Electromagnetic Structures and Particle Acceleration in Earth's Radiation Belts

Observations from NASA's Van Allen Probes have revealed the persistence of highly structured electromagnetic fields in the inner magnetosphere during geomagnetically active periods. In this presentation we decompose these structures into the fundamental low frequency plasma modes and show how these modes are modified by the large-scale inhomogeneity of the geomagnetic field and plasma through this region of space. This analysis identifies eigen-modes of the geomagnetic field that are extremely extended along the field but have transverse scales comparable to average ion-gyro radii. These features appear as part of a spectrum of filamentary currents and vortical flow structures generated through this region of space in association with plasma injections from the outer magnetosphere.