Challenge for convective conundrum with large-scale numerical simulations

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K14510
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: Chiba University
• Principal Investigator: Hotta Hideyuki 千葉大学, 大学院理学研究院, 准教授 (10767271)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: ダイナモ / 熱対流 / 乱流

Outline of Final Research Achievements

Although the solar internal structure has been well inferred from previous theory and observations, the resulting thermal convection and differential rotation are inconsistent with observations. This discrepancy was known as the 'convection conundrum.' In this study, large-scale simulations were used to challenge the 'convection conundrum,' and we succeeded in solving the differential rotation aspect. By carrying out calculations using Fugaku, it was revealed that the magnetic field is stronger in the solar interior than previously thought and that this field plays a major role in angular momentum transport.

Free Research Field

太陽物理学

Academic Significance and Societal Importance of the Research Achievements

太陽は活動的な恒星であり、その活動は磁場により維持されている。太陽の磁場活動を理解するためには、太陽内部の乱流構造を理解する必要があるが、これまでは観測と理論に大きな乖離があり、我々の理解を阻んでいた。今回の研究では、太陽内部を50億点以上で分解するような超大規模シミュレーションに挑戦し、その結果観測と理論の乖離を解決することができた。この成果により、今後、太陽活動の根元に迫るような研究が可能になるだろう。