New models of Jupiter's magnetic field constrained by the Io flux tube footprint
New models of Jupiter's magnetic field constrained by the Io flux tube footprint
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DOI：
10.1029/97ja03726
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发表时间：
1998-06-01
影响因子：
2.8
通讯作者：
Satoh, T
中科院分区：
文献类型：
--
作者：
Connerney, JEP;Acuna, MH;Satoh, T
木星行星磁场的球谐模型是通过对木星电离层中木卫一通量管脚位置的现场磁场测量和远程观测得到的。木卫一通量管（IFT）的足迹位于电离层足迹的磁力线跟踪从木卫一的轨道径向距离在赤道平面（5.9木星半径）。IFT足迹是对磁场模型的一个有价值的约束，提供了靠近行星的区域的“地面实况”信息，迄今为止还没有被航天器采样。使用度和阶数为4的球谐展开的行星（“内部”）场和一个明确的模型的磁盘场（“外部”）由于分布电流的磁场表示。模型拟合旅行者1号和先锋11号磁强计观测和IFT足迹的欠定逆问题的部分解决方案，使用广义逆技术。偶极，四极，八极，和一个子集的更高的程度和更高的阶球谐系数的确定和比较与早期的模型。
Spherical harmonic models of the planetary magnetic field of Jupiter are obtained from in situ magnetic field measurements and remote observations of the position of the foot of the Io flux tube in Jupiter's ionosphere. The Io flux tube (IFT) footprint locates the ionospheric footprint of field lines traced from Io's orbital radial distance in the equator plane (5.9 Jovian radii). The IFT footprint is a valuable constraint on magnetic field models, providing "ground truth" information in a region close to the planet and thus far not sampled by spacecraft. The magnetic field is represented using a spherical harmonic expansion of degree and order 4 for the planetary ("internal") field and an explicit model of the magnetodisc for the field ("external") due to distributed currents. Models fitting Voyager 1 and Pioneer 11 magnetometer observations and the IFT footprint are obtained by partial solution of the underdetermined inverse problem using generalized inverse techniques. Dipole, quadrupole, octupole, and a subset of higher-degree and higher-order spherical harmonic coefficients are determined and compared with earlier models.