Data-Model Comparisons of Planetary Ions at Mars

We present a Mars Atmospheric and Volatile EvolutioN (MAVEN) data-model comparison to better constrain the response of Mars’ atmosphere to changes in the interplanetary magnetic field (IMF) configuration, specifically with how the IMF influences the escape of the atmosphere. Because Mars lacks a dipole magnetic field, the solar wind directly interacts with the upper neutral atmosphere to create ‘pick-up’ ions. The pick up ions can subsequently escape to space, with a spatial dependence on the IMF configuration. We will present global maps of escaping O+ during different solar cycle phases for multiple IMF conditions using a magnetohydrodynamic and test particle simulation. We will compare these to the relevant MAVEN datasets and examine how the different IMF configurations could influence the escape rate from Mars’ atmosphere. Using the models, we will also address the role of the solar cycle and crustal field orientation.