Banana Current in the Inner Magnetosphere Observed by Van Allen Probes

Abstract

The current system in the Earth's magnetosphere plays an essential role in the transport of mass and energy in the space (Davenport, 1996;Olson, 1984). The basic structure and dynamics of the primary electric current systems (e.g., magnetopause current, magnetotail current, ring current, and field-aligned current) determine the coupling between different regions of the magnetosphere (Ganushkina et al., 2018). The ring current flowing around the Earth is one of the most important space currents in the inner magnetosphere and is usually referred as the westward ring current since the ions drift westward and electrons drift eastward. During geomagnetic storms, the ring current exhibits a significant asymmetry at different magnetic local times (MLTs), mainly manifested by the dawn-dusk asymmetry (