A generalized hinged-magnetodisc model of Jupiter's nightside current sheet
A generalized hinged-magnetodisc model of Jupiter's nightside current sheet
复制标题
木星夜侧电流片的广义铰接磁盘模型
DOI：
10.1029/92ja00169
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发表时间：
1992
影响因子：
--
通讯作者：
K. Khurana
中科院分区：
文献类型：
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作者：
K. Khurana
对于访问过木星磁尾的三个航天器中的每一个，都为木星的夜侧电流片建立了独立的铰链磁盘模型。从任何一次相遇中得出的模型参数(特别是铰点距离)被发现不适用于来自其他相遇的数据。例如，对于先锋10号电流片的交叉，戈尔茨(1976,1979)发现电流片并没有明显偏离偶极子磁赤道弯曲。另一方面，Behannon等人。(1981)和Goertz(1981)发现，对于旅行者1号的观测，有必要在他们的模型中引入圆柱径向距离60RJ附近的电流片铰接。Behannon等人发现旅行者2号的铰链距离更小(∼40 RJ)。(1981)。Vasyliunas和Dessler(1981)批评了铰链磁盘模型，因为它们未能通过使用一组参数来组织来自所有三个航天器的当前薄片交叉数据。Khurana和Kivelson(1989)在评估几种木星电流片模型的研究中指出，如果磁尾的铰接是由太阳风强迫引起的，那么铰接距离应该用木星-太阳-磁层(JSM)x坐标来参数化，而不是柱面(或行星中心)径向距离。在本文中，我们发展了一个包含这一建议的定量铰接磁盘广义模型，并在引入三个拟合参数的情况下解释了所有三次飞行的当前片面交叉数据。在模拟和观察到的当前薄板交叉位置之间的均方根误差方面，本模型与先前发表的模型相当或略好于先前发表的模型。增加的新奇之处在于，与以前的模型不同，通用模型不需要为三次相遇中的每一次都设置不同的参数。给出了我们的结果与以前的模型的比较。
For each of the three spacecraft that have visited the magnetotail of Jupiter, independent hinged-magnetodisc models have been constructed for Jupiter's nightside current sheet. Model parameters (especially the hinge point distance) derived from any one encounter were found to be inapplicable to data from other encounters. For example, for the Pioneer 10 current sheet crossings, Goertz (1976, 1979) found that the current sheet does not significantly bend away from the dipole magnetic equator. On the other hand, Behannon et al. (1981) and Goertz (1981) found it necessary to introduce hinging of the current sheet in their models near a cylindrical radial distance of 60 RJ for Voyager 1 observations. The hinge distance was found to be even smaller (∼ 40 RJ) for Voyager 2 by Behannon et al. (1981). Vasyliunas and Dessler (1981) have criticized hinged magnetodisc models for their failure to organize current sheet crossing data from all three of the spacecraft by using a single set of parameters. Khurana and Kivelson (1989) in a study that evaluated several models of Jupiter's current sheet pointed out that if the hinging of the magnetotail is caused by solar wind forcing then the hinging distance should be parameterized in terms of Jupiter-Sun-magnetospheric (JSM) x coordinate instead of the cylindrical (or planetocentric) radial distance. In this paper we develop a quantitative hinged-magnetodisc generalized model that incorporates this suggestion and explains the current sheet crossing data from all three of the flybys with the introduction of only three fitting parameters. The present model is comparable to or slightly superior than the models published previously in terms of rms error of fit between the modeled and observed current sheet crossing locations. The added novelty is that unlike the previous models the generalized model does not require a different set of parameters for each of the three encounters. A comparison of our results with the earlier models is presented.