Alteration of crustal magnetic fields at Mars by currents induced by the solar wind interaction

Abstract:

Crustal magnetic fields were first discovered at Mars by the Mars Global Surveyor (MGS) mission (Acuña et al., 1998). Since then, there have been several crustal field models and maps produced, as well as many missions to Mars to better study the crustal magnetic fields. The crustal magnetic fields are thought to influence ion loss from the planet, so having a precise understanding of the structure of these fields is vital. The Mars Atmospheric and Volatile EvolutioN (MAVEN) explorer is yet another mission to the red planet, and its magnetometer (MAG) instrument has been returning interesting data on both induced and crustal magnetic fields. We compare MAG data with magnetic fields from crustal field models, like the M14 model (Morschhauser et al., 2014). In particular, we check how well the fields on the dayside compare with the models as opposed nightside. We expect greater data-model discrepancies on the dayside, where induced fields are thought to be more important. These comparisons can be done over multiple altitudes, and map “slices” can be produced at these multiple altitudes. The discrepancies provide information on the currents induced in the ionosphere by the solar wind.