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State Transition of the Solar Magnetic Field: Probing the Trigger for the Solar Activity Grand Minimum through MHD Simulations

Research Project

Project/Area Number 18K03700
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Review Section Basic Section 16010:Astronomy-related
Research InstitutionFukuoka University (2022-2023)
Aichi University of Education (2018-2021)

Principal Investigator

Yohei MASADA  福岡大学, 理学部, 准教授 (30590608)

Project Period (FY) 2018-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywordsプラズマ / 太陽・恒星 / 天体ダイナモ / 乱流 / 乱流輸送 / 熱対流 / トポロジカルデータ解析 / 機械学習 / 太陽 / 非平衡輸送 / ダイナモ / 深層学習 / 対流 / 中性子星 / 超新星爆発 / 不安定性 / 超新星 / 電磁流体 / 天体プラズマ / MHD
Outline of Final Research Achievements

The thermal convection, which is the origin of the solar magnetic field, is not fully understood even in terms of its driving mechanisms. There are two candidate driving mechanisms for solar thermal convection: cooling-driven (CD) and entropy gradient-driven (ED). The results of this study have revealed that (i) the CD type better reproduces the characteristic patterns of solar convection, (ii) in the CD type, non-linear and non-equilibrium downward plumes significantly contribute to the transport, and (iii) the presence of downward plumes causes a significant deviation from a Gaussian distribution in the frequency distribution of the convection (Yokoi et al. 22; Masada et al. 24 in prep.). Furthermore, the knowledge gained from this study has been applied to other astrophysical thermal convection phenomena, leading to several pioneering results.

Academic Significance and Societal Importance of the Research Achievements

太陽の内部熱対流は太陽磁場(黒点)の成因だと考えられており、本研究で得た成果は、太陽磁気活動に対する我々の理解の深化につながる。太陽磁気活動に対する理解が深まることで、地球の気候変動予測や宇宙天気予報の精度が向上し、通信や電力網の障害対策に寄与できる(社会的意義)。また、太陽は究極の高レイノルズ数・高磁気レイノルズ数・高レイリー数流体であり、地上の実験室では実現不可能なパラメータレンジでの熱対流のメカニズムに関する本研究の成果は、他の天体現象の背後にある物理の解明につながるだけでなく、流体力学やプラズマ物理学など基礎物理の分野にも大きなインパクトを与える(学術的意義)。

Report

(7 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (44 results)

All 2024 2023 2022 2021 2020 2019 2018 Other

All Int'l Joint Research (7 results) Journal Article (9 results) (of which Int'l Joint Research: 8 results,  Peer Reviewed: 7 results,  Open Access: 7 results) Presentation (25 results) (of which Int'l Joint Research: 11 results,  Invited: 9 results) Book (1 results) Remarks (2 results)

  • [Int'l Joint Research] Nordita(北欧理論物理学研究所)(スウェーデン)

    • Related Report
      2023 Annual Research Report
  • [Int'l Joint Research] Institute for Solar-Terrestrial Physics(ロシア連邦)

    • Related Report
      2023 Annual Research Report
  • [Int'l Joint Research] Leibniz-Institute for Astrophysics(ドイツ)

    • Related Report
      2023 Annual Research Report
  • [Int'l Joint Research] Nordita(スウェーデン)

    • Related Report
      2022 Research-status Report
  • [Int'l Joint Research] Max-Planck-Institute (MPS)(ドイツ)

    • Related Report
      2021 Research-status Report
  • [Int'l Joint Research] Newcastle University(英国)

    • Related Report
      2018 Research-status Report
  • [Int'l Joint Research] Nordita, Stockholm University(スウェーデン)

    • Related Report
      2018 Research-status Report
  • [Journal Article] Turbulent Processes and Mean-Field Dynamo2023

    • Author(s)
      Brandenburg Axel、Elstner Detlef、Masada Youhei、Pipin Valery
    • Journal Title

      Space Science Reviews

      Volume: 219 Issue: 7 Pages: 1-57

    • DOI

      10.1007/s11214-023-00999-3

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Turbulent processes and mean-field dynamo2023

    • Author(s)
      Brandenburg, Axel ; Elstner, Detlef ; Masada, Youhei ; Pipin, Valery
    • Journal Title

      arXiv:2303.12425 (submitted to Space Science Review)

      Volume: 2303.12425

    • Related Report
      2022 Research-status Report
    • Int'l Joint Research
  • [Journal Article] Modelling stellar convective transport with plumes: I. Non-equilibrium turbulence effect in double-averaging formulation2022

    • Author(s)
      Yokoi N、Masada Y、Takiwaki T
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: - Issue: 2 Pages: 2718-2735

