Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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Long-Term Dropout of Relativistic Electrons in the Outer Radiation Belt During Two Sequential Geomagnetic Storms
Author | Wu, H.; Chen, T.; Kalegaev, V.; Panasyuk, M.; Vlasova, N.; Duan, S.; Zhang, X.; He, Z.; Luo, J.; Wang, C.; |
Keywords | Radiation belt; relativistic electron dropout; Geomagnetic storm; Van Allen Probes |
Abstract | On 31 January 2016, the flux of >2 MeV electrons observed by Geostationary Operational Environmental Satellite (GOES)-13 dropped to the background level during a minor storm main phase (−48 nT). Then, a second storm (−53 nT) occurred on 2 February; during the 3 days after its main phase, the flux remained at background level. Using data from various instruments on the GOES, Polar Operational Environmental Satellites (POES), Radiation Belt Storm Probes (RBSP), Meteor-M2, and Fengyun-series spacecraft, we study this long-term dropout of MeV electrons during two sequential storms of similar magnitude under lightly disturbed solar wind conditions. Observations from low-altitude satellites show that the fluxes decreased first at higher L-shells and then gradually propagated inward. Moreover, the fluxes were almost completely lost and dropped to the background level at L > 5, while the fluxes at 4 < L < 5 were partly lost, as observed by RBSP and low-altitude satellites. Finally, observations show that on 5 February, only the fluxes at L > 5.5 recovered, while the fluxes at 4 < L < 5 did not return to the prestorm levels. These observations indicate that the loss and recovery processes developed first at higher L-shells. Phase space density (PSD) analysis shows that radial outward diffusion was the main reason for the dropout at higher L-shells. Regarding electron enhancement, stronger inward diffusion was accompanied by ultra-low-frequency (ULF) wave activities at higher L-shells, and chorus waves observed at outer L-shells provided conditions for relativistic electron flux recovery to the prestorm levels. |
Year of Publication | 2020 |
Journal | Journal of Geophysical Research: Space Physics |
Volume | 125 |
Number of Pages | e2020JA028098 |
Section | |
Date Published | 10/2020 |
ISBN | |
URL | https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JA028098 |
DOI | https://doi.org/10.1029/2020JA028098 |