Study on long-term variation of solar global environment associated with solar cycle activity

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K14401
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Space and upper atmospheric physics
• Research Institution: Nagoya University
• Principal Investigator: Imada Shinsuke 名古屋大学, 宇宙地球環境研究所, 講師 (40547965)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 太陽 / 地球環境 / 長期変動 / 太陽風

Outline of Final Research Achievements

Focusing on one solar cycle from 2010 to the present, the open magnetic field lines are detected by combination of the surface flux transport model and the magnetic field line tracking technique. The position of the corona hole and the solar wind sources are estimated and their temporal changes are discussed. Magnetic field lines were traced from the sun surface using the PFSS (Potential Field Source Surface) extrapolation method from the calculated magnetic field of the whole sun obtained by the surface flux transport model. Long-term fluctuations of the solar terrestrial environment were considered by applying a solar wind model by using the present global magnetic field data as initial values and probabilistically giving sunspots for the next 10 years to carry out a large amount of solar surface magnetic flux transport calculations.

Free Research Field

太陽物理学

Academic Significance and Societal Importance of the Research Achievements

これまで宇宙天気研究は長いタイムスケールの現象の予測はそれほど行われて来なかった。そこで本研究では、今後10年間に出現する黒点を確率的に与え、大量の太陽表面磁束輸送計算をおこなうことで、今後10年の太陽表面磁場を確立的に求めた。さらに得られた太陽表面磁場に太陽風モデルを適応することで、今後10年の太陽風の長期変動を予測し、太陽地球環境の長期変動を考察した。