Sustaining Saturn's Electron Radiation Belts Through Episodic, Global-Scale Relativistic Electron Flux Enhancements
文献类型:期刊论文
作者 | Yuan, C. -J.2,3,4; Roussos, E.1; Wei, Y.2,3,4; Krupp, N.1 |
刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
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出版日期 | 2020-05-01 |
卷号 | 125期号:5页码:13 |
关键词 | Radiation Belt Saturn Magnetosphere |
ISSN号 | 2169-9380 |
DOI | 10.1029/2019JA027621 |
英文摘要 | The L shell distributions of MeV electrons in Saturn's radiation belt are investigated orbit by orbit for the 13-year exploration of Cassini. It is found that in addition to the monotonic decrease profiles, there are orbits showing superimposed transient extensions. The extensions are found to stand out above the background population during 50% of belt crossings. We estimate that there is high probability (>72%) that transient extensions contribute more than 10% electron content in the radiation belt. The high occurrence frequency of one extension every 2-3 weeks, together with the relative content, demonstrate that the extensions constitute a regular and fundamental process populating and sustaining the electron belts of Saturn. The transients regularity excludes interplanetary coronal mass ejections as dominant trigger and implies corotation interaction regions and/or internal processes as candidates. Statistical results suggest that the communication of electrons between the middle magnetosphere and the radiation belts is largely through convective radial transport, which produces transient radiation belt extensions. Plain Language Summary The electrons with velocities comparable to light speed residing in Saturn's magnetosphere, namely its electron radiation belt, are highly variable. One prominent feature of this variability is that the shape of permanently trapped population can be severely distorted by episodic, global-scale enhancements. A case study suggested that such an enhancement can be rapidly transmitted from large distances to the radiation belts by global-scale flows. These flows act on electrons in a similar manner engine impulses propel a spacecraft on a different orbit around a celestial body. It is of interest the role played by these enhancements on the evolution of the radiation belt, and which dynamic processes are responsible. In this study, enhancements are sought in the radial distributions of radiation belt electrons for the full, 13-year exploration of Cassini spacecraft. It is demonstrated that these enhancements constitute a regular and fundamental process that populates and sustains the radiation belts of Saturn. The enhancements' regularity implies periodic solar wind perturbations and/or internal magnetospheric dynamics as their major triggers. Among the large number of enhancements analyzed, we find evidence for several traveling radially inward, supporting the scenario that electrons are transported from large distances under the influence of global-scale flows. Key Points The occurrence frequency of Saturn radiation belt transient extensions indicates a possible role for Corotating Integration Regions (CIRs) There is high probability (>72%) that transient extensions contribute >10% electron content in the radiation belt Preference in outside-in cases independent of local time suggests that electron belts may be largely sustained by convective inflow of transient |
WOS关键词 | MAGNETOSPHERE ; INTERCHANGE ; INJECTIONS ; FIELD |
资助项目 | Strategic Priority Research Program of Chinese Academy of Sciences[XDA17010201] ; National Natural Science Foundation of China[41525016] ; National Natural Science Foundation of China[41621063] ; German Space Agency (DLR)[50/OH/1101] ; German Space Agency (DLR)[50/OH/1502] ; Max Planck Society |
WOS研究方向 | Astronomy & Astrophysics |
语种 | 英语 |
WOS记录号 | WOS:000540229100025 |
出版者 | AMER GEOPHYSICAL UNION |
资助机构 | Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; Strategic Priority Research Program of Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; Max Planck Society ; Max Planck Society |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/96903] ![]() |
专题 | 地质与地球物理研究所_中国科学院地球与行星物理重点实验室 |
通讯作者 | Roussos, E. |
作者单位 | 1.Max Planck Inst Solar Syst Res, Gottingen, Germany 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing, Peoples R China 3.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing Natl Observ Space Environm, Beijing, Peoples R China |
推荐引用方式 GB/T 7714 | Yuan, C. -J.,Roussos, E.,Wei, Y.,et al. Sustaining Saturn's Electron Radiation Belts Through Episodic, Global-Scale Relativistic Electron Flux Enhancements[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2020,125(5):13. |
APA | Yuan, C. -J.,Roussos, E.,Wei, Y.,&Krupp, N..(2020).Sustaining Saturn's Electron Radiation Belts Through Episodic, Global-Scale Relativistic Electron Flux Enhancements.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,125(5),13. |
MLA | Yuan, C. -J.,et al."Sustaining Saturn's Electron Radiation Belts Through Episodic, Global-Scale Relativistic Electron Flux Enhancements".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 125.5(2020):13. |
入库方式: OAI收割
来源:地质与地球物理研究所
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