EGU21-2884
https://doi.org/10.5194/egusphere-egu21-2884
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Foreshock ULF fluctuations near the Moon: THEMIS observations

Anna Salohub, Jana Šafránková, and Zdeněk Němeček
Anna Salohub et al.
  • Faculty of Mathematics and Physics, Charles University, Prague, Czechia (annkasalohub@gmail.com)

The foreshock is a region filled with a turbulent plasma located upstream the Earth’s bow shock where interplanetary magnetic field (IMF) lines are connected to the bow shock surface. In this region, ultra-low frequency (ULF) waves are generated due to the interaction of the solar wind plasma with particles reflected from the bow shock back into the solar wind. It is assumed that excited waves grow and they are convected through the solar wind/foreshock, thus the inner spacecraft (close to the bow shock) would observe larger wave amplitudes than the outer (far from the bow shock) spacecraft. The paper presents a statistical analysis of excited ULF fluctuations observed simultaneously by two closely separated THEMIS spacecraft orbiting the Moon under a nearly radial IMF. We found that ULF fluctuations (in the plasma rest frame) can be characterized as a mixture of transverse and compressional modes with different properties at both locations. We discuss the growth and/or damping of ULF waves during their propagation.

How to cite: Salohub, A., Šafránková, J., and Němeček, Z.: Foreshock ULF fluctuations near the Moon: THEMIS observations, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2884, https://doi.org/10.5194/egusphere-egu21-2884, 2021.

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