Magnetic Reconnection in the Ionosphere of Mars: The Role of Collisions

Abstract

This paper evaluates the role of magnetic reconnection in the dayside ionosphere of Mars in the collisional regime and presents some relevant data from the MAVEN (Mars Atmosphere and Volatile EvolutioN) mission. Magnetic reconnection is an important process operating in the solar corona, planetary magnetospheres, and astrophysical plasmas, but most of the literature focuses on collision-less plasmas. However, at Mars the reconnection should often occur in regions where collisions are important. Mars does not have a large-scale global magnetic field; however, Mars has locally large magnetic fields associated with remnant crustal magnetization, particularly in the highland regions of the southern hemisphere. The crustal fields provide a “target’ for reconnection both in the ionosphere and in the magnetotail of Mars. The current paper emphasizes the dayside ionosphere. Magnetic reconnection is associated with topological changes in the magnetic field and is also a source of energy for the plasma, and can thus affect the ionospheric dynamics and ion loss at Mars. Both theoretical concepts and MAVEN particle and field data from several instruments are considered in this paper. The spacecraft data is contained in the attached Excel file and was used for the J. Geophysical Research paper (elsewhere in KU Scholarworks). Excel figures for most of the key paper figures can also be found in this Excel filed.