Global Simulation of the Jovian Magnetosphere: Transitional Structure From the Io Plasma Disk to the Plasma Sheet
Global Simulation of the Jovian Magnetosphere: Transitional Structure From the Io Plasma Disk to the Plasma Sheet
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DOI：
10.1029/2021ja029232
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发表时间：
2021-06
期刊：
影响因子：
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通讯作者：
T. Tanaka;Y. Ebihara;M. Watanabe;S. Fujita;R. Kataoka
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文献类型：
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作者：
T. Tanaka;Y. Ebihara;M. Watanabe;S. Fujita;R. Kataoka
木星有很强的磁场，通过太阳风-木星相互作用形成了巨大的磁层。基于9分量磁流体力学（MHD）和电离层电流守恒原理，再现了所生成的磁层-电离层系统。假设木卫一等离子体发射率为1.4 t/sec，本文再现了自洽的全球磁位形、场向电流（FAC）和极光的产生、8-20 RJ时木卫一等离子体盘的形成、等离子体共转、等离子体盘的不稳定性、20-150 RJ时从木卫一等离子体盘到等离子体片的转变以及等离子体团喷射。盘中旋转的木卫一等离子体形成不稳定性，促进径向扩散。H+由电离层沿沿着高纬度磁场线提供，并与15-20 RJ左右的重离子混合。超过20 RJ，混合等离子体通过超过磁张力的离心力进一步向外扩散。在电离层中，主椭圆出现在余纬13.7°-15.5°。木卫一盘是从主椭圆的低纬度边缘追踪的磁场线的内侧。沿着磁力线，主要的椭圆形映射从外边缘的木卫一盘的整个等离子体片伴随旋转延迟。由于共转限制，对流伴随着等离子体团喷射。等离子体团抛射的反作用影响了木卫一盘的均匀输运过程。向下的FAC发生在极帽中，显示出变化。外部驱动的邓吉对流的区域似乎相当狭窄。
Jupiter has a strong magnetic field, and a huge magnetosphere is formed through the solar wind‐Jupiter interaction. The generated magnetosphere–ionosphere system is reproduced based on the 9‐component Magnetohydrodynamics (MHD) and the current conservation in the ionosphere. Assuming Io plasma emission rate 1.4 t/sec, this paper reproduces self‐consistently global magnetic configuration, generations of the field‐aligned current (FAC) and aurora, formation of the Io plasma disk at 8–20 RJ, plasma corotation, instability in the plasma disk, transition from the Io plasma disk to the plasma sheet at 20–150 RJ, and the plasmoid ejection. The rotating Io plasma in the disk forms instabilities that promotes radial diffusion. H+ is supplied from the ionosphere along high‐latitude magnetic field lines and mixed with heavy ions around 15–20 RJ. Beyond 20 RJ, mixed plasma diffuses further outward by the centrifugal force that can exceed magnetic tension. In the ionosphere, the main oval occurs at 13.7°–15.5° colatitude. The Io disk is inner side of magnetic field lines traced from the low‐latitude edge of the main oval. Along magnetic field lines, the main oval is mapped from the outer edge of the Io disk to the entire plasma sheet accompanying rotation delay. Due to the corotation limit, convection is accompanied by plasmoid ejection. Back reaction of plasmoid ejection affects even transport process in the Io disk. The downward FAC occurs in the polar cap showing variability. The region of externally driven Dungey convection seems quite narrow.