Observation of Plasma Instability on the Dayside Region between Magnetosheath and Ionosphere of Mars

The interaction of the solar wind with the plasma envelope of planets without their own global magnetic field has a different character than does the corresponding process near the Earth due to the closer location of the bow shock to the planet’s surface. Similar processes and structures in the interaction of the solar wind with the plasma envelope of the planet can be found in both planets with a global magnetic field and without. In this paper, we analyze the observations of plasma structures found in the transition region between the ionosphere and magnetosheath, better known as the region of the induced magnetosphere, on the dayside of Mars based on the measurement data of a set of instruments for studying the characteristics of particles and fields of the spacecraft Mars Atmosphere and Volatile EvolutioN ( MAVEN ). The velocity of the observed plasma structures is calculated on the assumption that it coincides with the de Hoffmann–Teller velocity by minimizing the electric field in the moving coordinate frame. The hypothesis of the origin of these structures during the formation of vortices of the Kelvin–Helmholtz instability is tested by analyzing the velocity vectors of the H + , O + , and ions in different coordinate frames. An analysis of the scatter plots of projections of velocities depending on the density of the selected ionic component of the plasma is carried out. Based on the analysis results, it is shown that not all detection criteria are feasible in the case of the formation of vortices of the Kelvin–Helmholtz instability on Mars.