Statistical properties of the radiation belt seed population. Issue 8 (16th August 2016)

• Record Type: Journal Article
• Authors: Boyd, A. J.; Spence, H. E.; Huang, C.‐L.; Reeves, G. D.; Baker, D. N.; Turner, D. L.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.; Shprits, Y. Y.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 8(2016:Aug.)
• Page Start: 7636
• Page End: 7646
• Publication Date: 2016-08-16
• Subjects: radiation belt -- seed population -- phase space density; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA022652
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We present a statistical analysis of phase space density data from the first 26 months of the Van Allen Probes mission. In particular, we investigate the relationship between the tens and hundreds of keV seed electrons and >1 MeV core radiation belt electron population. Using a cross‐correlation analysis, we find that the seed and core populations are well correlated with a coefficient of ≈0.73 with a time lag of 10–15 h. We present evidence of a seed population threshold that is necessary for subsequent acceleration. The depth of penetration of the seed population determines the inner boundary of the acceleration process. However, we show that an enhanced seed population alone is not enough to produce acceleration in the higher energies, implying that the seed population of hundreds of keV electrons is only one of several conditions required for MeV electron radiation belt acceleration. Key Points: The seed population is strongly correlated with the core radiation belt population The strongest correlation occurs at a 10–15 h time lag The seed population is subject to a threshold limit