Periodic perturbations in Saturn's magnetic field
Periodic perturbations in Saturn's magnetic field
复制标题
土星磁场的周期性扰动
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
M. Dougherty
中科院分区：
文献类型：
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作者：
S. A. Espinosa;M. Dougherty
对土星磁层的所有现有磁场数据进行了分析。这些数据来自三艘航天器与土星的相遇（先锋 11 号、航海者 1 号和旅行者 2 号）。为了对三个磁场数据集进行直接比较，它们都表达在同一个地心球极坐标系中。在先锋 11 号（整个遭遇）和航海家 2 号（入境）的情况下，在磁场的径向和/或方位角分量中观察到了几个纳特斯拉的令人惊讶的扰动（周期接近土星的自转周期）。结果表明，偶极子倾斜和/或电流片交叉不太可能是造成这种周期性扰动的原因。这与现有土星磁场模型产生的可忽略不计的磁偶极子倾斜一致。
Analysis of all the existing magnetic field data from Saturn's magnetosphere is carried out. These data arise from the three spacecraft encounters with Saturn (Pioneer 11, Voyager 1 and 2). In order to carry out a direct comparison between the three magnetic field data sets, they are all expressed in the same planetocentric spherical polar coordinate system. In the cases of Pioneer 11 (whole encounter) and Voyager 2 (inbound) a surprising perturbation of a few nanoteslas is observed (with a period close to Saturn's rotation period) in the radial and/or azimuthal components of the magnetic field. It is shown that a dipole tilt and/or current sheet crossings are unlikely causes for such periodic perturbations. This is in agreement with the negligible magnetic dipole tilt resulting from the existing models of Saturn's magnetic field.