東北大学研究者紹介 - 髙須賀　大輔

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顔写真

タカスカ　ダイスケ

髙須賀　大輔

Daisuke Takasuka

所属

大学院理学研究科　地球物理学専攻　流体地球物理学講座（気象学・大気力学分野）

職名

助教

学位

博士（理学）（東京大学）

researchmap

https://researchmap.jp/dtakasuka

J-GLOBAL ID

202401001820909536

e-Rad 研究者番号

71001666

ORCID

https://orcid.org/0000-0002-9321-6403

経歴 4

2024年4月～継続中

東北大学　大学院理学研究科地球物理学専攻　助教
2022年10月～ 2024年3月

東京大学　大気海洋研究所気候システム研究系　特任助教
2021年4月～ 2022年10月

国立研究開発法人海洋研究開発機構　地球環境部門環境変動予測研究センター　ポストドクトラル研究員
2020年4月～ 2021年3月

お茶の水女子大学　基幹研究院　日本学術振興会特別研究員（PD）

委員歴 6

World Climate Research Programme (WCRP)　Co-chairs of the Digital Earths Lighthouse Activity working group on km-scale modeling

2026年3月～継続中
Global Energy and Water Exchanges (GEWEX)　Co-Leader of the GEWEX/GASS Diurnal Cycle of Precipitation Project

2025年11月～継続中
日本気象学会　松野賞候補者推薦委員会

2024年7月～継続中
日本気象学会　国際学術交流委員会

2024年7月～継続中
日本気象学会　英文レター誌SOLA 編集委員

2024年7月～継続中
World Meteorological Organization, Working Group on Numerical Experimentation　MJO Task Force member

2023年4月～継続中

︎全件表示 ︎最初の5件までを表示

研究分野 1

自然科学一般 / 大気水圏科学 /

受賞 4

Early career researcher competition winner

2024年7月　World Climate Research Programme (WCRP), GEWEX
松野賞

2019年7月　日本気象学会
学生優秀発表賞

2019年5月　日本地球惑星科学連合
研究奨励賞（修士）

2017年3月　東京大学大学院理学系研究科

論文 25

Resolution dependence of the climate feedback parameter in km-scale climate models

Angel Peinado Bravo, Masaki Toda, Hauke Schmidt, Sandrine Bony, Sarah M. Kang, Daniel Klocke, Lukas Kluft, Bjorn Stevens, Daisuke Takasuka, Angel Peinado Bravo

2026年6月9日

DOI： 10.22541/essoar.15004534/v1 　
Hacking Km-Scale Models: A Participative Model for Climate Information 査読有り

Andrew Gettelman, Pier Luigi Vidale, Bjorn Stevens, Florian Ziemen, Zhe Feng, Heike Konow, Tobias Kölling, Lukas Kluft, William Jones, Sara Pasqualetto, Yuting Wu, Saskia Brose, John Clyne, Lluís Fita, Samuel Green, Lucas Harris, Melissa Anne Hart, Julia Kukulies, Brian Medeiros, Timothy M. Merlis, Mark Muetzelfeldt, Robert Pincus, Rosmeri P. da Rocha, Masaki Satoh, Hang Su, Daisuke Takasuka, Chris Terai, Paul Ullrich, Tianjun Zhou

Bulletin of the American Meteorological Society　2026年4月28日
出版者・発行元： American Meteorological Society
DOI： 10.1175/bams-d-25-0183.1 　

ISSN：0003-0007

eISSN：1520-0477

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Abstract In May 2025 nearly 700 participants from all around the world coalesced at 10 regional nodes, and a few satellite nodes, to take part in a global hackathon of km-scale (horizontal grid spacing < 10 km) regional and global Earth System Models. Exciting science is emerging from these efforts, ranging across novel model analysis, new ways of integrating with satellite data, and emulation with machine learning. New technologies were trialed that enable the community to work in new and complementary ways to democratize access to global information at a local scale from a set of the world's highest-resolution climate models. The hackathon demonstrated how exascale data can be organized to be accessible to anyone. Fundamentally, the community could apply these techniques and technologies to move towards more participative models for co-production and delivery of diverse sources of climate information for climate scientists and citizens alike.
Climate and ocean circulation changes toward a modern snowball Earth 査読有り

Takashi Obase, Takanori Kodama, Takao Kawasaki, Sam Sherriff-Tadano, Daisuke Takasuka, Ayako Abe-Ouchi, Masakazu Fujii

Climate of the Past　22　845-859　2026年4月20日

DOI： 10.5194/cp-22-845-2026 　
Machine learning prediction of the Madden–Julian oscillation using reservoir computing 査読有り

Tamaki Suematsu, Kengo Nakai, Tsuyoshi Yoneda, Daisuke Takasuka, Takuya Jinno, Yoshitaka Saiki, Hiroaki Miura

