On the Formation of Phantom Electron Phase Space Density Peaks in Single Spacecraft Radiation Belt Data

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Abstract
Abstract This paper examines the rapid losses and acceleration of trapped relativistic and ultrarelativistic electron populations in the Van Allen radiation belt during the September 7-9, 2017, geomagnetic storm. By analyzing the dynamics of the last closed drift shell (LCDS) and the electron flux and phase space density (PSD), we show that the electron dropouts are consistent with magnetopause shadowing and outward radial diffusion to the compressed LCDS. During the recovery phase an in-bound pass of Van Allen Probe A shows an apparent local peak in PSD, but which does not exist. A careful analysis of the multipoint measurements by the Van Allen Probes reveals instead how the apparent PSD peak arises from aliasing monotonic PSD profiles which are rapidly increasing due to acceleration from very fast inwards radial diffusion. In the absence of such multi-satellite conjunctions during fast acceleration events, such peaks might otherwise be associated with local acceleration processes.
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Year of Publication
2021
Journal
Geophysical Research Letters
Volume
n/a
Number
Number of Pages
e2020GL092351
Date Published
05/2021
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL092351
DOI
https://doi.org/10.1029/2020GL092351