Abstract
Abstract
On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (>2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased >90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere. Key Points Substorm dynamics are important for highly relativistic electron energization Cold plasma preconditioning is significant for rapid relativistic energization Relativistic / highly relativistic electron energization can occur in < 5 hrs.
Department
Physics
Publication Date
1-2014
Journal Title
Geophysical Research Letters
Publisher
American Geophysical Union Publications
Digital Object Identifier (DOI)
10.1002/2013GL058438
Document Type
Article
Recommended Citation
Foster, J. C., et al. (2014), Prompt ener-gization of relativistic and highly rela-tivistic electrons during a substorminterval: Van Allen Probes observations,Geophys. Res. Lett., 41,20–25,doi:10.1002/2013GL058438.
Rights
©2013. American Geophysical Union. All Rights Reserved.