Japan Journal of Industrial and Applied Mathematics　43　(2)　2026年3月19日
出版者・発行元： Springer Science and Business Media LLC
DOI： 10.1007/s13160-026-00770-5 　

ISSN：0916-7005

eISSN：1868-937X

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Abstract The prediction of the Madden–Julian Oscillation (MJO), a massive tropical weather event with global socio-economic impacts, has been infamously difficult with physics-based weather prediction models. We employ the reservoir computing, a brain-inspired machine-learning technique, to construct a machine learning model that forecasts the real-time multivariate MJO index (RMM), a macroscopic variable that represents the state of the MJO. The training data was refined by development of a novel real-time band-pass filter that extracts the recurrency of MJO signals only from the past raw atmospheric data, and by selection of a suitable time-delay coordinate of the RMM that enhances the recurrency of the input data. The constructed model demonstrated the skill to forecast the time sequence of the RMM for a month from pre-developmental stages of the MJO. Examination of best-performing cases suggested that RMM sequences may be predicted for over two months in some cases. These results imply that inherent predictability limit of the MJO is longer than that has been estimated from physics-based weather prediction models.
Precipitation Characteristics and Thermodynamic‐Convection Coupling in Global Kilometer‐Scale Simulations 査読有り

Daisuke Takasuka, Tobias Becker, Jiawei Bao

Journal of Advances in Modeling Earth Systems　2026年3月

DOI： 10.1029/2025MS005343 　
Propagation of the Madden–Julian oscillation as a deterministic chaotic phenomenon 査読有り

Daisuke Takasuka, Tamaki Suematsu, Hiroaki Miura, Masuo Nakano

Science Advances　2026年2月18日

DOI： 10.1126/sciadv.adz1916 　
Tropics-wide intraseasonal oscillations 査読有り

Jiawei Bao, Sandrine Bony, Daisuke Takasuka, Caroline Muller

Proceedings of the National Academy of Sciences　122　(48)　2025年11月24日
出版者・発行元： Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2511549122 　

ISSN：0027-8424

eISSN：1091-6490

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The tropical climate variability is characterized by various oscillations across a range of timescales. Oscillations that imprint the tropical mean state are generally attributed to slow processes, such as the seasonal cycle or interannual variability. Here, we identify a pronounced tropics-wide intraseasonal oscillation (TWISO) in satellite observations and reanalyses. This oscillation, with a period of 30 to 60 d, is evident across multiple variables and involves interactions between convection, radiation, surface fluxes, and large-scale circulation. It is primarily manifested as convective perturbations in the tropical Indo-Pacific warm pool accompanied by oscillations in the large-scale tropical overturning circulation. Here, we examine the relationship between TWISO, the Madden–Julian Oscillation (MJO), and the instability of radiative-convective equilibrium. Certain phases of TWISO coincide with specific phases of the MJO, suggesting a potential connection between the two. However, although the MJO can amplify the oscillation amplitude of TWISO, it is not essential for TWISO to occur. Finally, due to its broad manifestation across the tropics, TWISO potentially exerts widespread influence on tropical weather and climate at regional scales.
nextGEMS: entering the era of kilometer-scale Earth system modeling 査読有り

Hans Segura, Xabier Pedruzo-Bagazgoitia, Philipp Weiss, Sebastian K. Müller, Thomas Rackow, Junhong Lee, Edgar Dolores-Tesillos, Imme Benedict, Matthias Aengenheyster, Razvan Aguridan, Gabriele Arduini, Alexander J. Baker, Jiawei Bao, Swantje Bastin, Eulàlia Baulenas, Tobias Becker, Sebastian Beyer, Hendryk Bockelmann, Nils Brüggemann, Lukas Brunner, Suvarchal K. Cheedela, Sushant Das, Jasper Denissen, Ian Dragaud, Piotr Dziekan, Madeleine Ekblom, Jan Frederik Engels, Monika Esch, Richard Forbes, Claudia Frauen, Lilli Freischem, Diego García-Maroto, Philipp Geier, Paul Gierz, Álvaro González-Cervera, Katherine Grayson, Matthew Griffith, Oliver Gutjahr, Helmuth Haak, Ioan Hadade, Kerstin Haslehner, Shabeh ul Hasson, Jan Hegewald, Lukas Kluft, Aleksei Koldunov, Nikolay Koldunov, Tobias Kölling, Shunya Koseki, Sergey Kosukhin, Josh Kousal, Peter Kuma, Arjun U. Kumar, Rumeng Li, Nicolas Maury, Maximilian Meindl, Sebastian Milinski, Kristian Mogensen, Bimochan Niraula, Jakub Nowak, Divya Sri Praturi, Ulrike Proske, Dian Putrasahan, René Redler, David Santuy, Domokos Sármány, Reiner Schnur, Patrick Scholz, Dmitry Sidorenko, Dorian Spät, Birgit Sützl, Daisuke Takasuka, Adrian Tompkins, Alejandro Uribe, Mirco Valentini, Menno Veerman, Aiko Voigt, Sarah Warnau, Fabian Wachsmann, Marta Wacławczyk, Nils Wedi, Karl-Hermann Wieners, Jonathan Wille, Marius Winkler, Yuting Wu, Florian Ziemen, Janos Zimmermann, Frida A.-M. Bender, Dragana Bojovic, Sandrine Bony, Simona Bordoni, Patrice Brehmer, Marcus Dengler, Emanuel Dutra, Saliou Faye, Erich Fischer, Chiel van Heerwaarden, Cathy Hohenegger, Heikki Järvinen, Markus Jochum, Thomas Jung, Johann H. Jungclaus, Noel S. Keenlyside, Daniel Klocke, Heike Konow, Martina Klose, Szymon Malinowski, Olivia Martius, Thorsten Mauritsen, Juan Pedro Mellado, Theresa Mieslinger, Elsa Mohino, Hanna Pawłowska, Karsten Peters-von Gehlen, Abdoulaye Sarré, Pajam Sobhani, Philip Stier, Lauri Tuppi, Pier Luigi Vidale, Irina Sandu, Bjorn Stevens

