Large-scale Plasma Vortex in the Magnetotail of Venus
-
摘要: 已有研究发现金星磁尾的太阳风氢离子(H+)和金星电离层氧离子(O+)存在大尺度涡流结构, 该涡流从磁尾望向星球是逆时针的. 为了确定该涡流的存在性, 利用金星快车等离子体和高能原子分析仪(Analyzer of Space Plasmas and Energetic Atoms on Venus, ASPERA-4)的Fedorov矫正数据, 分别在金星公转轨道坐标系(VSO)和太阳风电场坐标系(VSE)下对磁尾等离子体流进行了统计分析. 结果显示, 在VSO和VSE坐标系中都存在太阳风H+和金星O+的顺时针涡流结构. 但是从已有的研究结果看, 无论等离子体涡流是逆时针还是顺时针, 其产生的磁场都与已知磁尾磁场结构不相符; 考虑到金星和火星空间环境的相似性及火星磁尾太阳风H+并不存在完整等离子体涡流的情况, 认为金星磁尾可能并不存在大尺度等离子体涡流. 金星的等离子体特征需要未来更多卫星观测研究.Abstract: Using the observations by the Analyzer of Space Plasmas and Energetic Atoms on Venus (ASPERA-4) onboard Venus Express, Previous studies found A large-scale plasma vortices of solar wind hydrogen ions (H+) and Venus ionospheric oxygen ions (O+) in the magnetotail of Venus. The vortex is counterclockwise when viewed from the tail towards the planet. We conducted a statistical analysis of the ASPERA-4 moment data calibrated by Fedorov to investigate the plasma characteristics in Venusian magnetotail. The statistical results showed that there are large-scale vortices of the solar wind H+ and Venus ionospheric O+ in both the Venus-Solar-Orbital (VSO) and Venus-Solar-Electrical (VSE) coordinate systems, but there are clockwise. Considering that neither counterclockwise nor clockwise plasma vortices can generate a magnetic field consistent with the observed magnetic structure in the Venusian magnetotail, and no complete plasma vortex is observed in the Mars magnetotail with a magnetic structure similar to that of Venusian magnetotail, concluded that there may not be large-scale plasma vortices in the Venusian magnetotail, and that more satellite observations are needed in the future to investigate the plasma characteristics on Venus.
-
Key words:
- Magnetotail /
- Plasma vortex /
- Magnetic field structure /
- Venus /
- Mars
-
图 1 VSO坐标系中金星快车在金星周围观测到的太阳风H+与金星电离层O+密度n和速度分量(vx, vy, vz) 的平均值分布(VSO坐标系为金星太阳风公转轨道坐标系. 黑色曲线代表金星弓激波位置, 黑色矩形代表金星磁尾边界, 黑色半圆代表金星)
Figure 1. Average values of the density n and velocity components (vx, vy, vz) of the solar wind H+ and Venus ionospheric O+ observed by the Venus Express around Venus in the Venus-Solar-Orbital (VSO) coordinate system (Outermost black curve represents the location of the Venus bow shock, the black rectangular box represents the boundary of the Venusian magnetotail, and the black semicircle represents Venus)
图 2 VSO坐标系中金星快车在金星夜侧 (x < 0) 观测到的太阳风H+与金星电离层O+密度n和速度分量(vx, vy, vz)的平均值分布(VSO坐标系为金星太阳风公转轨道坐标系.内侧黑色圆圈代表金星, 外侧黑色圆圈代表金星磁尾边界)
Figure 2. Average values of the density n and velocity components (vx, vy, vz) of the solar wind H+ and the Venus ionospheric O+ observed by Venus Express in the night side of Venus (x < 0) in the VSO (Venus-Solar-Orbital) coordinate system coordinate system (Inner black circle represents Venus, and the outer black circle represents the boundary of the Venusian magnetotail)
图 3 VSE坐标系中金星快车在金星夜侧(x < 0)观测到的太阳风H+与金星电离层O+的密度n和速度分量(vx, vy, vz)平均值分布 (VSE为金星太阳风电场坐标系. 黑色曲线代表金星弓激波位置, 内侧黑色圆圈代表金星, 外侧黑色圆圈代表金星磁尾边界)
Figure 3. Average density n and velocity components (vx, vy, vz) of solar wind H+ and Venus ionospheric O+ on the nightside of Venus (x < 0) were observed by Venus Express in the VSE (Venus-Solar-Electrical) coordinate system (Inner black circle represents Venus, and the outer black circle represents the boundary of the Venusian magnetotail)
