Energy Transport and Conversion Above a Bright Discrete Auroral Arc

Area of Science:

• Space Physics
• Magnetospheric Physics
• Plasma Physics

Background:

• Discrete auroral arcs are visual manifestations of energy transfer processes in Earth's magnetosphere.
• Understanding energy transport mechanisms is crucial for explaining particle acceleration phenomena.

Purpose of the Study:

• To investigate energy transport and conversion above a discrete auroral arc.
• To determine how energy converges into the acceleration region and powers electron energization.

Main Methods:

• Utilizing magnetically connected observations from the Reimei spacecraft.
• Combining in situ measurements of particle distributions and luminosity with imaging data.
• Analyzing transverse electromagnetic and kinetic energy fluxes along the spacecraft trajectory.

Main Results:

• Observed convergence of transverse energy fluxes into the acceleration region.
• Demonstrated facilitation of cross-field energy transport by vortex formation along the arc.
• Quantified energy inflow supporting local dissipation and electron acceleration.

Conclusions:

• Transverse and field-aligned energy flows into the arc locally support observed electron acceleration.
• Divergence of Poynting flux along and across the magnetic field drives field-aligned electron energization.