Heliospheric structure and cosmic ray modulation during grand minimum

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05671
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: National Institute of Polar Research
• Principal Investigator: Ryuho Kataoka 国立極地研究所, 研究教育系, 准教授 (90462671)
• Co-Investigator(Kenkyū-buntansha): 三宅 晶子 茨城工業高等専門学校, 国際創造工学科, 准教授 (00613027) ; 松本 倫明 法政大学, 人間環境学部, 教授 (60308004)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 銀河宇宙線 / 太陽圏 / グランドミニマム

Outline of Final Research Achievements

The purpose of this study is to elucidate the effect of peculiar solar wind activity and heliospheric structure on the modulation of the galactic cosmic ray spectrum that reaches the earth and its mechanism during extremely low solar activity such as grand minimum. The hybrid simulation, which combines the magnetohydrodynamic simulation of the solar wind and the stochastic differential equation simulation of cosmic rays, was a technical goal at the beginning of the research plan, but significant issues in each simulation became clear, and basic research has advanced.In addition, regarding the unexpected space weather event that occurred during the research period, the research results on the prediction of exposure dose at the International Space Station and aircraft were obtained.

Free Research Field

宇宙空間物理学

Academic Significance and Societal Importance of the Research Achievements

マウンダー極小期の定量的な物理解明には至っていない。しかしながら、研究期間中に発生した予想外の宇宙天気イベントに着目し、幾つかの応用科学的な研究成果が得られた。いずれも、今後の高度な宇宙利用に宇宙天気予報の発展に資するものとして、社会的な意義がある。