Abstract
The plasma environment of Mars is highly influenced by crustal remnant
magnetism in the
planet. In this work, we do statistical analyses of MAVEN and MGS data
to study whether the
ionospheric plasma flow can move crustal magnetic field lines, by
advection. Due to the day-tonight
flow of the plasma, the magnetic field lines are expected to be dragged
away in anti-solar
direction, causing a shift between observed and modeled field. The
results show that a small shift
can be observed above weak anomalies on the Northern hemisphere, where
the ionospheric
plasma flow is less perturbed by strong magnetic fields. To investigate
the relative forces
between the moving plasma and the crustal field, we also calculated
dynamic, magnetic and
thermal pressures, since they are involved in the advection process. In
general, the dynamic
pressure is lower than the other two, but this does not mean advection
cannot occur, because the
process is not simply a pressure balance, but a diffusive process. The
calculation shows that, if
advection occurs on Mars, the speed at which the crustal field lines are
displaced is much smaller
than the speed of the ionospheric plasma flow.