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Serial optical observation of Jovian plasma processes at the summit of Mauna Kea in Hawaii

在夏威夷莫纳克亚山山顶对木星等离子体过程的连续光学观测

基本信息

批准号：
11691115
负责人：
MORIOKA Akira
金额：
$ 4.22万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11691115/
关键词：
Jovian plasma Jupiter's magnetosphere Io satellite Io volcano Sodium gas Io torus charge exchange molecular ion destraction 木星プラズマイオ火山ガス木星プラズマトーラス惑星プラズマ源巨大惑星

项目摘要

The study, 2-dimensional imaging observations of the D-line emission distribution of logenic sodium atoms, which is regarded as a tracer of logenic volcanic gases, were performed with two field of views (FOV), namely±20Rj (narrow FOV ; Rj : Jovian radius), and ±400Rj (wide FOV). From the observational results, the following characteristics of emission distribution were obtained. In the narrow FOV observation, two different types of distribution extending to〜20Rj, that is, the band-shaped distribution and the spray-shaped distribution, were observed simultaneously. In the wide FOV observation, the elongated oval-like emission distribution extended to as much as 400Rj along the equatorial plane was observed. The east-west intensity asymmetry was also observed, with a dependence on the Io phase angle.Based on the observed images , we then made model analyses to investigate supply processes of sodium atoms and time variation of sodium distribution, and presented the comprehensive source process which can consistently reproduce the observed characteristics both in the narrow and wide FOV observation.From the model analysis for the narrow FOV observational results, it is concluded that the band-shaped distribution is attributed to the molecular ion destruction process, and the typical gyrovelocity of the molecular ions is estimated to be 20km/sec. It is also concluded that the spray-shaped distribution is produced through the charge exchange process. Then a combination of the two processes was examined for the wide FOV observational results. The combined model analysis could fairly reproduce the observed features of the wide extended sodium distribution. In the course of the model analysis, some important physical processes and related parameters are suggested.

用两个视场(FOV)，即±20Rj(窄视场；RJ：木星半径)和±400Rj(宽视场)，对作为火山气体示踪剂的钠原子的D线发射分布进行了二维成像观测。根据观测结果，得到了以下排放分布特征。在窄视场观测中，同时观测到了两种不同类型的分布，即带状分布和喷雾状分布。在宽视场观测中，观察到沿赤道面延伸到400Rj的长椭圆形发射分布。基于观测到的图像，我们对钠原子的供应过程和钠分布的时间变化进行了模型分析，给出了在窄视场观测和宽视场观测中都能一致再现观测特征的综合源过程。对窄视场观测结果的模型分析表明，带状分布归因于分子离子的破坏过程，分子离子的典型回转速度估计为20公里/秒。结果还表明，喷雾状分布是通过电荷交换过程产生的。然后对这两个过程的组合进行了检验，以获得宽视场观测结果。联合模型分析可以很好地再现广泛分布的钠的观测特征。在模型分析过程中，提出了一些重要的物理过程和相关参数。