Open Magnetic Fields in the Martian Magnetosphere Revealing Dipole-like Intrinsic Magnetic Fields at Mars

Mars's magnetosphere is hybrid, having contributions from both an induced magnetosphere like Venus and the localized crustal magnetic fields. However, the planetary fields also include large-scale, more global components. In this study, we investigate their role in Mars's magnetospheric topological responses to the interplanetary magnetic field (IMF) clock angle using observations from the Mars Atmospheric Volatile and EvolutioN mission. We show that the large-scale planetary field has a dipole-like influence on the Mars global magnetosphere by examining the open field topology. We find that the dipole-like planetary field, as at Earth, results in a more open magnetosphere during southward IMF. The clock angle effects on the twisted magnetotail current sheet are similarly consistent with this analogy. It reinforces the idea that Mars's magnetosphere and solar wind interaction are more Earth-like than previously thought.

Automated summary

In this study, the authors investigate the role of large-scale planetary fields in Mars's magnetospheric responses to the interplanetary magnetic field. They find that the dipole-like planetary field has a similar influence on Mars's magnetosphere as it does on Earth, resulting in a more open magnetosphere during certain conditions.