EGU2020-1890, updated on 06 Jan 2023
EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Unusual location of the geotail magnetopause at lunar distance: ARTEMIS observation

Wensai Shang1,2,3, Binbin Tang2, Quanqi Shi1, Anmin Tian1, Xiaoyan Zhou4, Zhonghua Yao5, Alex W. Degeling1, Iain Jonathan Rae6, Suiyan Fu7, Jianyong Lu3, Zuyin Pu7, Andrew N. Fazakerley6, Malcolm M. Dunlop8, Gabor Facsko9, Jiang Liu4, and Ming Wang3
Wensai Shang et al.
  • 1Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, China.
  • 2State Key Laboratory of Space Weather, Center for Space and Applied Research, Chinese Academy of Sciences, Beijing, China.
  • 3Institute of Space Weather, Nanjing University of Information, Science & Technology, Nanjing, China.
  • 4Earth, Planetary, and Space Sciences, UCLA, USA.
  • 5Laboratoire de Physique Atmosphérique et Planétaire, STAR institute, Université de Liège, Liège, Belgium.
  • 6UCL Mullard Space Science Laboratory, Dorking, RH5 6NT, UK.
  • 7School of Earth and Space Sciences, Peking University, Beijing, China.
  • 8Space Sciences Division, SSTD, Rutherford Appleton Laboratory, UK.
  • 9Rhea System GmbH, TIZ Building, Robert Bosch Str. 7, 64293 Darmstadt, Germany.

The Earth’s magnetopause is highly variable in location and shape, and is modulated by solar wind conditions. On 8 March 2012, the ARTEMIS probes were located near the tail current sheet when an interplanetary shock arrived under northward interplanetary magnetic field (IMF) conditions, and recorded an abrupt tail compression at ~(-60, 0, -5) RE in Geocentric Solar Ecliptic (GSE) coordinate in the deep magnetotail. Approximately 10 minutes later, the probes crossed the magnetopause many times within an hour after the oblique interplanetary shock passed by. The solar wind velocity vector downstream from the shock was not directed along the Sun-Earth line, but had a significant Y component. We propose that the compressed tail was pushed aside by the appreciable solar wind flow in the Y direction. Using a virtual spacecraft in a global magnetohydrodynamic (MHD) simulation, we reproduce the sequence of magnetopause crossings in the X-Y plane observed by ARTEMIS probes under oblique shock conditions, demonstrating that the compressed magnetopause is sharply deflected at lunar distances in response to the shock and solar wind VY effects. The results of the two different global MHD simulations show that the shocked magnetotail at lunar distances is mainly controlled by the solar wind direction with a timescale of about a quarter hour, which appears to be consistent with the windsock effect. The results also provide some references for investigating interactions between the solar wind/magnetosheath and lunar nearside surface during full moon time intervals, which should not happen in general.

How to cite: Shang, W., Tang, B., Shi, Q., Tian, A., Zhou, X., Yao, Z., Degeling, A. W., Rae, I. J., Fu, S., Lu, J., Pu, Z., Fazakerley, A. N., Dunlop, M. M., Facsko, G., Liu, J., and Wang, M.: Unusual location of the geotail magnetopause at lunar distance: ARTEMIS observation, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1890,, 2020.


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