图 4 VSE坐标系中金星快车在xz平面周围(|y| < 1)观测到的太阳风H+与金星电离层O+的密度n和速度分量(vx, vy, vz)平均值分布(VSE为金星太阳风电场坐标系. 最外面黑色曲线代表金星弓激波位置, 黑色矩形方框代表金星磁尾边界, 黑色圆圈代表金星)
Figure 4. Average values of the density n and velocity components (vx, vy, vz)of the solar wind H+ and the Venus ionospheric O+ observed by Venus Express around the xz plane (|y|<1) in the VSE (Venus-Solar-Electrical) coordinate system (Outermost black curve represents the location of the Venus bow shock, the black rectangular box represents the boundary of the Venusian magnetotail, and the black circle represents Venus)
图 5 VSO坐标系和VSE坐标系金星快车在金星夜侧观测到的金星磁尾太阳风H+和金星电离层O+的速度涡流(箭头方向和长度分别表示速度vy,z的方向和大小, 内外圆圈分别代表金星和金星磁尾边界)
Figure 5. Velocity vortices of the solar wind H+ and the Venus ionospheric O+ in the magnetotail observed by the Venus Express in the night side of Venus, in VSO coordinate system and VSE coordinate system (Direction and length of the arrows represent the direction and magnitude of the velocity vy,z. The inner and outer circles represent Venus and the boundary of the Venusian magnetotail, respectively
-
[1] Russell C T, Elphic R C, Slavin J A. Initial Pioneer Venus Magnetic Field Results: Nightside Observations[J]. Science, 1979, 205: 114-116 doi: 10.1126/science.205.4401.114 [2] Luhmann J G, Ledvina S A, Russell C T. Induced magnetospheres[J]. Advances in Space Research, 2004, 33: 1905-1912 doi: 10.1016/j.asr.2003.03.031 [3] Barabash S, Fedorov A, Sauvaud J J, et al. The loss of ions from Venus through the plasma wake[J]. Nature, 2007, 450: 650-653 doi: 10.1038/nature06434 [4] Martinecz C, Fränz M, Woch J, et al. Location of the bow shock and ion composition boundaries at Venus - initial determinations from Venus Express ASPERA-4[J]. Planetary & Space Science, 2008, 56(6): 780-784 [5] Smrekar, Suzanne E, Ellen R S, et al. Chapter 15 - Venus: Surface and Interior[M]// Tilman Spohn, Doris Breuer, Torrence V J. Encyclopedia of the Solar System (3rd). Boston: Elsevier, 2014: 323–341 [6] Gringauz K I, Bezrukikh V V, Breus T K, et al. Plasma Observations Near Venus Onboard the Venera 9 and 10 Satellites by Means of Wide-Angle Plasma Detectors[M]// Williams D J. Physics of Solar Planetary Environments: Proceedings Of the International Symposium on Solar‐Terrestrial Physics. Colorado, 1976: 918-932 [7] Keldysh M V. Venus exploration with the Venera 9 and Venera 10 spacecraft[J]. Icarus, 1977, 30(4): 605-625 doi: 10.1016/0019-1035(77)90085-9 [8] Dolginov S S. Magnetic Fields in the Vicinity of Venus According to “Venere and” and “Mariner” Data[M]//Robertson P C. Abstracts of Planetary Institute Topical Conference . Houston: the Lunar and Planetary Institute, 1978(348): 22 [9] Verigin M I , Gringauz K I , Gombosi T, et al. Plasma near Venus from the Venera-9 and 10 wide-angle analyzer data[J]. Journal of Geophysical Research Space Physics, 1978, 83(A8): 3721-3728 [10] Russell C T. The Pioneer Venus mission[M]. Washington DC American Geophysical Union Geophysical Monograph Series, 1992, 66: 225-236 [11] Russell C T, Luhmann J G, Strangeway R G. The Solar Wind Interaction with Venus through the Eyes of the Pioneer Venus Orbiter[J]. Planetary and Space