On the relationship between electron flux oscillations and ULF wave‐driven radial transport

The objective of this study is to investigate the relationship between the levels of electron flux oscillations and radial diffusion for different Phase Space Density gradients, through observation and particle‐tracing simulations under the effect of model ultralow frequency fluctuations. This investigation aims to demonstrate that electron flux oscillation is associated with and could be used as an indicator of ongoing radial diffusion. To this direction, flux oscillations are observed through the Van Allen Probes' Magnetic Electron Ion Spectrometer (MagEIS) subsequently, flux oscillations are produced in a particle‐tracing model that simulates radial diffusion by using model magnetic and electric field fluctuations that are approximating measured magnetic and electric field fluctuations as recorded by the Van Allen Probes' Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) and Electric Fields and Waves (EFW) instruments, respectively. The flux oscillation amplitudes are then correlated with Phase Space Density gradients in the magnetosphere and with the ongoing radial diffusion process. Plain Language Summary The objective of this study is to investigate the relationship between the levels of electron flux oscillations and radial diffusion, through particle‐tracing simulations under the effect of model ultralow frequency fluctuations. To this direction, flux oscillations are observed through the energetic particle detector Magnetic Electron Ion Spectrometer on board the Van Allen Probes—a twin spacecraft mission to study the radiation belts. Subsequently, flux oscillations are reproduced in a particle‐tracing model that simulates radial diffusion by using analytic random magnetic and electric field fluctuations. These model fluctuations are constructed so as to match measurements of magnetic and electric field fluctuations as recorded by the Van Allen Probes' Electric and Magnetic Field Instrument Suite and Integrated Science and Electric Fields and Waves instruments, respectively. The flux oscillation amplitudes are then correlated with the ongoing radial diffusion process. Whereas up to now electric and magnetic field oscillations were used to estimate the levels of radial diffusion, through this comparison it is demonstrated for the first time that the amplitude of electron flux oscillations is also associated with and could be used as an indicator of ongoing radial diffusion. Key Points Investigation of the relationship bet