[P-EM12] Dynamics of the Inner Magnetospheric System

[PEM12-18] Probing inner magnetosphere dynamics and radial transport via observations of electron flux oscillations

★Invited Papers

*Theodore E Sarris¹ (1.Democritus University of Thrace)

Keywords:Radial transport, Electron flux oscillations, Phase space density, Radial diffusion

Relativistic electrons in the inner magnetosphere undergo dynamical variations due to acceleration, transport, and loss processes under various physical mechanisms. One of the prevalent mechanisms is radial diffusion, caused by the resonant interaction between energetic electrons and ultra-low frequency (ULF) waves. We discuss how an indication of this resonant interaction is the appearance of periodic flux oscillations. These oscillations are observed in the form of drift-periodic flux fluctuations and have distinct characteristics from the more commonly observed drift echoes following storm- or substorm-related energetic particle injections. The amplitudes of such flux oscillations is dependent on a number of parameters, such as the local phase space density gradients, the amplitude of ULF waves and the width of electron energy channels. In particular, the latter is a critical parameter affecting the observed amplitude of flux oscillations, with narrower energy channel widths enabling the observation of higher-amplitude flux oscillations; this potentially explains why such features were not observed regularly before the Van Allen Probes era, as previous spacecraft generally had lower energy resolution. We present simulations and observations demonstrating the dependence of the observed flux oscillations on various parameters and we discuss how such flux oscillations could be used as indicators of radial transport rates.