    • DOI

      10.1093/mnras/stac1181

    • Related Report
      2022 Research-status Report 2021 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Rotational Dependence of Large-scale Dynamo in Strongly-stratified Convection: What Causes It?2022

    • Author(s)
      Masada, Youhei ; Sano, Takayoshi
    • Journal Title

      ArXiv.2206.06566 (submitted to ApJ)

      Volume: 2206.06566

    • Related Report
      2022 Research-status Report
  • [Journal Article] Multi-scale deep learning for estimating horizontal velocity fields on the solar surface2022

    • Author(s)
      Ishikawa Ryohtaroh T.、Nakata Motoki、Katsukawa Yukio、Masada Youhei、Riethmuller Tino L.
    • Journal Title

      Astronomy & Astrophysics

      Volume: 658 Pages: A142-A142

    • DOI

      10.1051/0004-6361/202141743

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Neutrino-dominated Accretion Flows with Magnetic Prandtl Number-dependent MRI-driven Turbulence2019

    • Author(s)
      Norita Kawanaka; Youhei Masada
    • Journal Title

      The Astrophysical Journal

      Volume: 881 Issue: 2 Pages: 138-138

    • DOI

      10.3847/1538-4357/ab2e71

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Propagation, cocoon formation, and resultant destabilization of relativistic jets2019

    • Author(s)
      Jin Matsumoto; Youhei Masada
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 490 Issue: 3 Pages: 4271-4280

    • DOI

      10.1093/mnras/stz2821

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Large-scale dynamos in rapidly rotating plane layer convection2018

    • Author(s)
      Bushby P. J.、Kapyla P. J.、Masada Y.、Brandenburg A.、Favier B.、Guervilly C.、Kapyla M. J.
    • Journal Title

      Astronomy & Astrophysics

      Volume: 612 Pages: A97-A97

    • DOI

      10.1051/0004-6361/201732066

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Chiral magnetohydrodynamic turbulence in core-collapse supernovae2018

    • Author(s)
      Masada Youhei、Kotake Kei、Takiwaki Tomoya、Yamamoto Naoki
    • Journal Title

      Physical Review D

      Volume: 98 Issue: 8 Pages: 083018-083018

    • DOI

      10.1103/physrevd.98.083018

    • Related Report
      2018 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Presentation] 機械学習による天体内部熱対流モデルの検討2024

    • Author(s)
      政田洋平、本武陽一,仲田資季
    • Organizer
      日本天文学会春季年会2024
    • Related Report
      2023 Annual Research Report
  • [Presentation] 太陽熱対流は局所駆動か?冷却駆動か?2024

    • Author(s)
      政田洋平、本武陽一,仲田資季
    • Organizer
      統数研共同研究集会 兼 第4回TREFOIL研究会:高次元非線形構造が紡ぎ出す数理・情報・物理の融合研究
    • Related Report
      2023 Annual Research Report
  • [Presentation] 天体プラズマ: 極限的な乱流状態における構造形成2023

    • Author(s)
      政田洋平
    • Organizer
      第1回プラズマ・核融合夏の学校 2023
    • Related Report
      2023 Annual Research Report
    • Invited
  • [Presentation] 太陽粒状斑の統計的性質とその活動サイクル依存性- 衛星ビッグデータの画像処理による解析 -2023

    • Author(s)
      政田洋平,Bohla Panta
    • Organizer
      第3回TREFOIL研究会
    • Related Report
      2023 Annual Research Report
  • [Presentation] Modeling Convection and Transport in the Sun2023

    • Author(s)
      Youhei MASADA
    • Organizer
      IAU Symposium 365 “Dynamics of Solar and Stellar Convection Zones and Atmospheres (Yerevan, Armenia)
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Modeling Convection and Transport in the Sun2023

    • Author(s)
      Youhei MASADA
    • Organizer
      AAPPS-DPP 2023
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Solar and Stellar Dynamos : the linkage between MHD simulations and MF models2022

    • Author(s)
      Masada, Y.
    • Organizer
      ISSI workshop - Solar and Stellar Dynamos: A New Era -
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Magnetohydrodynamics with Swirling Flow : Spontaneous Order - From the Sun to Compact Objects -2022

    • Author(s)
      Masada, Y.
    • Organizer
      Plasma Explosions in the Universe (PEU2022)
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research
  • [Presentation] 太陽磁気活動の球殻平均場モデルの開発2022

    • Author(s)
      政田洋平、松本仁
    • Organizer
      第35回理論懇シンポジウム 「理論天文学・宇宙物理学の広がり :さらなる発展に向けて」
    • Related Report
      2022 Research-status Report
  • [Presentation] Spherical-shell Mean-field Solar Dynamo model based on a EMF extracted from DNS of Turbulent Convection2022

