa Kodaira, Kaushik Sasmal, Rei Miratsu, Tsutomu Fukui, Tingyao Zhu, Takuji Waseda, 2023: Uncertainty in wave hindcasts in the North Atlantic Ocean. Marine Structures, 89, 103370.
7. Rei Miratsu, Kaushik Sasmal, Tsubasa Kodaira, Tsutomu Fukui, Tingyao Zhu, Takuji Waseda, 2022: Evaluation of ship operational effect based on long-term encountered sea states using wave hindcast combined with storm avoidance model. Marine Structures, 86, 103293.
8. Takuji Waseda, Alberto Alberello, Takehiko Nose, Takenobu Toyota, Tsubasa Kodaira, Yasushi Fujiwara, 2022: Observation of anomalous spectral downshifting of waves in the Okhotsk Sea Marginal Ice Zone. Philosophical Transactions of the Royal Society A, 380(2235).
9. Pengcheng Wang, Natacha B. Bernier, Keith R. Thompson, Tsubasa Kodaira, 2021: Evaluation of a global total water level model in the presence of radiational S2 tide. Ocean Modelling, 168, 101893.
10. Kaushik Sasmal, Rei Miratsu, Tsubasa Kodaira, Tsutomu Fukui, Tingyao Zhu, Takuji Waseda, 2021: Statistical model representing storm avoidance by merchant ships in the North Atlantic Ocean. Ocean Engineering, 235, 109163.
11. Joey J. Voermans, Qingxiang Liu, Aleksey Marchenko, Jean Rabault, Kirill Filchuk, Ivan Ryzhov, Petra Heil, Takuji Waseda, Takehiko Nose, Tsubasa Kodaira, Jingkai Li, Alexander V. Babanin, 2021: Wave dispersion and dissipation in landfast ice: comparison of observations against models. [Journal name missing]
12. Takuji Waseda, Shogo Watanabe, Wataru Fujimoto, Takehiko Nose, Tsubasa Kodaira, Amin Chabchoub, 2021: Directional Coherent Wave Group From an Assimilated Non-linear Wavefield. Frontiers in Physics, 9.
13. Takuji Waseda, Takehiko Nose, Tsubasa Kodaira, Kaushik Sasmal, Adrean Webb, 2020: Climatic trends of extreme wave events caused by Arctic Cyclones in the western Arctic Ocean. Polar Science, 100625.
14. Tsubasa Kodaira, Takuji Waseda, Takehiko Nose, Jun Inoue, 2020: Record high Pacific Arctic seawater temperatures and delayed sea ice advance in response to episodic atmospheric blocking. Scientific Reports, 10(1).
15. Takehiko Nose, Takuji Waseda, Tsubasa Kodaira, Jun Inoue, 2020: On the coagulated pancake ice formation: Observation in the refreezing Chukchi Sea and comparison to the Antarctic consolidated pancake ice. Polar Science, 27, 100622.
16. Tsubasa Kodaira, Takuji Waseda, Takehiko Nose, Kazutoshi Sato, Jun Inoue, Joey Voermans, Alexander Babanin, 2020: Observation of on-ice wind waves under grease ice in the western Arctic Ocean. Polar Science, 27, 100567.
17. Takehiko Nose, Takuji Waseda, Tsubasa Kodaira, Jun Inoue, 2020: Satellite-retrieved sea ice concentration uncertainty and its effect on modelling wave evolution in marginal ice zones. The Cryosphere, 14(6), 2029–2052.
18. Tsubasa Kodaira, Takuji Waseda, 2019: Tidally generated island wakes and surface water cooling over Izu Ridge. Ocean Dynamics, 69(11–12), 1373–1385.
19. John T. Imamura, Ken Takagi, Takuji Waseda, Tsubasa Kodaira, 2019: Comparison of Numerical Simulations and Field Measurements of Current Flow in the Tokara Strait. OCEANS 2018 MTS/IEEE Charleston.
