Quantifying Extremely Rapid Flux Enhancements of Radiation Belt Relativistic Electrons Associated With Radial Diffusion

Author
Keywords
Abstract
Previous studies have revealed a typical picture that seed electrons are transported inward under the drive of radial diffusion and then accelerated via chorus to relativistic energies. Here we show a potentially different process during the 2\textendash3 October 2013 storm when Van Allen Probes observed extremely rapid (by about 50 times in 2 h) flux enhancements of relativistic (1.8\textendash3.4 MeV) electrons but without distinct chorus at lower L-shells. Meanwhile, Time History of Events and Macroscale Interactions during Substorms satellites simultaneously measured enhanced chorus and fluxes of energetic (\~100\textendash300 keV) seed electrons at higher L-shells. Numerical calculations show that chorus can efficiently accelerate seed electrons at L \~ 8.3. Then radial diffusion further increased the phase space density of relativistic electrons throughout the outer radiation belts, with a remarkable agreement with the observation in magnitude and timescale. The current results provide a different physical scenario on the interplay between radial diffusion and local acceleration in outer radiation belt.
Year of Publication
2018
Journal
Geophysical Research Letters
Number of Pages
1262-1270
Date Published
02/2018
URL
http://onlinelibrary.wiley.com/doi/10.1002/2017GL076513/full
DOI
10.1002/grl.v45.310.1002/2017GL076513