Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
1986-08-01 |
タイトル |
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言語 |
en |
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タイトル |
Characteristics of small-scale magnetic fluctuations over the high-latitude ionosphere |
言語 |
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言語 |
eng |
資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
departmental bulletin paper |
ページ属性 |
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内容記述タイプ |
Other |
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内容記述 |
P(論文) |
著者名(英) |
Iyemori, Toshihiko
Ikeda, Tatsuya
Nakagawa, Akinari
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著者所属(英) |
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en |
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Data Analysis Center for Geomagnetism and Spacemagnetism, Faculty of Science, Kyoto University |
著者所属(英) |
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en |
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Data Analysis Center for Geomagnetism and Spacemagnetism, Faculty of Science, Kyoto University |
著者所属(英) |
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en |
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Data Analysis Center for Geomagnetism and Spacemagnetism, Faculty of Science, Kyoto University |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
The global amplitude distributions of the small-scale (1<L<35km) or short-time scale (0.12<T<5s) magnetic fluctuations over the high-latitude ionosphere are obtained for various geomagnetic, seasonal and IMF conditions using the MAGSAT data and are compared with the large-scale Birkeland currents. On the dayside, the maximum of the amplitude distribution appears near the poleward edge of the large-scale Birkeland current region-1 or at the latitude poleward of it. The amplitude strongly depends on the ionospheric conductivity and varies about factor three or more even in the same conditions of the geomagnetic activity, suggesting that the fluctuations are generated mainly by small-scale Birkeland currents rather than by Alfven waves. The IMF-By causes the dawn-dusk asymmetry of the amplitude and the IMF-Bz controls the latitudinal distribution of the fluctuations. On the night-side, the amplitude is controlled mainly by the geomagnetic activity, and the active region statistically corresponds to the large scale Birkeland current regions. However, the correlation between the amplitude and the large-scale Birkeland current density is not necessarily good. On both sides, the latitude of the maximum amplitude roughly correspond to that of the large-scale magnetospheric convection reversal, suggesting that the small-scale Birkeland currents originate from the turbulence generated in the strong convection shear regions. |
雑誌書誌ID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA00733561 |
書誌情報 |
Memoirs of National Institute of Polar Research. Special issue
巻 42,
p. 92-102,
発行日 1986-08
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