Geoscientific Model Development　18　(20)　7735-7761　2025年10月23日
出版者・発行元： Copernicus GmbH
DOI： 10.5194/gmd-18-7735-2025 　

eISSN：1991-9603

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Abstract. The Next Generation of Earth Modeling Systems (nextGEMS) project aimed to produce multidecadal climate simulations, for the first time, with resolved kilometer-scale (km-scale) processes in the ocean, land, and atmosphere. In only 3 years, nextGEMS achieved this milestone with the two km-scale Earth system models, ICOsahedral Non-hydrostatic model (ICON) and Integrated Forecasting System coupled to the Finite-volumE Sea ice-Ocean Model (IFS-FESOM). nextGEMS was based on three cornerstones: (1) developing km-scale Earth system models with small errors in the energy and water balance, (2) performing km-scale climate simulations with a throughput greater than 1 simulated year per day, and (3) facilitating new workflows for an efficient analysis of the large simulations with common data structures and output variables. These cornerstones shaped the timeline of nextGEMS, divided into four cycles. Each cycle marked the release of a new configuration of ICON and IFS-FESOM, which were evaluated at hackathons. The hackathon participants included experts from climate science, software engineering, and high-performance computing as well as users from the energy and agricultural sectors. The continuous efforts over the four cycles allowed us to produce 30-year simulations with ICON and IFS-FESOM, spanning the period 2020–2049 under the SSP3-7.0 scenario. The throughput was about 500 simulated days per day on the Levante supercomputer of the German Climate Computing Center (DKRZ). The simulations employed a horizontal grid of about 5 km resolution in the ocean and 10 km resolution in the atmosphere and land. Aside from this technical achievement, the simulations allowed us to gain new insights into the realism of ICON and IFS-FESOM. Beyond its time frame, nextGEMS builds the foundation of the Climate Change Adaptation Digital Twin developed in the Destination Earth initiative and paves the way for future European research on climate change.
What Is the Role of Air-Sea Interaction in the Intra-Seasonal Fluctuation of the Monsoon Trough over the Western North Pacific? 査読有り

Yutaro NIRASAWA, Tomoki MIYAKAWA, Daisuke TAKASUKA, Takao KAWASAKI, Ryusuke MASUNAGA

Journal of the Meteorological Society of Japan. Ser. II　103　(6)　679-706　2025年9月
出版者・発行元： Meteorological Society of Japan
DOI： 10.2151/jmsj.2025-035 　

ISSN：0026-1165

eISSN：2186-9057
ENSO and QBO Controls the Favorableness of the MJO Realization Cooperatively 査読有り

Daisuke Takasuka, Tsubasa Kohyama, Tamaki Suematsu, Hiroaki Miura

Journal of Geophysical Research: Atmospheres　130　(2)　2025年1月28日

DOI： 10.1029/2024JD042116 　
Multi-year simulations at kilometre scale with the Integrated Forecasting System coupled to FESOM2.5 and NEMOv3.4 査読有り

