2002 Fiscal Year Final Research Report Summary
Studies on magnetospheric boundary processes based on magnetic field and aurora observation in the northern and southern polar caps
| Project/Area Number |
12573007
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Space and upper atmospheric physics
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| Research Institution | Tohoku University |
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Principal Investigator |
FUKUNISHI Hiroshi Graduate School of Science, Professor, 大学院・理学研究科, 教授 (90099937)
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| Co-Investigator(Kenkyū-buntansha) |
SAKANOI Takeshi Graduate School of Science, Research Associate, 大学院・理学研究科, 助手 (80271857)
TAKAHASHI Yukihiro Graduate School of Science, Lecturer, 大学院・理学研究科, 講師 (50236329)
OKANO Shoichi Graduate School of Science, Professor, 大学院・理学研究科, 教授 (10004483)
TAGUCHI Makoto National Institute of Polar Research, Associate Professor, 助教授 (70236404)
YAMAGISHI Hisao National Institute of Polar Research, Associate Professor, 助教授 (20132714)
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| Project Period (FY) |
2000 – 2002
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| Keywords | AGO / magnetospheric boundary / magnetic field / magetic pulsation / impuls / MIE / Solar wind / discontinuity |
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| Research Abstract |
In order to clarify the interaction between the solar wind and the magnetosphere of the Earth, magnetospheric boundary processes were investigated, making use of 6 non-manned automatic geophysical observatories (AGO) located in the interior of the Antarctic Continent. Comprehensive analysis was carried out, combining data recorded by AGO equipments, such as magnetometers, aurora imagers, riometers and VLF receivers, and solar wind and solar activity data obtained by spacecrafts as well as HF radar data at Syowa station. Results including some important and new findings are as follows:
1) Conjugate TCV (traveling convection vortices) events moving sunward in both hemispheres were found and its physical mechanisms were investigated in detail.
2) Transient ionospheric disturbances relating to the TCV were found. It is shown that the disturbances are consequence of non-linear processes in F-region caused by 3-D current system and auroral particle precipitations.
3) Automatic detection algorithms for MIE (magnetic impulse event) and for TD (tangential discontinuity) were developed successfully.Using these algorithms,it was found that occurences of MIE and TD show correlation in seasonal variation.
4) A tecchnique to calculate the TD arrival time using data obtained by one spacecraft was developed.
5) Quantitative model for TCV phenomena considering conjugate condition in the magnetosphere-ionosphere coupling processes was constructed.
6) 3-D MHD simulation was conducted to understand the current generation mechanisms associated with TCV. The results succeeded in reproducing typical TCV phenomena.
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