EGU24-8409, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-8409
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

First observations of whistler waves in Mercury’s magnetosphere by BepiColombo/Mio spacecraft

Fouad Sahraoui1, Mitsunori Ozaki2, Satoshi Yagitani2, Yasumasa Kasaba3, Yoshiya Kasahara2, Shoya Matsuda2, Yoshiharu Omura4, Mitsuru Hikishima5, Laurent Mirioni1, Gérard Chanteur1, Satoshi Kurita4, Satoru Nakazawa6, and Go Murakami6
Fouad Sahraoui et al.
  • 1Laboratoire de Physique des Plasmas, CNRS–École Polytechnique–Sorbonne Université–Université Paris-Saclay–Observatoire de Paris-Meudon, Palaiseau, France.
  • 2Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Japan
  • 3Graduate School of Science, Tohoku University, Sendai, Japan
  • 4Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan
  • 5MagneDesign Corporation, Nagoya, Japan
  • 6Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan

Whistler-mode chorus waves are natural electromagnetic emissions known to play a key role in electron acceleration and loss mechanisms via wave–particle interactions in planetary magnetospheres. Chorus waves have not yet been detected in Mercury’s magnetosphere due to the limited capabilities of the instruments onboard the spacecraft that already visited the planet. Here, we present the first detection of chorus waves in the localized dawn sector during the first and second Mercury flybys by the BepiColombo/Mio spacecraft. Mio’s search coil magnetometers measured chorus waves with tens of picotesla intensities in the dawn sector, while no clear wave activity was observed in the night sector. The simulation results suggest that this dawn-dusk asymmetry could be explained by the impact of background magnetic field inhomogeneities on the nonlinear wave generation process. Potential direct comparisons with electron data will be discussed. This observational evidence is crucial for understanding the dynamics of energetic electron in the localized dawn sector of Mercury’s magnetosphere.

How to cite: Sahraoui, F., Ozaki, M., Yagitani, S., Kasaba, Y., Kasahara, Y., Matsuda, S., Omura, Y., Hikishima, M., Mirioni, L., Chanteur, G., Kurita, S., Nakazawa, S., and Murakami, G.: First observations of whistler waves in Mercury’s magnetosphere by BepiColombo/Mio spacecraft, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8409, https://doi.org/10.5194/egusphere-egu24-8409, 2024.