Observations of moon-plasma interactions by orbital and surface experiments
Observations of moon-plasma interactions by orbital and surface experiments
复制标题
通过轨道和表面实验观测月-等离子体相互作用
DOI：
10.1029/rg012i004p00592
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发表时间：
1974
影响因子：
25.2
通讯作者：
B. Lichtenstein
中科院分区：
文献类型：
--
作者：
G. Schubert;B. Lichtenstein
广泛的磁场观测，加上探索者35号月球轨道飞行器和阿波罗表面和轨道实验的关键等离子体测量，已经确定了月球与太阳风和行星际磁场相互作用的基本性质。月球对入射太阳风的有效吸收在月球后面产生了等离子体空洞或空腔。与空腔相关的磁特征的特征在于，与周围行星际等离子体中的平均B水平相比，空腔内的磁场强度B增强，并且在靠近空腔边界处，太阳风使B下降或减小。月球尾流的轴线由于太阳风相对于月球的相对速度而偏离月日线，尾流的横截面为椭圆形，反映了磁声波在太阳风中的各向异性传播。B的增强通常仅在外部观察到，即，在太阳风一侧，磁场强度的稀疏相关下降。在探测器35的高度上，这些都是扰动量级的，而在子卫星的低高度上，它们通常是大的场增加或发生在月球边缘上游或正上方的边缘压缩。月球表面的某些区域似乎比其他区域更能有效地作为临边压缩的来源;相关的区域性质很可能是反射磁化。从源的边缘扰动下游的传播和区域属性可以在经过月球边缘的太阳风流中产生扰动的功效取决于等离子体和行星际磁场的属性。在月球后面的阴影区中，B的主要增强是磁鞘相互作用的一个更显著的特征，而在磁场的高度可变状态下，场强下降和临边压缩变得更难以识别。在磁尾的叶中，在卫星下高度很容易检测到月球磁场。有一个明显的结构与平均场大小测量的阿波罗15号子卫星在地磁尾的等离子体片; B是增强了日侧象限的子卫星轨道。磁场的平均幅度的这种变化可能与等离子体片粒子向地球的漂移有关，从而产生了大约以子卫星的昼侧轨道象限为中心的尾流区域。另外，通量管耗尽地球的月球可以解释所观察到的平均磁场强度的日侧增强。阿波罗在月球表面的粒子和场测量提供了高传导太阳风与月球反射磁场区域相互作用的证据。当Ogo和Vela卫星处于太阳风中，而阿波罗光谱仪位于月球日侧时，Ogo 5，Vela 5和阿波罗12号光谱仪同时获得的离子密度和速度数据也暴露于太阳风等离子体中，表明阿波罗站点的质子速度较小，质子密度较大，而不是自由流太阳风，一个结果质子减速的网站由一个电场建立通过等离子体recrystalmagnetic field相互作用。同时等离子体和磁场的数据，从光谱仪和月球表面磁强计在阿波罗12号的位置，显示压缩的本地reversible场的大太阳风和磁鞘等离子体动态压力。
Extensive magnetic field observations together with crucial plasma measurements by the Explorer 35 lunar orbiter and Apollo surface and orbital experiments have established the basic nature of the moon's interaction with the solar wind and interplanetary magnetic field. The effective absorption of the incident solar wind by the moon creates a plasma void or cavity behind the moon. The cavity-associated magnetic signature is characterized by an enhancement in magnetic field magnitude B within the cavity as compared with the mean level of B in the surrounding interplanetary plasma and dips or decreases in B near the cavity boundaries with the solar wind. The axis of the lunar wake is aberrated from the moon-sun line by the relative velocity of the solar wind with respect to the moon, and the cross section of the wake is elliptical, reflecting the anisotropic propagation of magnetoacoustic waves in the solar wind. Enhancements in B are often observed just external, i.e., on the solar wind side, of the rarefaction-associated dips in the field magnitude. These are of perturbation magnitude at the altitude of Explorer 35, whereas at the low height of the subsatellites they are often large field increases or limb compressions that occur either just upstream of or directly above lunar limbs. Particular surface regions of the moon seem more effective than others as a source of the limb compressions; the pertinent regional property is likely to be remanent magnetization. Propagation of the limb disturbances downstream from the source and the efficacy with which a regional property can create a disturbance in the solar wind flow past the moon's limb depend on properties of the plasma and interplanetary magnetic field. The main enhancement of B in the shadow region behind the moon is a more conspicuous feature of the magnetosheath interaction, whereas the field strength dips and the limb compressions become more difficult to identify in the highly variable state of the magnetic field. In the lobes of the geomagnetic tail, remanent lunar magnetic fields are readily detected at the subsatellite altitude. There is a distinct structure associated with the average field magnitude measured by the Apollo 15 subsatellite in the plasma sheet of the geomagnetic tail; B is enhanced over the day side quadrant of the subsatellite orbit. This variation in the average magnitude of the magnetic field may be associated with the drift of plasma sheet particles toward the earth, creating a wake region centered approximately on the day side orbital quadrant of the subsatellite. Alternatively, flux tube depletion earthward of the moon may explain the observed day side enhancement of average magnetic field magnitude. Apollo particle and field measurements on the lunar surface have provided evidence of a regional interaction of the highly conducting solar wind with lunar remanent magnetic fields. Simultaneous Ogo 5, Vela 5, and Apollo 12 spectrometer data of ion density and velocity taken when the Ogo and Vela satellites were in the solar wind and the Apollo spectrometer was on the lunar day side also exposed to solar wind plasma show that the proton velocity is smaller and the proton density is larger at the Apollo site than in the free stream solar wind, a result of proton deceleration at the site by an electric field established via the plasma-remanent magnetic field interaction. Simultaneous plasma and magnetic field data, from the spectrometer and the lunar surface magnetometer at the Apollo 12 location, show the compression of the local remanent field by large solar wind and magnetosheath plasma dynamic pressures.
太阳风与月球的相互作用
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
Y. Saito;S. Yokota;M. Nishino;T. Yamamoto;H. Tsunakawa
通讯作者：
H. Tsunakawa