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On the Formation of Phantom Electron Phase Space Density Peaks in Single Spacecraft Radiation Belt Data
Author(s) -
Olifer L.,
Mann I. R.,
Ozeke L. G.,
Morley S. K.,
Louis H. L.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl092351
Subject(s) - physics , acceleration , van allen radiation belt , van allen probes , computational physics , electron , diffusion , phase (matter) , spacecraft , electron density , radiation , plasmasphere , magnetosphere , astrophysics , geophysics , magnetic field , optics , classical mechanics , astronomy , quantum mechanics , thermodynamics
This study 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, which does not exist in reality. 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 multisatellite conjunctions during fast acceleration events, such peaks might otherwise be associated with local acceleration processes.