Effects of magnetic anomalies discovered at Mars on the structure of the Martian ionosphere and solar wind interaction as follows from radio occultation experiments
Effects of magnetic anomalies discovered at Mars on the structure of the Martian ionosphere and solar wind interaction as follows from radio occultation experiments
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DOI：
10.1029/1999ja000212
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发表时间：
2000-07
影响因子：
--
通讯作者：
N. Ness;M. Acuna;J. Connerney;A. Kliore;T. Breus;A. M. Krymskii;P. Cloutier;S. Bauer
中科院分区：
文献类型：
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作者：
N. Ness;M. Acuna;J. Connerney;A. Kliore;T. Breus;A. M. Krymskii;P. Cloutier;S. Bauer
在火星上通过无线电掩星实验得到的电子密度曲线的斜率与金星无磁场电离层的电子密度曲线的行为相比，揭示了太阳天顶角的不同变化。火星-全球勘测者（MGS）宇宙飞船获得的结果表明，火星上存在着高度可变的、非常局域化的地壳磁场。针对金星和火星电离层的差异，分析了水手9号和海盗1号上的无线电掩星方法在高于无磁场电离层光平衡区顶部边界的高度上获得的电子密度剖面的尺度高度。在海拔180 ~ 250 km范围内，局部平均尺度高度的增加可能是与磁异常相关的非水平磁场的影响，也可能是在无磁场的电离层中扩散平衡的影响。选取了电子密度谱标度高度较平均标度高度有所提高的区域。在这些选定的地区，研究了MGS MAG/ER在海拔120-250 km处测量的磁场与当地天顶方向之间的夹角。
The slopes of the electron density profiles obtained by radio occultation experiments at Mars revealed different variations with solar zenith angle in comparison with behavior of the electron density profiles in the magnetic field free ionosphere of Venus. The results obtained by the Mars-Global-Surveyor (MGS) spacecraft show the existence of highly variable and very localized magnetic fields of crustal origin at Mars. Addressing the difference between the ionosphere at Venus and Mars, the scale heights of electron density profiles obtained by radio occultation methods onboard Mariner 9 and Viking 1 are analyzed at altitudes higher than the topside boundary of the photoequlibrium region in the magnetic field-free ionosphere. The local increase of the mean scale height in the altitude region 180–250 km is assumed to be either an effect of a nonhorizontal magnetic field associated with the magnetic anomalies or diffusive equilibrium in the magnetic field free ionosphere. The areas where the scale height of electron density profile is increased in comparison with average one have been selected. The angle between the magnetic field measured by MGS MAG/ER at altitudes 120–250 km and local zenith direction is investigated throughout these selected areas.