A Study of Jupiter's Radio Emission Mechanism by the Simultaneous Advanced Observations of Jupiter's Radio and Infrared Aurora Emissions

通过对木星射电和红外极光发射的同时高级观测研究木星的射电发射机制

• 批准号: 14540417
• 负责人: IMAI Kazumasa
• 金额: $ 1.98万
• 依托单位: Kochi National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540417/
• 关键词: Jupiter; Natural Radio Emissions; Decametric Wave; Magnetosphere; Dynamic Spectrum; Modulation Lanes; Model; Radio Source

Frequency-time dynamic spectra of Jupiter's decametric radio emission display a complex structure on several different time scales. One of the characteristic spectral patterns on a time scale of a few tens of seconds are the modulation lanes discovered by Riihimaa in 1968. We developed a model for the mechanism responsible for their production in which the free parameters can be adjusted to provide a very close fit with the observations [Imai et al., 1992a,1992b,1997,2002]. In our model, we propose the existence of a grid-like interference screen composed of field-aligned columns of enhanced or depleted plasma density located along the longitudinal direction near Io's orbit.We made a statistical analysis of Io-A and Io-B source modulation lanes observed by wideband spectrographs at Oulu, Florida, and Nancay. Using the modulation lane method it was possible to make relatively precise measurements of the value of the cone half-angle of the hollow-cone emission beam and the System III source locations for the Io-A and Io-B sources. The measured cone half-angles for the two sources were both within about 3 degrees of 60 degrees. And the measured typical ranges of source System III longitude are 130 to 205 degrees for Io-A and 125 to 215 degrees for Io-B. These results show that the radio active regions of Io-A and Io-B are sharing the same source System III longitude. Based on these results, we are able to show for the first time a more realistic view of the location and beaming of Jupiter's radio sources using a 3D computer graphic animation (http://jupiter.kochi-ct.jp/cg/). This can provide a very important piece of information in the investigation of the mechanism responsible for Jupiter's decametric radio emission.

木星deTametric无线电发射的频率时间动态光谱在几个不同的时间尺度上显示出复杂的结构。时间尺度上几十秒钟的特征光谱模式之一是Riihimaa在1968年发现的调制车道。我们开发了一种模型，用于使其生产的机制，在该机制中，可以调整免费参数以提供非常接近的参数适合观察结果[Imai等，1992a，1992b，1997,2002]。在我们的模型中，我们提出了一个网格样干扰屏幕的存在，该屏幕由位于IO轨道附近的纵向方向的增强或耗尽的等离子体密度组成，我们对IO-A和IO-B源进行了统计分析。宽带光谱仪在Oulu，佛罗里达州和Nancay观察到的调节车道。使用调制车道方法，可以对IO-A和IO-B源的空心发射光束的锥半角度和系统III源位置进行相对精确的测量。这两个源的测得的锥半角度均在约3度的60度内。源系统III经度的典型范围为IO-A的130至205度，IO-B为125至215度。这些结果表明，IO-A和IO-B的无线电区域正在共享相同的源系统III经度。基于这些结果，我们能够首次使用3D计算机图形动画（http://jupiter.kochi-ct.jp/cg/）首次展示木星无线电源的位置和光束。在调查负责木星deTametric无线电发射机制的调查中，这可以提供非常重要的信息。

项目成果

Modeling of Modulation Lanes in Jupiter's Decametric Radio Spectra

木星十度射电频谱中调制通道的建模

• 期刊: Ph.D.Thesis (Informatics), Kyoto University
• 作者: K.Imai

Io-A Source Modulation Lanes in Jupiter's Decametric Radio Spectra

木星十度射电频谱中的 Io-A 源调制通道

• 发表时间: 2004
• 期刊: Asia Oceania Geosciences Society 1st Annual Meeting, Singapore Vol.1
• 作者: Kazumasa Imai

Measurement of Jupiter's Decametric Radio Source Parameters by the Modulation Lane Method

调制巷法测量木星十度射电源参数

• 发表时间: 2002
• 期刊: Journal of Geophysical Research 107,A6
• 作者: J.T.Clarke;D.Grodent;S.W.H.Cowley;E.J.Bunce;Kazumasa Imai
• 通讯作者: Kazumasa Imai

Kazumasa Imai: "Modeling of Modulation Lanes in Jupiter's Decametric Radio Spectra"京都大学博士論文(情報学). 108 (2002)

Kazumasa Imai：“木星十度射电频谱中的调制通道建模”京都大学博士论文（信息学）108（2002）。

Investigation of Jupiter's Radio Sources by the Modulation Lane Method

用调制巷法研究木星的射电源

• 发表时间: 2002
• 期刊: Proceeding of Planetary Magnetosphere and Atmosphere, Tohoku University
• 作者: K.Imai