Mercury’s magnetosphere–solar wind interaction for northward and southward interplanetary magnetic field: Hybrid simulation results
Mercury’s magnetosphere–solar wind interaction for northward and southward interplanetary magnetic field: Hybrid simulation results
复制标题
水星磁层-太阳风相互作用对北向和南向行星际磁场的影响：混合模拟结果
DOI：
10.1016/j.icarus.2010.01.008
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发表时间：
2010
期刊：
影响因子：
3.2
通讯作者：
J. Slavin
中科院分区：
文献类型：
--
作者：
P. Trávnícek;D. Schriver;P. Hellinger;D. Herčík;B. Anderson;M. Sarantos;J. Slavin
在信使号与水星头两次相遇的背景下，对向北和向南的行星际磁场(IMF)方向的水星磁层-太阳风相互作用的全球混合模拟进行了分析。全球动力学模拟揭示了这种相互作用的基本结构，包括弓形激波、离子前震、磁鞘、尖点区、磁层顶和在磁层内围绕行星形成的闭合离子环带。两种不同的IMF取向导致了不同的离子前震位置和不同的磁层性质：与向北的IMF相比，向南的IMF的日侧磁层较小，尖点位于较低的纬度，而向南的IMF的夜侧磁层较大，并显示出具有磁重联和等离子体形成特征的薄电流片。对于两个IMF取向，离子前震和准平行磁鞘表现为离子束驱动的大幅度振荡，而准垂直磁鞘表现为离子温度各向异性驱动的波活动。水星带中的离子在被水星表面吸收或从磁层逃逸之前，会在有限的时间内保持准捕获状态。将模拟结果与信使的观测结果进行了比较。
Analysis of global hybrid simulations of Mercury’s magnetosphere–solar wind interaction is presented for northward and southward interplanetary magnetic field (IMF) orientations in the context of MESSENGER’s first two encounters with Mercury. The global kinetic simulations reveal the basic structure of this interaction, including a bow shock, ion foreshock, magnetosheath, cusp regions, magnetopause, and a closed ion ring belt formed around the planet within the magnetosphere. The two different IMF orientations induce different locations of ion foreshock and different magnetospheric properties: the dayside magnetosphere is smaller and cusps are at lower latitudes for southward IMF compared to northward IMF whereas for southward IMF the nightside magnetosphere is larger and exhibits a thin current sheet with signatures of magnetic reconnection and plasmoid formation. For the two IMF orientations the ion foreshock and quasi-parallel magnetosheath manifest ion-beam-driven large-amplitude oscillations, whereas the quasi-perpendicular magnetosheath shows ion-temperature-anisotropy-driven wave activity. The ions in Mercury’s belt remain quasi-trapped for a limited time before they are either absorbed by Mercury’s surface or escape from the magnetosphere. The simulation results are compared with MESSENGER’s observations.