Thomas Rackow, Xabier Pedruzo-Bagazgoitia, Tobias Becker, Sebastian Milinski, Irina Sandu, Razvan Aguridan, Peter Bechtold, Sebastian Beyer, Jean Bidlot, Souhail Boussetta, Willem Deconinck, Michail Diamantakis, Peter Dueben, Emanuel Dutra, Richard Forbes, Rohit Ghosh, Helge F. Goessling, Ioan Hadade, Jan Hegewald, Thomas Jung, Sarah Keeley, Lukas Kluft, Nikolay Koldunov, Aleksei Koldunov, Tobias Kölling, Josh Kousal, Christian Kühnlein, Pedro Maciel, Kristian Mogensen, Tiago Quintino, Inna Polichtchouk, Balthasar Reuter, Domokos Sármány, Patrick Scholz, Dmitry Sidorenko, Jan Streffing, Birgit Sützl, Daisuke Takasuka, Steffen Tietsche, Mirco Valentini, Benoît Vannière, Nils Wedi, Lorenzo Zampieri, Florian Ziemen

Geoscientific Model Development　18　(1)　33-69　2025年1月10日
出版者・発行元： Copernicus GmbH
DOI： 10.5194/gmd-18-33-2025 　

eISSN：1991-9603

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Abstract. We report on the first multi-year kilometre-scale global coupled simulations using ECMWF's Integrated Forecasting System (IFS) coupled to both the NEMO and FESOM ocean–sea ice models, as part of the H2020 Next Generation Earth Modelling Systems (nextGEMS) project. We focus mainly on an unprecedented IFS-FESOM coupled setup, with an atmospheric resolution of 4.4 km and a spatially varying ocean resolution that reaches locally below 5 km grid spacing. A shorter coupled IFS-FESOM simulation with an atmospheric resolution of 2.8 km has also been performed. A number of shortcomings in the original numerical weather prediction (NWP)-focused model configurations were identified and mitigated over several cycles collaboratively by the modelling centres, academia, and the wider nextGEMS community. The main improvements are (i) better conservation properties of the coupled model system in terms of water and energy budgets, which also benefit ECMWF's operational 9 km IFS-NEMO model; (ii) a realistic top-of-the-atmosphere (TOA) radiation balance throughout the year; (iii) improved intense precipitation characteristics; and (iv) eddy-resolving features in large parts of the mid- and high-latitude oceans (finer than 5 km grid spacing) to resolve mesoscale eddies and sea ice leads. New developments at ECMWF for a better representation of snow and land use, including a dedicated scheme for urban areas, were also tested on multi-year timescales. We provide first examples of significant advances in the realism and thus opportunities of these kilometre-scale simulations, such as a clear imprint of resolved Arctic sea ice leads on atmospheric temperature, impacts of kilometre-scale urban areas on the diurnal temperature cycle in cities, and better propagation and symmetry characteristics of the Madden–Julian Oscillation.
A protocol and analysis of year-long simulations of global storm-resolving models and beyond 査読有り

Daisuke Takasuka, Masaki Satoh, Tomoki Miyakawa, Chihiro Kodama, Daniel Klocke, Bjorn Stevens, Pier Luigi Vidale, Christopher R. Terai

Progress in Earth and Planetary Science　11　(1)　2024年12月19日
出版者・発行元： Springer Science and Business Media LLC
DOI： 10.1186/s40645-024-00668-1 　

eISSN：2197-4284

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Abstract We propose a protocol to evaluate and analyze year-long simulations of global storm-resolving models (GSRMs). The proposed protocol complements an earlier 40-day simulation protocol under the DYAMOND (DYnamics of the Atmospheric general circulation Modeled On Non-hydrostatic Domains) project to allow the analysis of the seasonal cycle and associated climatic relevant phenomena. This intercomparison aims to reveal how GSRMs, which can simulate mesoscale convective systems (MCSs) in the global domain, reproduce atmospheric large-scale structures related to convection beyond month-long simulations. The intercomparison for one-year simulations is conducted by either atmosphere-only models or atmosphere–ocean coupled models with atmospheric horizontal mesh sizes less than 5 km. We recommend the continuous four seasons from March 2020 to February 2021 as a target period for the intercomparison but with options for many groups to join more flexibly. The output variables are collected at 0.25° resolution, and archives of a small set of native grid variables are encouraged to analyze tropical cyclones and MCSs. Through the proposed global storm-resolving simulation, we will evaluate the climatological distributions of the atmospheric large-scale circulations, such as the Intertropical Convergence Zone (ITCZ), monsoon, midlatitude jets, their time evolution, and the upscale impacts on them. We present sample analyses from a one-year simulation using the 3.5 km mesh Nonhydrostatic Icosahedral Atmospheric Model (NICAM), revealing the realistic zonal contrast of tropical precipitation, no double ITCZ structure, the reasonable midlatitude jet position and intensity but a weak bias of storm track activities, and a warm bias over the Eurasia during boreal winter. We also clarify the cross-scale interaction, such as the effects of cold pools on mean precipitation over the Maritime Continent through the precipitation diurnal cycle and the effects of resolved gravity waves on midlatitude mean flows. The proposed one-year simulation protocol is referred to as the “Sendai Protocol.” This protocol is not unique or definite for evaluating GSRMs; we prospect a hierarchical set of experiments from short-term to multi-year simulations as GSRM intercomparisons.
How Can We Improve the Seamless Representation of Climatological Statistics and Weather Toward Reliable Global K‐Scale Climate Simulations? 査読有り

