プラズマ球の振動による放射線帯の電子損失のグローバルスケールコヒーレンス変調
A W Breneman1, A Halford2, R Millan2
1School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Nature
|July 1, 2015
まとめ
地球の放射線帯における電子の喪失は,プラズマ球の鳴き声によって引き起こされる. この研究では,これらの損失を直接観察し,プラズマ密度と磁場変動に関連した急速で大きな変化を明らかにしました.
科学分野:
- 宇宙物理学 宇宙物理学
- プラズマ物理学 プラズマ物理学
- 地質物理学 地質物理学とは地質物理学です.
背景:
- 地球の放射線帯,特にプラズマ圏内の電子の損失は,長らくプラズマ圏との相互作用に起因していると考えられてきました.
- このプロセスは,地磁気嵐後の放射線帯構造の回復に不可欠です.
- 以前の観測では,長期の電子喪失率が確認されたが,時間的・空間的動態の直接的な検証はできなかった.
研究 の 目的:
- プラズマスフィアの上昇によって引き起こされる放射線帯における電子喪失の時間的・空間的動態を直接検証する.
- 電子喪失現象とプラズマ球の特性との関係を調査する.
- これらの損失ダイナミクスに対するプラズマ密度と磁場変調の影響を理解するために.
主な方法:
- 放射線帯の電子損失とプラズマ球の上昇を同時に測定する.
- 大気に衝撃を与える電子が散らばったため息によって生成されるブレームストラハリングX線の観測.
- プラズマ密度と磁場変動に関連した電子喪失の動態の分析.
主要な成果:
- プラズマスフィアの上昇に関連した構造化放射線帯の電子損失の直接観測.
- 電子喪失のダイナミクスは,短い時間スケール (1〜20分) で有意な変化 (数桁の大きさまで) を示した.
- 電子の損失とヒースの動態の間の地球規模に近い相関性が観察されましたが,これは予想外でした.
結論:
- この研究は,プラズマ圏のヒスを,放射線帯の急速で構造的な電子損失と結びつける直接的な証拠を提供します.
- プラズマ密度と磁場における急速な変調は,電子喪失のダイナミクスを著しく影響する.
- 失われたダイナミクスの発見された地球規模の一貫性は,活発な期間中の短期的な放射線帯の進化に影響を与える可能性があります.
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