    • Author(s)
      Masada, Y.
    • Organizer
      RIMS Satellite Seminar : Mathematical modeling of turbulent flows in astrophysical and geophysical phenomena
    • Related Report
      2022 Research-status Report
    • Int'l Joint Research
  • [Presentation] Solar/stellar dynamo: connection between MHD simulations and mean-field models2022

    • Author(s)
      Youhei Masada
    • Organizer
      ISSI workshop "Solar and Stellar Dynamos: A new Era"
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Convection and Dynamo in Newly-born Neutron Stars2021

    • Author(s)
      Youhei Masada; Tomoya Takiwaki; Kei Kotake
    • Organizer
      OCAMI研究集会:ヘリシティと時空対称性、古典場から量子場まで
    • Related Report
      2021 Research-status Report
    • Int'l Joint Research
  • [Presentation] 太陽熱対流の非局所性とその輸送ダイナミクスへの影響 :理論モデルの検討2020

    • Author(s)
      政田洋平、滝脇知也、横井喜充
    • Organizer
      第37回 プラズマ・核融合学会年会
    • Related Report
      2020 Research-status Report
  • [Presentation] 強密度成層下の乱流起電力を考慮した球殻平均場太陽ダイナモモデル2020

    • Author(s)
      政田洋平, 松本仁
    • Organizer
      日本天文学会 2020 春季年会
    • Related Report
      2019 Research-status Report
  • [Presentation] Mean-field Modeling of Large-scale Dynamo in Solar-like Strongly-stratified Convection - the Rossby number Dependence -2019

    • Author(s)
      Youhei Masada
    • Organizer
      Space Climate 7 - The Future of Solar Activity-
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] Spontaneous Formation of Large-scale Flow and Magnetic Fields in Proto-Neutron Stars2019

    • Author(s)
      Youhei Masada
    • Organizer
      Multi-dimensional Modeling and Multi-Messenger observation from Core-Collapse Supernovae (4M-COCOS)
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 太陽熱対流の非局所性:プルームとエントレインメント2019

    • Author(s)
      政田洋平
    • Organizer
      2019NINS 若手分野間連携プロジェクト キックオフ会合
    • Related Report
      2019 Research-status Report
  • [Presentation] 原始中性子星における対流ダイナモと大局的磁場形成2019

    • Author(s)
      政田洋平, 滝脇知也, 固武慶
    • Organizer
      日本天文学会 2019 秋季年会
    • Related Report
      2019 Research-status Report
  • [Presentation] 原始中性子星における乱流・輸送・自発的構造形成2019

    • Author(s)
      政田洋平, 滝脇知也, 固武慶, 仲田資季
    • Organizer
      プラズマ核融合学会第 36 回年会
    • Related Report
      2019 Research-status Report
  • [Presentation] The Evolution of Rotating and Magnetized Stars2019

    • Author(s)
      Youhei MASADA
    • Organizer
      DoS workshop
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 太陽熱対流の非局所性とその輸送ダイナミクスへの影響2019

    • Author(s)
      政田洋平
    • Organizer
      日本天文学会2019春季年会
    • Related Report
      2018 Research-status Report
  • [Presentation] 星の内部熱対流:その理解の太陽での検証と超新星への応用2019

    • Author(s)
      政田洋平
    • Organizer
      CfCA User’s Meeting 2018
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] Evolution of the Solar/Steller magnetism2019

    • Author(s)
      Youhei MASADA
    • Organizer
      International workshop on relations between solar evolution and atmospheric escape from terrestrial planets
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] 太陽内部熱対流の非局所性に関する考察2018

    • Author(s)
      政田洋平
    • Organizer
      プラズマ核融合学会第35回年会
    • Related Report
      2018 Research-status Report
  • [Presentation] Numerical simulations of solar magnetism: Organization of large-scale magnetic structure in turbulent stratified convection2018

    • Author(s)
      Youhei MASADA
    • Organizer
      12th International Conference on High Energy Density Laboratory Astrophysics (HEDLA)
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Book] 極・宇宙を解く 現代天文学演習2020

    • Author(s)
      編:福江純, 沢武文, 高橋真聡 (政田は執筆者の一人として参加)
    • Total Pages
      308
    • Publisher
      恒星社恒星閣
    • ISBN
      9784769916437
    • Related Report
      2019 Research-status Report
  • [Remarks] Plasma Astrophysics Laboratory プラズマ天体物理研究室(政田研)

    • URL

      https://www.phyas.aichi-edu.ac.jp/~ymasada/

    • Related Report
      2019 Research-status Report
  • [Remarks] プラズマ天体物理研究室(政田研)

    • URL

      http://www.phyas.aichi-edu.ac.jp/~ymasada/

    • Related Report
      2018 Research-status Report

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Published: 2018-04-23   Modified: 2025-01-30  

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