A theory of the Io phase asymmetry of the Jovian decametric radiation
A theory of the Io phase asymmetry of the Jovian decametric radiation
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木星十度辐射Io相位不对称理论
DOI：
10.1029/ja088ia03p02010
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发表时间：
1982
影响因子：
--
通讯作者：
M. Goldstein
中科院分区：
文献类型：
--
作者：
K. Hashimoto;M. Goldstein
我们对木卫一相关的木星十米波辐射出现概率的不对称性提出一种解释。我们发现这种不对称性的产生是因为当木卫一位于环面的北部时，产生的向南传播的阿尔文波比向北传播的更强。这些波在从南部电离层反射后会在北部电离层激发十米波辐射。这种不对称性是由阿尔文波的传播时间以及磁场（阿尔文翼）沿此轨迹的弯曲所导致的。利用木星电离层中的三维射线追踪程序计算了十米波辐射的射线路径。针对木星电离层和全球磁场的两种模型以及辐射频率与X模式截止频率之比的几种选择，计算了预期概率图的变化。还在该模型的背景下讨论了出现概率对地球的木星赤纬的依赖性。
We propose an explanation of an asymmetry in the occurrence probability of the Io-dependent Jovian decametric radiation. We find that this asymmetry arises because when Io is in the northern part of the torus, more intense Alfven waves are generated propagating southward than northward. These waves then cause the excitation of decametric radiation in the northern ionosphere after reflection from the southern ionosphere. The asymmetry then results from the propagation time of the Alfven wave and the bending of the magnetic field (Alfven wing) along this trajectory. The ray paths of the decametric radiation are calculated using a three-dimensional ray-tracing program in the Jovian ionosphere. Variations in the expected probability plots are computed for two models of the Jovian ionosphere and global magnetic field, as well as for several choices of the ratio of the radiated frequency to the X mode cutoff frequency. The dependence of the occurrence probability on the Jovian declination of the earth is also discussed in the context of this model.