Daisuke Takasuka, Chihiro Kodama, Tamaki Suematsu, Tomoki Ohno, Yohei Yamada, Tatsuya Seiki, Hisashi Yashiro, Masuo Nakano, Hiroaki Miura, Akira T. Noda, Tomoe Nasuno, Tomoki Miyakawa, Ryusuke Masunaga

Journal of Advances in Modeling Earth Systems　2024年2月

DOI： 10.1029/2023MS003701 　
Parallelized Remapping Algorithms for km-scale Global Weather and Climate Simulations with Icosahedral Grid System 査読有り

Chihiro Kodama, Hisashi Yashiro, Takashi Arakawa, Daisuke Takasuka, Shuhei Matsugishi, Hirofumi Tomita

Proceedings of the International Conference on High Performance Computing in Asia-Pacific Region　2024年1月18日
出版者・発行元： ACM
DOI： 10.1145/3635035.3635040 　
Asymptotic Matching between Weather and Climate Models 査読有り

Hiroaki Miura, Tamaki Suematsu, Yuta Kawai, Yoko Yamagami, Daisuke Takasuka, Yuki Takano, Ching-Shu Hung, Kazuya Yamazaki, Chihiro Kodama, Yoshiyuki Kajikawa, Yukio Masumoto

Bulletin of the American Meteorological Society　104　(12)　E2308-E2315　2023年12月
出版者・発行元： American Meteorological Society
DOI： 10.1175/bams-d-22-0128.1 　

ISSN：0003-0007

eISSN：1520-0477

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Abstract The Deep Numerical Analysis for Climate (DNA-Climate) is a pilot project to develop an Earth system model on a kilometer-scale horizontal mesh. The acronym “DNA” is based on the analogies between the hierarchical structures of atmospheric phenomena and living organisms. The multiscale structure of clouds and circulations may be analogous to the multiscale structure of cells and organs organized according to the blueprint, deoxyribonucleic acid (DNA). Whereas global cloud-resolving models (CRMs) can produce better solutions on shorter time scales that are decisively governed by the initial conditions, global climate models (GCMs) may generate reliable solutions on longer time scales that are largely determined to balance energy inputs and outputs. Our challenge is to build a physically valid model that consistently bridges the shorter- and longer-time-scale solutions in the intermediate time scales. Research topics of DNA-Climate are configured in consideration of the structural similarity between the climate modeling and the technique of matched asymptotic expansions in mathematics. The central question is whether a single modeling framework using only either global CRM or GCM will work adequately at all time scales of climate, or whether a multiscale modeling framework combining several models, of which each is only valid for limited time scales, will be needed. A multiscale modeling is an attractive framework for advancing climate modeling and would be an intriguing topic to be studied in parallel with global CRMs and GCMs.
CERESMIP: a climate modeling protocol to investigate recent trends in the Earth's Energy Imbalance 査読有り

Gavin A. Schmidt, Timothy Andrews, Susanne E. Bauer, Paul J. Durack, Norman G. Loeb, V. Ramaswamy, Nathan P. Arnold, Michael G. Bosilovich, Jason Cole, Larry W. Horowitz, Gregory C. Johnson, John M. Lyman, Brian Medeiros, Takuro Michibata, Dirk Olonscheck, David Paynter, Shiv Priyam Raghuraman, Michael Schulz, Daisuke Takasuka, Vijay Tallapragada, Patrick C. Taylor, Tilo Ziehn

Frontiers in Climate　5　2023年7月3日
出版者・発行元： Frontiers Media SA
DOI： 10.3389/fclim.2023.1202161 　

eISSN：2624-9553

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The Clouds and the Earth's Radiant Energy System (CERES) project has now produced over two decades of observed data on the Earth's Energy Imbalance (EEI) and has revealed substantive trends in both the reflected shortwave and outgoing longwave top-of-atmosphere radiation components. Available climate model simulations suggest that these trends are incompatible with purely internal variability, but that the full magnitude and breakdown of the trends are outside of the model ranges. Unfortunately, the Coupled Model Intercomparison Project (Phase 6) (CMIP6) protocol only uses observed forcings to 2014 (and Shared Socioeconomic Pathways (SSP) projections thereafter), and furthermore, many of the ‘observed' drivers have been updated substantially since the CMIP6 inputs were defined. Most notably, the sea surface temperature (SST) estimates have been revised and now show up to 50% greater trends since 1979, particularly in the southern hemisphere. Additionally, estimates of short-lived aerosol and gas-phase emissions have been substantially updated. These revisions will likely have material impacts on the model-simulated EEI. We therefore propose a new, relatively low-cost, model intercomparison, CERESMIP, that would target the CERES period (2000-present), with updated forcings to at least the end of 2021. The focus will be on atmosphere-only simulations, using updated SST, forcings and emissions from 1990 to 2021. The key metrics of interest will be the EEI and atmospheric feedbacks, and so the analysis will benefit from output from satellite cloud observation simulators. The Tier 1 request would consist only of an ensemble of AMIP-style simulations, while the Tier 2 request would encompass uncertainties in the applied forcing, atmospheric composition, single and all-but-one forcing responses. We present some preliminary results and invite participation from a wide group of models.
Climate of High-obliquity Exoterrestrial Planets with a Three-dimensional Cloud System Resolving Climate Model 査読有り

