On the Particle Motion in Paleo‐Magnetosphere During the Geomagnetic Polarity Reversal

Abstract

Abstract During the Earth's magnetic reversal, the dipole component of the magnetic field weakens, and the non‐dipole component becomes dominant, resulting in a far more complex magnetospheric topology than that of a dipole. In this study, we used a particle tracing technique to investigate the motion of ions within an irregular magnetosphere during the Matuyama‐Brunhes magnetic polarity reversal. Compared to the scenario in which the geomagnetic field is dominated by a dipole component, earthward‐moving particles can be hardly “trapped” in the inner magnetosphere when the geomagnetic field experiences the polarity reversal, and particles can directly precipitate into the Earth's atmosphere on a global scale. It suggests that under an irregular magnetospheric configuration, the traditional trapped region of particles (e.g., radiation belt or ring current) no longer exists.

Keywords

• particle motion
• paleo‐magnetosphere
• geomagnetic reversal
• test‐particle simulation