A Parametric Study of Locally Generated Magnetosonic Waves by Ring‐Beam Hot Protons in the Martian Heavy Ion‐Rich Environment

Magnetosonic (MS) waves with frequencies above the proton gyrofrequency can be locally generated by ring‐beam protons in the Martian heavy ion‐rich ionosphere. In this study, we conduct a parametric analysis to investigate the effects of heavy ion concentrations, energy ( E rb ), and angle ( α rb ) of ring‐beam protons, and wave normal angle on the excitation features of Martian ionospheric MS waves. We find the growth rates and frequency range of MS waves decrease by including O + and O 2 + ions but are insensitive to their relative concentrations. With increasing E rb or α rb , the growth rates of MS waves show a general dropping tendency. Meanwhile, their frequency and wavenumber range are almost unaffected by increasing E rb but shrink to a narrower range mainly distributed in high frequencies by increasing α rb . Unstable MS waves expand to a wider wavenumber range but shrink to a narrower frequency range as they become more oblique.