The magnetic structure of the subsolar MPB current layer from MAVEN observations: Implications for the Hall electric force

TL;DR

This study analyzes MAVEN spacecraft data to characterize the magnetic structure and current layer of Mars's subsolar MPB, revealing a sunward Hall electric force influencing solar wind ion deflection.

Contribution

It provides the first detailed local analysis of the MPB current layer at Mars, highlighting its structure, current density, and the resulting Hall electric force.

Findings

Detected a well-defined current layer within the MPB.

Estimated the current density and identified a sunward Hall electric force.

Found the MPB current layer thickness comparable to the upstream proton inertial length.

Abstract

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 and provide a local estimate of its current density which results in a sunward Hall electric 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.