Whistler-mode and ULF waves and their association with solar wind plasmas observed upstream of Martian bow shock

Whistler-mode and ULF waves upstream of planetary bow shock play important role in energy transfer and dissipation processes in the planetary environment. A series of whistler-mode waves with their frequencies centered at ~0.4 Hz, accompanied by another series of ~0.04 Hz ULF waves, were observed upstream of the Martian bow shock by MAVEN on 2015 August 14. During the occurrence of waves, a significant flux enhancement of high-energy protons up to ∼10 keV, as well as the response of electrons to the ULF waves, were also observed. The pitch angle distributions of electrons were modulated differently according to electrons’ energies. Preliminary dispersion analysis suggests that the solar wind condition was capable of generating ULF waves by ion-ion instabilities, while the observed whistler-mode waves have the potential of resonating with protons of ∼1 keV with large pitch angles up to nearly perpendicular to the background magnetic field. Our results indicate the possible connection between co-existence of waves and the origin of energized protons through wave-particle interactions in the Martian environment.