Item type |
itemtype_ver1(1) |
公開日 |
2022-02-08 |
タイトル |
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タイトル |
Field-Aligned Low-Energy O^+ Flux Enhancements in the Inner Magnetosphere Observed by Arase |
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言語 |
en |
著者 |
Nosé, M.
Matsuoka, A.
Miyoshi, Y.
Asamura, K.
Hori, T.
Teramoto, M.
Shinohara, I.
Hirahara, M.
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アクセス権 |
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アクセス権 |
open access |
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アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
権利 |
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言語 |
en |
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権利情報 |
© 2021 American Geophysical Union |
内容記述 |
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内容記述 |
The present study examines the low-energy ion flux variations observed by the Arase satellite in the inner magnetosphere. From the magnetic field and ion flux data obtained by the fluxgate magnetometer and the low-energy particle experiments–ion mass analyzer onboard Arase, we find 55 events of the low-energy O^+ flux enhancement accompanied with magnetic field dipolarization in the periods of April 1–October 31, 2017 and July 1, 2018–January 31, 2019. The low-energy O^+ flux enhancements (a) start a few minutes after the dipolarization onset, (b) have energy-dispersed signatures with decreasing energy from a few keV down to ∼10 eV, (c) are observed in both storm and non-storm periods, (d) have a field-aligned distribution (α ∼ 0° in the southern hemisphere and α ∼ 180° in the northern hemisphere), (e) are accompanied by the low-energy H^+ flux enhancements that have lower energies than O^+ by a factor of 3–10, and (f) increase the O^+ density and the O^+/H^+ density ratio by ∼10 times and 4–5 times, respectively. We perform a numerical simulation to trace ion trajectories forward in time from the Arase positions. It is revealed that both H^+ and O^+ ions drift eastward and reach the dawn-to-morning sector without being lost in the ionosphere, if the pitch angle scattering effect is considered near the equatorial plane. This result suggests that these low-energy field-aligned ions can contribute to formation of the warm plasma cloak. |
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言語 |
en |
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内容記述タイプ |
Abstract |
出版者 |
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言語 |
en |
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出版者 |
Wiley |
言語 |
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言語 |
eng |
資源タイプ |
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資源タイプresource |
http://purl.org/coar/resource_type/c_6501 |
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タイプ |
journal article |
出版タイプ |
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出版タイプ |
VoR |
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出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
関連情報 |
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関連タイプ |
isVersionOf |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.1029/2021JA029168 |
収録物識別子 |
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収録物識別子タイプ |
EISSN |
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収録物識別子 |
2169-9402 |
書誌情報 |
en : Journal of Geophysical Research-Space Physics
巻 126,
号 8,
p. e2021JA029168,
発行日 2021-08
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