20. Shogo Watanabe, Wataru Fujimoto, Tak Nose, Tsubasa Kodaira, Graham Davies, Daniel Lechner, Takuji Waseda, 2019: Data assimilation of the stereo reconstructed wave fields to a nonlinear phase resolved wave model. OMAE Proceedings, Vol. 9.
21. Tsubasa Kodaira, Ryota Wada, Daimon Wada, Shogo Watanabe, Yuki Kita, Takuji Waseda, 2019: Development and Demonstration of a Low-Cost Coastal Wind Observation System. Journal of the Japan Society of Naval Architects and Ocean Engineers, 29, 163–169.
22. Yu-Lin K. Chang, Yasumasa Miyazawa, Tsubasa Kodaira, Swadhin Behera, 2018: Philippines–Taiwan Oscillations and its connection to tropical cyclone frequency in the western North Pacific Ocean. Scientific Reports, 8(1).
23. Tsubasa Kodaira, Takuji Waseda, 2018: ADCP observation and numerical model prediction of tidal currents near Kozu Island. OMAE Proceedings, Vol. 10.
24. Yu-Lin Chang, Yasumasa Miyazawa, Lie-Yauw Oey, Tsubasa Kodaira, Shihming Huang, 2017: The formation processes of phytoplankton growth and decline in mesoscale eddies in the western North Pacific Ocean. Journal of Geophysical Research: Oceans, 122(5), 4444–4455.
25. 小平 翼, 和田 良太, 早稲田 卓爾, 2017: 日本沿岸潮流発電の資源量推定に対する潮流の長期変動の影響. 日本船舶海洋工学会論文集, 25, 151–156.
26. Tsubasa Kodaira, Keith R. Thompson, Natacha B. Bernier, 2016: The effect of density stratification on the prediction of global storm surges. Ocean Dynamics, 66(12), 1733–1743.
27. Tsubasa Kodaira, Takuji Waseda, Motoyasu Miyata, Wooyoung Choi, 2016: Internal solitary waves in a two-fluid system with a free surface. Journal of Fluid Mechanics, 804, 201–223.
28. Tsubasa Kodaira, Keith R. Thompson, Natacha B. Bernier, 2016: Prediction of M2 tidal surface currents by a global baroclinic ocean model and evaluation using observed drifter trajectories. Journal of Geophysical Research: Oceans, 121(8), 6159–6183.
29. K. Kiyomatsu, Y. Kadomoto, T. Kodaira, T. Waseda, K. Takagi, S. M. Verlamov, Y. Miyazawa, 2015: ADCP measurements of ocean currents near Miyake island for a Kuroshio energy converter development project. RENEW 2014, 161–168.
30. Tsubasa Kodaira, Takuji Waseda, Yasumasa Miyazawa, 2014: Nonlinear internal waves generated and trapped upstream of islands in the Kuroshio. Geophysical Research Letters, 41(14), 5091–5098.
31. 清松 啓司, 小平 翼, 門元 之郎, 早稲田 卓爾, 高木 健, 2014: 三宅島近海流況観測とそれに基づく海流エネルギー資源量推定. 日本船舶海洋工学会論文集, 20, 147–155.
32. Tsubasa Kodaira, Takuji Waseda, Tetsuji Nakagawa, Osamu Isoguchi, Yasumasa Miyazawa, 2013: Measuring the Kuroshio Current Around Miyake Island, a Potential Site for Ocean-Current Power Generation. International Journal of Offshore and Polar Engineering, 23(4), 272–278.

将来計画

脱炭素社会に向けた海洋デジタルツインの構築
高精度な観測と数値モデルを統合し、海洋環境の再現・予測を行うとともに、関連するデータを統合して持続可能な海洋開発ならびに海洋を利用した脱炭素技術導入に関する意思決定支援ツールとなる海洋デジタルツインの構築を目指します。数値海洋モデルを取り扱うだけではなく、関連する海洋情報との統合ならびに活用を重視して、海洋再生可能エネルギー導入の加速やブルーカーボン分野に貢献します。

教員からのメッセージ

一歩踏み出し、継続的に取り組み、自分に自信を持つ。大学院はそんな場所であって欲しいと考えています。

ホームページのURL

http://www.orca.k.u-tokyo.ac.jp/WasedaLab/