Takanori Kodama, Daisuke Takasuka, Sam Sherriff-Tadano, Takeshi Kuroda, Tomoki Miyakawa, Ayako Abe-Ouchi, Masaki Satoh

The Astrophysical Journal　2022年11月1日

DOI： 10.3847/1538-4357/ac98ae 　
Deceleration of Madden-Julian Oscillation Speed in NICAM AMIP-type Simulation Associated with Biases in the Walker Circulation Strength 査読有り

Tamaki Suematsu, Hiroaki Miura, Chihiro Kodama, Daisuke Takasuka

Geophysical Research Letters　49　(11)　2022年3月16日
出版者・発行元： American Geophysical Union ({AGU})
DOI： 10.1002/essoar.10510854.1 　

ISSN：0094-8276 1944-8007
MJO Initiation Triggered by Amplification of Upper-tropospheric Dry Mixed Rossby-gravity Waves 査読有り

Daisuke Takasuka, Tsubasa Kohyama, Hiroaki Miura, Tamaki Suematsu

Geophysical Research Letters　48　(20)　2021年5月11日
出版者・発行元： American Geophysical Union ({AGU})
DOI： 10.1002/essoar.10507006.1 　

ISSN：0094-8276 1944-8007
Diversity of the Madden–Julian Oscillation: Initiation Region Modulated by the Interaction Between the Intraseasonal and Interannual Variabilities 査読有り

Daisuke Takasuka, Masaki Satoh

Journal of Climate　1-65　2021年2月1日
出版者・発行元： American Meteorological Society
DOI： 10.1175/jcli-d-20-0688.1 　

ISSN：0894-8755
A Wall-like Sharp Downward Branch of the Walker Circulation above the Western Indian Ocean 査読有り

Tsubasa Kohyama, Tamaki Suematsu, Hiroaki Miura, Daisuke Takasuka

Journal of Geophysical Research: Atmospheres　126　(21)　2021年1月27日
出版者・発行元： American Geophysical Union ({AGU})
DOI： 10.1002/essoar.10505995.1 　

ISSN：2169-897X 2169-8996
Dynamical Roles of Mixed Rossby–Gravity Waves in Driving Convective Initiation and Propagation of the Madden–Julian Oscillation: General Views 査読有り

Daisuke Takasuka, Masaki Satoh

Journal of the Atmospheric Sciences　1-63　2020年10月1日
出版者・発行元： American Meteorological Society
DOI： 10.1175/jas-d-20-0050.1 　

ISSN：0022-4928 1520-0469

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<jats:title>Abstract</jats:title> <jats:p>Motivated by the previous case study, this work shows that dynamical variations of mixed Rossby–gravity waves with tropical depression-type circulations (MRGTDs) are one possible drivers of convective initiation and propagation of the Madden–Julian oscillation (MJO) by performing statistical analysis. MJO events initiated in the Indian Ocean (IO) in boreal winter are objectively identified solely using outgoing longwave radiation data. The lagged-composite analysis of detected MJO events demonstrates that MJO convection is initiated in the southwestern IO (SWIO), where strong MRGTD–convection coupling is statistically found. Further classification of MJO cases in terms of intraseasonal convection and MRGTD activities in the SWIO suggests that 26 of 47 cases are related to more enhanced MRGTDs, although they can also be secondarily affected by Kelvin waves. For those MRGTD-enhanced MJO events, MJO convective initiation is primarily triggered by low-level MRGTD circulations which develop via the enhancement of downward energy dispersion in accordance with upper-tropospheric baroclinic conversion. This is supported by the modulation of MRGTD structure associated with zonal wave contraction due to upper-tropospheric zonal convergence, and plentiful moisture advected into the western IO. Following this MRGTD-induced MJO triggering and mid-tropospheric pre-moistening in the IO contributed by MRGTD shallow circulations as well as intraseasonal winds during the MJO-suppressed phase, low-level MRGTD winds with eastward group velocity successively trigger convection to the east, which helps MJO convective propagation over the IO. The interannual atmospheric variability may affect whether the presented MRGTD-related processes are effective or not.</jats:p>
Observational Evidence of Mixed Rossby‐Gravity Waves as a Driving Force for the MJO Convective Initiation and Propagation 査読有り