Science, 2006, 54: 1482-1495 doi: 10.1016/j.pss.2006.04.025 [12] Titov D V, Svedhem H, Taylor F W, et al. Venus Express: Highlights of the Nominal Mission. Solar System Research, 2009, 43 (3): 185-209 [13] Luhmann J. G. , Kozyra J. U. Dayside pickup oxygen ion precipitation at Venus and Mars: Spatial distributions, energy deposition and consequences[J]. Journal of Geophysical Research Space Physics, 1991, 96, 5457–5467 [14] Villarreal M N , Russell C T , Wei H Y, et al. Characterizing the low-altitude magnetic belt at Venus: Complementary observations from the Pioneer Venus Orbiter and Venus Express[J]. Journal of Geophysical Research Space Physics, 2015, 120(3): 2232-2240 [15] Rong Z J, Barabash S, Futaana Y, et al. Morphology of magnetic field in near-Venus magnetotail: Venus Express observations[J]. Journal of Geophysical Research Space Physics, 2014, 119(11): 8838-47 doi: 10.1002/2014JA020461 [16] Dubinin E , Fraenz M , Zhang T L, et al. Plasma in the near Venus tail: Venus Express observations[J]. Journal of Geophysical Research: Space Physics, 2013, 118(12): 7624-7634 [17] Zhang T L, Lu Q M, Baumjohann W, et al. Magnetic Reconnection in the Near Venusian Magnetotail[J]. Science, 2012, 336: 567-70 doi: 10.1126/science.1217013 [18] Lundin R, Barabash S , Futaana Y, et al. A large-scale flow vortex in the Venus plasma tail and its fluid dynamic interpretation[J]. Geophysical Research Letters, 2013, 40(7): 1273-1278 [19] Pérez-de-Tejada H, Lundin R. Solar Cycle Variations in the Position of Vortex Structures in the Venus Wake[M]//Bevelacqua J. Solar System Planets and Exoplanets, 2021: 63-77 [20] Durand-Manterola, Héctor Javier, Alberto Flandes. Plasma Vortices Driven by Magnetic Torsion Generated by Electric Currents in Non-Magnetic Planetary Wakes[J]. Advances in Space Research, 2022, 69(10): 3902-3908 doi: 10.1016/j.asr.2022.03.002 [21] Chai L H, Wei Y, Wan W, et al. An induced global magnetic field looping around the magnetotail of Venus[J]. Journal of Geophysical Research Space Physics, 2016, 121(1): 688-698 doi: 10.1002/2015JA021904 [22] Barabash S, Sauvaud J A, Gunell H, et al. The Analyser of Space Plasmas and Energetic Atoms (ASPERA-4) for the Venus Express Mission[J]. Planetary and Space Science, 2007, 55: 1772-1792 doi: 10.1016/j.pss.2007.01.014 [23] Zhang T L, Baumjohann W, Delva M, et al. Magnetic Field Investigation of the Venus Plasma Environment: Expected New Results from Venus Express[J]. Planetary and Space Science, 2006, 54: 1336-43 doi: 10.1016/j.pss.2006.04.018 [24] Chai L H, Fraenz M, Wan W, et al. IMF control of the location of Venusian bow shock: The effect of the magnitude of IMF component tangential to the bow shock surface[J]. Journal of Geophysical Research Space Physics, 2014, 119(12): 9646-9475 [25] Chai L H, Wan W X, Wei Y, et al. The Induced Global Looping Magnetic Field on Mars[J]. The Astrophysical Journal Letters, 2019, 871(2): L27 doi: 10.3847/2041-8213/aaff6e [26] Dubinin E, Modolo R, Fraenz M, et al. The Induced Magnetosphere of Mars: Asymmetrical Topology of the Magnetic Field Lines[J]. Geophysical Research Letters, 2019, 46(22): 12722-12730 doi: 10.1029/2019GL084387 -
下载:
点击查看大图
计量
- 文章访问数: 85
- HTML全文浏览量: 14
- PDF下载量: 15
- 被引次数: 0
