Solar Cycle Effects on the Dynamics of Jupiter’s and Saturn’s Magnetospheres
Solar Cycle Effects on the Dynamics of Jupiter’s and Saturn’s Magnetospheres
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太阳周期对木星和土星磁层动力学的影响
DOI：
10.1007/s11207-011-9748-z
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发表时间：
2011
期刊：
影响因子：
2.8
通讯作者：
C. Arridge
中科院分区：
文献类型：
--
作者：
C. Jackman;C. Arridge
与地球相比，木星和土星周围巨大的行星磁层对上游太阳风条件的变化做出了截然不同的反应。航天器曾在太阳周期的极小和极大期间造访过木星和土星。本文从宇宙飞船对太阳风的观测和模型出发，研究了土星和木星上游行星际磁场(IMF)的大尺度结构作为太阳周期的函数。我们给出了太阳风动压以及IMF方位角和子午角在变化的太阳周期条件下的分布，详细说明了它们与Parker预测的比较，以及与我们对5AU和9AU预期日球层结构的总体理解的比较。我们探讨了木星和土星的磁层动力学如何对在不同马赫数条件下太阳周期内不同的太阳风驱动做出反应，并考虑了改变白天耦合如何对夜间磁层反应产生直接影响。我们还讨论了太阳周期中太阳紫外线通量的变化如何影响木星和土星内部磁层中的等离子体和中性环面，并估计了太阳周期对内部驱动磁层动力学的影响。我们最后评论了太阳周期对释放重离子等离子体到日光层的影响，重离子等离子体最终来自木星和土星的卫星。
The giant planetary magnetospheres surrounding Jupiter and Saturn respond in quite different ways, compared to Earth, to changes in upstream solar wind conditions. Spacecraft have visited Jupiter and Saturn during both solar cycle minima and maxima. In this paper we explore the large-scale structure of the interplanetary magnetic field (IMF) upstream of Saturn and Jupiter as a function of solar cycle, deduced from solar wind observations by spacecraft and from models. We show the distributions of solar wind dynamic pressure and IMF azimuthal and meridional angles over the changing solar cycle conditions, detailing how they compare to Parker predictions and to our general understanding of expected heliospheric structure at 5 and 9 AU. We explore how Jupiter’s and Saturn’s magnetospheric dynamics respond to varying solar wind driving over a solar cycle under varying Mach number regimes, and consider how changing dayside coupling can have a direct effect on the nightside magnetospheric response. We also address how solar UV flux variability over a solar cycle influences the plasma and neutral tori in the inner magnetospheres of Jupiter and Saturn, and estimate the solar cycle effects on internally driven magnetospheric dynamics. We conclude by commenting on the effects of the solar cycle in the release of heavy ion plasma into the heliosphere, ultimately derived from the moons of Jupiter and Saturn.