The Global Characteristics of Electrons Near the Inner Edge of the Inner Radiation Belt

• Published in: Journal of geophysical research. Space physics 2024-10, Vol.129 (10), p.n/a
• Main Authors: Walton, S. D., Lejosne, S., Claudepierre, S. G.
• Format: Article
• Language: English
• Subjects: Dynamic pressure; Earth magnetosphere; Electron flux; Electron flux measurements; Inner radiation belt; magnetosphere; Outer radiation belt; Radiation; Radiation belts; Radiation counters; Solar wind; Solar wind speed; Spacecraft; Statistics; Trapped electrons; Van Allen probes; Wind speed
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2024JA032883

Energetic electrons around the inner edge of the inner radiation belt (L≲ $\lesssim $1.3) have not been studied to the extent of the rest of the inner belt and certainly not to that of the outer radiation belt. Yet, the behavior of electrons at the inner edge of the inner belt could improve our understanding of important dynamics deep within Earth's magnetosphere. Previous work has analyzed these electrons during either isolated events or via significantly limited statistical studies, and it remains unclear what the particular drivers of electron flux enhancements in this region may be. Here, we present a broad statistical study of electrons around the inner edge of the inner radiation belt, utilizing the 7‐year data set of the MagEIS particle detectors aboard both Van Allen Probes spacecraft. Moreover, we separate electron flux measurements into stably trapped and quasi‐trapped electrons and directly compare their behavior. We find both populations to be variable in L and energy, as well as showing a clear magnetic local time (MLT) asymmetry. Potential drivers are also explored, where we demonstrate an association between increased electron fluxes in this region and heightened solar wind speed, Sym‐H, dynamic pressure, southward IMF Bz ${\mathrm{B}}_{z}$ and most prominently with the AU and AL indices. Key Points The global behavior of electrons near the inner edge of the inner radiation belt are statistically analyzed Stably and quasi‐trapped electrons are dependent on L and MLT, and are particularly responsive to AU, AL, VSW ${\mathrm{V}}_{SW}$ and Sym‐H ≳ $\gtrsim $70 keV quasi‐trapped electron fluxes appear most variable and sensitive to geomagnetic activity