TY  - JOUR
A1  - Boyd, A. J.
A1  - Spence, Harlan E.
A1  - Huang, Chia-Lin
A1  - Reeves, Geoffrey D.
A1  - Baker, Daniel N.
A1  - Turner, D. L.
A1  - Claudepierre, Seth G.
A1  - Fennell, Joseph F.
A1  - Blake, J. Bernard
A1  - Shprits, Yuri Y.
T1  - Statistical properties of the radiation belt seed population
JF  - Journal of geophysical research : Space physics
N2  - 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 approximate to 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.
Y1  - 2016
U6  - https://doi.org/10.1002/2016JA022652
SN  - 2169-9380
SN  - 2169-9402
VL  - 121
SP  - 7636
EP  - 7646
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kim, Kyung-Chan
A1  - Shprits, Yuri Y.
A1  - Blake, J. Bernard
T1  - Fast injection of the relativistic electrons into the inner zone and the formation of the split-zone structure during the Bastille Day storm in July 2000
JF  - Journal of geophysical research : Space physics
N2  - During the July 2000 geomagnetic storm, known as the Bastille Day storm, Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX)/Heavy Ion Large Telescope (HILT) observed a strong injection of similar to 1MeV electrons into the slot region (L similar to 2.5) during the storm main phase. Then, during the following month, electrons were clearly seen diffusing inward down to L=2 and forming a pronounced split structure encompassing a narrow, newly formed slot region around L=3. SAMPEX observations are first compared with electron and proton observations on HEO-3 and NOAA-15 to validate that the observed unusual dynamics was not caused by proton contamination of the SAMPEX instrument. The time-dependent 3-D Versatile Electron Radiation Belt (VERB) simulation of 1MeV electron flux evolution is compared with the SAMPEX/HILT observations. The results show that the VERB code predicts overall time evolution of the observed split structure. The simulated split structure is produced by pitch angle scattering into the Earth atmosphere of similar to 1MeV electrons by plasmaspheric hiss.
KW  - inner radiation zone and slot region
KW  - Bastille Day geomagnetic storm
KW  - 3-D diffusion simulation
KW  - plasmaspheric hiss
Y1  - 2016
U6  - https://doi.org/10.1002/2015JA022072
SN  - 2169-9380
SN  - 2169-9402
VL  - 121
SP  - 8329
EP  - 8342
PB  - American Geophysical Union
CY  - Washington
ER  -