Magnetospheres in the Solar System
Magnetospheres in the Solar System
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太阳系中的磁层
DOI：
10.1002/9781119815624.ch29
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Achilleos N
中科院分区：
文献类型：
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作者：
Achilleos N
气态巨行星木星和土星快速旋转的磁层是研究磁化等离子体的天然实验室。几次航天器任务提供了大量的观察结果，证实了“磁盘”结构在这些系统中的核心作用。该区域由延伸电流片产生的磁场和相关的等离子体盘组成。磁盘会根据各种机制而不断变化——包括母行星的旋转、倾斜偶极子；磁层顶电流；特别是对于土星来说，在土星大气层和土星盘之间传递能量的旋转电流系统。在这篇综述中，我们总结了决定木星和土星磁盘结构和动力学的一些机制及其观测特征。然后我们讨论对中磁层区域的磁场和电流进行建模的方法。我们讨论了磁盘对磁层可压缩性的影响，并研究了行星自转和高能粒子在确定等离子盘结构中的作用。
The rapidly rotating magnetospheres of the gas giant planets, Jupiter and Saturn, are natural laboratories for learning about magnetized plasmas. Several spacecraft missions have provided a wealth of observations that confirm the central role of the “magnetodisk” structure in these systems. This region consists of a magnetic field generated by an extended current sheet, and the associated plasma disk. Magnetodisks continually change in response to various mechanisms – including the rotating, tilted dipole of the parent planet; the magnetopause currents; and, for Saturn in particular, rotating systems of current that communicate energy between the planet's atmosphere and the disk. In this review, we provide a summary of some of the mechanisms that determine magnetodisk structure and dynamics at both Jupiter and Saturn, and their observational signatures. We then discuss approaches to modeling the magnetic fields and currents in the middle magnetosphere regions. We discuss the influence of the magnetodisk on magnetospheric compressibility, and investigate the roles of planetary rotation and energetic particles in determining plasmadisk structure.