Daisuke Takasuka, Masaki Satoh, Satoru Yokoi

Geophysical Research Letters　2019年5月28日

DOI： 10.1029/2019GL083108 　

ISSN：0094-8276 1944-8007
Initiation Processes of the Tropical Intraseasonal Variability Simulated in an Aqua-Planet Experiment: What is the Intrinsic Mechanism for MJO Onset? 査読有り

Daisuke Takasuka, Masaki Satoh, Tomoki Miyakawa, Hiroaki Miura

Journal of Advances in Modeling Earth Systems　10　(4)　1047-1073　2018年4月
出版者・発行元： American Geophysical Union ({AGU})
DOI： 10.1002/2017ms001243 　

ISSN：1942-2466
Topographical Effects on Internally Produced MJO-Like Disturbances in an Aqua-Planet Version of NICAM 査読有り

Daisuke Takasuka, Tomoki Miyakawa, Masaki Satoh, Hiroaki Miura

SOLA　11　170-176　2015年
出版者・発行元： Meteorological Society of Japan
DOI： 10.2151/sola.2015-038 　

ISSN：1349-6476

︎全件表示 ︎最初の5件までを表示

MISC 1

全球雲解像モデルを用いたトラピスト1eの気候

小玉貴則, 高須賀大輔, 樋口太郎, 黒田剛史

日本惑星科学会秋季講演会予稿集(Web)　2024　2024年

講演・口頭発表等 13

Mixed Rossby-Gravity Waves as a Robust Precursor to MJO Initiation and Their Extratropical Linkages

Daisuke Takasuka, Hiroaki Miura

JpGU-AGU Joint Meeting 2026　2026年5月26日
ENSO and QBO Controls the Favorableness of the MJO Realization Cooperatively 招待有り

Dasiuke Takasuka, Tsubasa Kohyama, Tamaki Sueamtsu, Hiroaki Miura

JpGU-AGU Joint Meeting 2026　2026年5月24日
Deterministic chaotic behavior in the propagation of the Madden-Julian oscillation

Daisuke Takasuka, Tamaki Suematsu, Hiroaki Miura, Masuo Nakano

EGU General Assembly 2026　2026年5月6日
Relevance of Global km-scale Modeling for Large-scale Atmospheric Variability: Perspectives from a 10-year NICAM simulation 招待有り

Daisuke Takasuka

CMIP Community Workshop 2026　2026年3月11日
Relevance of Global km-scale Modeling for Large-scale Atmospheric Variability: Perspectives from a 10-year NICAM simulation

Daisuke Takasuka, Chihiro Kodama, Masuo Nakano, Yohei Yamada, Ryusuke Masunaga, Tamaki Suematsu, Hiroaki Miura

AGU Fall Meeting 2025　2025年12月18日
What do we see in the kilometer-scale climate modeling with NICAM?

Daisuke Takasuka

7th International Workshop on Nonhydrostatic Numerical Models　2025年11月18日
熱帯域の湿潤対流に対する波動・渦擾乱の役割：MJOを例に招待有り

高須賀大輔

日本気象学会2025年度秋季大会　2025年11月6日
全球雲解像モデルが紐解くMJOの決定論的カオス性招待有り

高須賀大輔

大槌シンポジウム2025：様々な時空間スケールの⼤気現象における普遍性と多様性　2025年8月8日
Multi-year climate simulations with km-scale NICAM: Strategies, Successes, and Outooks 招待有り

Daisuke Takasuka

WCRP Lighthouse Activities: Digital Earths webinar series　2024年1月16日
The Madden-Julian Oscillation and Associated Cross-scale Interaction Represented in a Kilometer-scale Atmospheric Climate Simulation 招待有り

Daisuke Takasuka

AGU Fall Meeting 2023　2023年12月13日
Tackling Errors Toward Realistic Seamless Representation in Kilometer-scale Climate Simulations With NICAM 招待有り

Daisuke Takasuka

IUGG General Assembly 2023　2023年7月15日
Recent Progress and Challenges on Global sub-5km mesh Model Experiments from the Sub-seasonal to Climate Scales 招待有り

Daisuke Takasuka

6th WGNE workshop on systematic errors in weather and climate models　2022年11月3日
Progress and challenges on high resolution Atmospheric modelling with NICAM 招待有り

