| Autor: |
Wang, Xu1,2 (AUTHOR), Dai, Lei1 (AUTHOR) ldai@spaceweather.ac.cn, Yong, Ren1 (AUTHOR), Xiong, Senlin1,2,3 (AUTHOR), Wang, Chi1 (AUTHOR) |
| Předmět: |
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| Zdroj: |
Journal of Geophysical Research. Space Physics. Nov2024, Vol. 129 Issue 11, p1-15. 15p. |
| Abstrakt: |
Earth's outer radiation belts are highly dynamic during geomagnetic storms. Using electron flux data from 226 keV to 2.6 MeV measured by the Van Allen Probes, we statistically analyzed the peak flux position Lpeak $\left({L}_{\mathit{peak}}\right)$ and inner boundary position Lmin $\left({L}_{\min }\right)$ of the outer radiation belt across different storm phases: pre‐storm quiet time, main phase, early recovery phase, and later recovery phase. This analysis covered 196 geomagnetic storm events from October 2012 to September 2019. Our results indicate that: (a) During the pre‐storm, Lpeak ${L}_{\mathit{peak}}$ decreases with increasing energy. From the pre‐storm to the early recovery phase, Lpeak ${L}_{\mathit{peak}}$ shifts inward for energies below 1 MeV and outward for energies above 1 MeV. For all energies, Lpeak ${L}_{\mathit{peak}}$ converges to approximately L = ∼ ${\sim} $4.3–4.6 in the early recovery phase. (b) Below approximately 1 MeV, Lmin ${L}_{\min }$ generally move inward from the main phase to the early recovery phase. Above 1 MeV, Lmin ${L}_{\min }$ remains nearly unchanged across different storm phases. (c) The half‐width (Lpeak ${L}_{\mathit{peak}}$−Lmin ${L}_{\min }$) of the outer belt decreases during the main phase for energies below 1 MeV and increases during the recovery phase for energies above 1.5 MeV. (d) In the early recovery phase, Lpeak ${L}_{\mathit{peak}}$ and Lmin ${L}_{\min }$ at 593–742 keV show a moderate correlation with storm intensity (∣ $\vert $CC∣∼ $\vert \sim $ 0.7–0.8), while Lpeak ${L}_{\mathit{peak}}$ and Lmin ${L}_{\min }$ at energies greater than 1.1 MeV exhibit low correlations (∣ $\vert $CC∣≤∼ $\vert \le \sim $0.4) during each phase. These results confirm the complex, energy‐dependent morphology of the outer radiation belt throughout geomagnetic storm phases. Key Points: The energy‐dependent morphology of the outer radiation belt over storm phase is studied statistically in Van Allen Probe eraThe peak flux position of the outer belt converges to L = ∼4.3–4.6 for all energies in early recovery phaseThe inner boundary of the outer belt for > ${ >} $1 MeV electrons changes very little (≤ ${\le} $0.1 RE ${R}_{E}$) over storm time [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
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