Global Energy Transport and Conversion in the Solar Wind-Mars Interaction: MAVEN Observations

The interaction between the solar wind and Mars plays a crucial role in driving atmospheric escape and shaping the Martian space environment. Despite its importance, the electromagnetic energy transport and conversion associated with this interaction remain poorly characterized. In this study, we construct global maps of electromagnetic energy transport and conversion at Mars using 9 years of magnetic field and plasma data from NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Our results reveal that the bow shock serves as an electromagnetic generator, converting the kinetic energy of the solar wind into electromagnetic energy. In contrast, the induced magnetotail acts as a load region, where electromagnetic energy is converted back into particle energy. The magnetosheath exhibits a spatially variable role: it functions as a generator in regions where the interplanetary magnetic field (IMF) is draped around the planet but transitions into a load region as the draped fields are diverted toward the magnetic poles. Planetary oxygen ions are persistently energized throughout the system, with particularly strong energization observed in the ion plume region. We also identify a pronounced hemispheric asymmetry in energy transport and conversion. While our qualitative results are robust, the quantitative analysis reveals an imbalance between the calculated energy transport and conversion terms. This discrepancy suggests that unresolved small-scale electric fields or currents and nonlinear processes may be missing from the present analysis, underscoring the need for future high-resolution, multi-point observations to better constrain the electromagnetic energy budget and enhance our understanding of the Martian space environment.