Daisuke Takasuka

Workshop on Modeling the Climate System at Ultra-High-Resolution　2022年10月3日

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 5

全球雲解像気候モデルと最新の観測で開拓するグローバル極端気象学

小玉知央, 高須賀大輔, 梶川義幸, 末松環, 吉田龍二, 横井覚, 中野満寿男, 升永竜介

2026年4月1日～ 2030年3月31日
階層間相互作用から再考するMJOの発生・東進機構とその予測可能性

高須賀大輔

2026年4月～ 2029年3月
全球雲解像気候モデリングに基づく極端降水の温暖化応答とその階層構造の解明

高須賀大輔

提供機関：Japan Society for the Promotion of Science

制度名：Grants-in-Aid for Scientific Research

研究種目：Grant-in-Aid for Research Activity Start-up

研究機関：Tohoku University

2024年7月31日～ 2026年3月31日
マッデン・ジュリアン振動の発生における経年的な間欠性とその環境要因の解明

高須賀大輔

2020年4月～ 2021年3月

詳細を見る詳細を閉じる

マッデン・ジュリアン振動 (MJO) の顕在化頻度が経年的に変動する要因を解明するにあたり、本年度は主に観測に基づく40年分の再解析データを用いて、MJOよりも長い時間スケールで変動する海面水温分布や大気循環の影響に着目した統計解析を行った。インド洋・海洋大陸・西太平洋で顕在化するMJO事例をその活動が活発な期間とともに同定し、MJOが特に顕著に観測される北半球冬季 (11月-4月) に対してMJOの顕在化頻度を定量化した上で、その経年変動を特徴付ける場を調査した。その結果、MJOが顕在化しやすい年には、MJOよりも長い時間スケールでの対流活動がインド洋・西/中央太平洋 (海洋大陸) で有意に活発 (不活発) 傾向にあり、それに付随して背景場の東西循環は気候値よりも東西方向に伸展、南北循環は気候値が強化された傾向にあることを確認した。また、これらの場の実現には、成層圏準2年周期振動 (QBO) とエルニーニョ・南方振動 (ENSO) による協調的な強制が重要であることもわかった。具体的には、MJOの顕在化は、大振幅を除くエルニーニョ年であればQBO位相とは無関係にエルニーニョ傾向が強い時ほど、ENSO中立／ラニーニャ年であればENSOの振幅とは無関係にQBOに伴う上空東風が強い時ほど促進されることを見出し、これらが上記の背景場と無矛盾であることを示した。加えて、MJOが顕在化しづらい年には、MJOが顕在化しても西太平洋での水蒸気蓄積が阻害されるために持続期間が短くなることも判明し、この事実も背景場と整合的である。さらに、本研究課題を遂行する上で、対流圏上層に捕捉された混合ロスビー重力波が背景場の東西循環との相互作用を通じて "湿潤過程を介さずに" MJOを顕在化させうることが新たに明らかとなった。その内容は投稿論文としてまとめられ、現在国際誌に投稿中である。
全球雲システム解像モデルを用いたＭＪＯの発現および東進の決定機構に関する研究

高須賀大輔

2017年4月26日～ 2020年3月31日

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前年度の時点で、観測に基づく再解析データの統計解析などから、MJOの発生領域の決定には「海面水温 (SST) 分布によって部分的に強制されるMJOよりも長い時間スケールでの背景循環場」が重要であることが示唆されていた。これを踏まえ、本年度はこの知見の物理的理解および頑健性の検証に焦点を当て、引き続き再解析データを解析しつつ、全球雲システム解像モデルNICAMを用いた長期間の数値実験とその結果の解析を行った。再解析データの解析から、1) MJOの発生領域によらず、その発生前には主に季節内の時間スケールでの東西循環に伴って水蒸気蓄積が促進しやすい場が形成されること、2) 東西循環が確立されやすい位置が背景循環場と連動して変調することがMJOの発生領域の決定に影響することの2点が仮説として得られた。2) に関連して、インド洋でMJOが頻繁に発生する北半球冬季の平均的な状態に比べて、海大陸域 (西太平洋) でのMJO発生時には、SSTの経年変動成分が東部太平洋型のエルニーニョ (中央太平洋型のエルニーニョかつインド洋南東部での双極的構造) を伴う傾向にあったことを踏まえ、そのSST分布を模したものをNICAMの境界条件に設定し、15年間の季節固定実験 (北半球冬季) を複数実施した。その結果、いずれの実験でもMJOは自発的によく再現され、各実験間でのMJOの経度方向の発生確率分布の違いは、観測と整合的かつ統計的に有意であった。これは上述の2点の仮説の双方を支持するものであり、MJO発生領域の多様性の要因を初めて提唱するに至った。本内容は博士論文の一部としてまとめられ、国際誌への投稿論文として間もなく投稿できる段階にある。前年度の主要な成果である「MJOと混合ロスビー重力波とのスケール間相互作用」については、その一般性を論じた論文を国際誌に投稿し、査読過程での改稿中である。