High-latitude plasma transport through the Martian tail: polar wind

Abstract

Flux, density, velocity, and temperature (parallel and perpendicular) are calculated by using the polar wind acceleration process in the dayside and nightside ion exosphere of Mars at exospheric plasma temperatures 1000 K, 1500 K, and 2000 K. The results are compared with the measurements made by the solar wind plasma instrument (TAUS) and automatic space plasma experiment with a rotating analyzer (ASPERA) experiments in the magnetotail of Mars. For these calculations the ionospheric plasma is transported into the Martian tail along the magnetic field line in the presence of charge separation electric fields, which are calculated by using a quasi-neutrality condition such that both flux and density of ions are equal at every point in the exosphere to flux and density of electrons. It has been found that the ions O⁺, O 2 ⁺ , and NO⁺ are present in the distant tail at 2000 K. The ion CO 2 ⁺ seems to be absent at high altitude because of the polar wind acceleration mechanism. Among these ions, O⁺ is the dominant species in the Martian tail. The exospheric plasma temperature is the most important parameter in the polar ion exosphere. As it increases from 1000 K to 2000 K, the results are found to be changed by several orders of magnitude.