Survey of 1-Hz waves in the near-Venusian space: Venus Express observations
Survey of 1-Hz waves in the near-Venusian space: Venus Express observations
复制标题
近金星空间 1 Hz 波的调查：金星快车观测
DOI：
10.1016/j.pss.2020.104933
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发表时间：
2020-08-01
影响因子：
2.4
通讯作者：
Zhang, T. L.
中科院分区：
文献类型：
--
作者：
Xiao, S. D.;Wu, M. Y.;Zhang, T. L.
本文利用金星快车2006年5月至2012年8月的32 Hz磁场数据，给出了近金星空间1 Hz波的全球空间分布。 1 Hz 波的出现率在金星弓形激波附近达到最大，而在上游则随着远离激波的距离而降低。金星弓激波的下游，一些 1 Hz 的波在磁鞘中扫过。然而，这些波无法进入感应磁层。 1 Hz 波的分布显示出太阳周期的变化，这可能是新生拾取离子的影响。在-E半球弓激波附近波的发生率较高，在+E半球波可以向上游传播更远的距离，而下游1 Hz波的发生率没有表现出明显的半球不对称性。此外，近金星空间的1Hz波在准平行前震区比准垂直区出现率更高、分布更广泛。由此可见，准平行区的1Hz波受Landau阻尼的影响较小，在前震中可以传播得更远。
With 32 Hz magnetic field data of Venus Express from May 2006 to August 2012, the global spatial distributions of 1-Hz waves in the near-Venusian space are presented in this paper. The occurrence rate of 1-Hz waves is maximized near the Venusian bow shock and decreases in the upstream with the distance away from the shock. Downstream of Venusian bow shock, some 1-Hz waves are swept in the magnetosheath. However, these waves cannot enter the induced magnetosphere. The distribution of 1-Hz waves shows a solar cycle variation which could be the influence of the newborn pickup ions. The wave occurrence rate is higher near the bow shock in the -E hemisphere, and the waves can propagate upstream farther in the +E hemisphere, while the occurrence rate of the downstream 1-Hz waves shows no clear hemispheric asymmetry. In addition, the 1-Hz waves in the near-Venusian space have a higher occurrence rate and a more widespread distribution in the quasiparallel foreshock region than in the quasi-perpendicular region. It can be inferred that the 1-Hz waves in the quasi-parallel region are less affected by Landau damping and they can propagate farther in the foreshock.