The fine structure of the subsolar MPB current layer from MAVEN
observations: Implications for the Lorentz force.
We report on the local structure of the Martian subsolar Magnetic Pileup
Boundary (MPB) from minimum variance analysis of the magnetic field
measured by the Mars Atmosphere and Volatile EvolutioN (MAVEN)
spacecraft for six orbits. In particular, we detect a well defined
current layer within the MPB’s fine structure and provide a local
estimate of its current density which results in a sunward Lorentz
force. This force accounts for the deflection of the solar wind ions and
the acceleration of electrons which carry the interplanetary magnetic
field through the MPB into the Magnetic Pileup Region. We find that the
thickness of the MPB current layer is of the order of both the upstream
(magnetosheath) solar wind proton inertial length and convective
gyroradius. This study provides a high resolution view of one of the
components of the current system around Mars reported in recent works.