Spatial distribution of Martian upstream-generated magnetosonic waves observed by Tianwen-1 and their possible wave–particle interactions based on a case study

Using magnetic field and ion measurements from Tianwen-1 acquired between November 2021 and August 2024, we investigate the spatial distribution of Martian magnetosonic (MS) waves and their possible wave−particle interactions. MS wave events are identified using criteria based on frequency range, propagation angle, polarization, compressional power ratio, and event duration. The statistical results show that these waves occur predominantly near the Martian bow shock, where the occurrence rate exceeds 50%. Owing to the high-apogee orbit of Tianwen-1, the present survey also extends its observational coverage to higher-altitude and more tailward regions than previous studies. To further examine the physical properties of these waves, we analyze a representative MS wave event and evaluate its dispersion relation under different background plasma conditions. The results indicate that the wave dispersion is strongly affected by the background magnetic field strength and plasma density, whereas the influence of propagation angle is comparatively weaker within the quasi-perpendicular range. We also estimate the resonant energy ranges for H⁺, O⁺, and O₂⁺ ions. The results show clear species-dependent differences, with larger variations for O⁺ and O₂⁺ than for H⁺ under the selected wave and plasma parameters. These findings provide new observational constraints on the role of MS waves in the solar wind interaction with Mars and their potential contribution to ion energization in the Martian plasma environment.