| Project/Area Number |
01540350
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Space and upper atmospheric physics
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| Research Institution | Nagoya University |
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Principal Investigator |
OGINO Tatsuki Nagoya University. Solar-Terrestrial Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (00109274)
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| Co-Investigator(Kenkyū-buntansha) |
OKADA Toshimi Toyama Prefecture University, Department of Engineering, Associate Professor, 工学部, 助教授 (90008566)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1989: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Magneto Hydrodynamics / Earth's Magnetosphere / Computer Simulation / Magnetic Reconnection / Helical Plasmoid / Magnetic flux rope / Boundary Layer / Instability phenomena / 太陽風磁気圏相互作用 / 地球磁気圏ダイナミックス / 磁気圏境界層 |
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| Research Abstract |
For the first time. we carried out a global MHD simulation on the structure and dynamics of magnetotail depending on the orientation of the interplanetary magnetic field (IMF) in the plane of north-south, east-west. As a results, the magnetic neutral line forms in the plasma sheet for southward IMF and a hot plasma is ejected towards the tail. When there is a large east-west component of IMF during the southward interval of IMF, the magnetic field lines which confine hot plasma become a helical structure. Both edges of the helical plasmoid are gradually winded are concented to the earth's ionosphere as the helical plasmoid somewhat shifts towards the tail. Then a structure like magnetic flux rope, that confines a longitudinal magnetic field instead of plasma, appears between the ionosphere and the edges of the helical plasmoid. The tail reconnection proceeds in the whole plasma sheet region and the hot plasmoid is ejected tailward as a helical plasmoid when all the field lines are disconnected.
Moreover we carried out a high resolution MHD simulation in two times grid points by introducing a newly developed MHD code in a modified leap-frog method in order to study a boundary layer phenomena. The thickness of magnetopause is thinner for southward IMF and it is thicker for northward IMF. Thiis is because the magnetic field varies mildly across the magnetopause for northward, on the other hand a high pressure plasma appears in the dayside neutral line to make thinner the magnetopause. When time elapses, the boundary layer (or magnetopause) has a wavy structure for the shake of dayside magnetic merging. The wavy structure enlarges the momentum transfer from magnetosheath to magnetopause.
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