Study of non-stational dynamical processes in solar chromosphere and coronal heating

• Project/Area Number: 18540235
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Astronomy
• Research Institution: University of Toyama
• Principal Investigator: 坂井 純一 University of Toyama, 大学院・理工学研究部, 教授 (50019220)
• Project Period (FY): 2006 – 2009
• Project Status: Completed (Fiscal Year 2008)
• Budget Amount: ¥4,070,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥570,000); Fiscal Year 2008: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
• Keywords: 太陽プラズマ / コロナ加熱 / シミュレーション / 太陽彩層 / 磁気再結合 / 磁気再結

Research Abstract

イオンー中性水素の2流体シミュレーションコードを開発(TwoYama)し、電離過程、再結合過程、イオンー中性水素衝突過程、熱伝導過程、磁気再結合過程を取り入れた。
TwoYamaコードを用いて、太陽彩層での電流ループの合体現象が調べられた。2つの電流ループが合体するとき磁気再結合が発生するが、これまでのMHD 近似で得られた結果とかなり異なる結果が得られ、太陽彩層ではMHD 近似が不適当であることが明らかになった。Hinode太陽観測衛星によって観測されたPenumbra Microjets の発生機構のモデルをTwoYama コードを用いたシミュレーション結果をもとに提案した。太陽光球面近傍の対流運動からAlfven波が自発的に発生し彩層上部を加熱することを示した。このAlfven 波によって運ばれるエネルギーがコロナ加熱に必要なエネルギーとして十分あることが定量的に確認された。

Research Products

• [Journal Article] Modeling penumbral micro-jets by two-fluid simulations (2009)
  • Author(s): J.I. Sakai and P.D. Smith
  • Journal Title: The Astrophysical Journal (Letters) (2008) 687 Pages: 127-130
• [Journal Article] Two-fluid simulations of coalescing penumbra filaments driven by neutral-hydrogen flows (2009)
  • Author(s): J.I. Sakai and P.D. Smith
  • Journal Title: The Astrophysical Journal (Letters) 691 Pages: 45-48
• [Journal Article] Two-fluid simulations of coalescing penumbra filaments driven by neutral-hydrogen flows (2009)
  • Author(s): J. I. Sakai, P. Smith
  • Journal Title: The Astrophysical Journal 691
  • Peer Reviewed
• [Journal Article] Chromospheric magnetic reconnection : Two-fluid simulations of coalescing current loops (2008)
  • Author(s): P.D. Smith and J.I. Sakai
  • Journal Title: Astronomy and Astrophysics 486 Pages: 569-575
• [Journal Article] Modeling penumbral micro-jets by two-fluid simulations (2008)
  • Author(s): J. I. Sakai, P. Smith
  • Journal Title: The Astrophysical Journal 687
  • Peer Reviewed
• [Journal Article] Particle-in-cell simulation of shocks and band splitting of TypeII bursts (2008)
  • Author(s): J. I. Sakai & M. Karlicky
  • Journal Title: Astronomy alld Astrophysics 478 Pages: 15-18
  • Peer Reviewed
• [Journal Article] On the effect of baryon loading in magnetized counterstreaming plasma (2008)
  • Author(s): R. C. Tautz & J. I. Sakai
  • Journal Title: Journal of Plasma Physics 74 Pages: 79-90
  • Peer Reviewed
• [Journal Article] Simulation of collision of two current loops in the upper chromosphere using two fluids model (2006)
  • Author(s): J.I. Sakai, K. Tsuchimoto, and I.V. Sokolov
  • Journal Title: The Astrophysical Journal 642 Pages: 1236-1245
• [Journal Article] Simulation of collision of two current loops in the upper chromosphere using two fluids model (2006)
  • Author(s): J.I.Sakai, K.Tsuchimoto, I.Sokolov
  • Journal Title: The Astrophysical Journal 642 Pages: 1236-1245
• [Journal Article] Electron heating by large amplitude shear Alfven waves in collisionless plasmas with force-free magnetic configuration : heating of upper chromosphere (2006)
  • Author(s): J.I.Sakai, S.Saito
  • Journal Title: Astronomy and Astrophysics 452 Pages: 597-601
• [Journal Article] A triggering mechanism of magnetic reconnection and particle acceleration during thinning of current sheet (2006)
  • Author(s): S.Saito, J.I.Sakai
  • Journal Title: The Astrophysical Journal 652 Pages: 793-799
• [Journal Article] Two-fluid simulations of chromospheric heating by Alfven waves
  • Author(s): J.I. Sakai and P.D. Smith
  • Journal Title: Astronomy and Astrophysics (2009) submitted
• [Presentation] Two-fluid simulations of coalescing penumbra filaments driven by neutral-hydrogen flows (2008)
  • Author(s): J.I. Sakai and P.D. Smith
  • Organizer: Second Hinode Science Meeting, Beyond discovery-toward understanding
  • Place of Presentation: Boulder, Colorado, USA