Statistical study of the storm time radiation belt evolution during Van Allen Probes era: CME- versus CIR-driven storms

The Van Allen Probes twin spacecraft, launched on 30 August 2012, orbit near the equatorial plane and across a wide range of L* with apogee at 5.8R(E) and perigee at 620 km. Electron data from Van Allen Probes MagEIS and REPT instruments have been binned every 6h at L* = 3 (defined as 2.5 < L* < 3.5), 4 (3.5 < L* < 4.5), 5 (4.5 < L* < 5.5).

The superposed epoch analysis shows that (1) CME storms induce more electron flux enhancement at L* = 3 for energy channels below 1MeV than CIR storms; (2) CME storms induce more electron flux enhancement at L* = 4 and 5 in the energy channels above 1MeV than CIR storms; (3) CIR storms induce more electron flux enhancement at L* = 4 and 5 in the energy channels below 1MeV than CME storms; (4) intense CME induce more than 50 times flux enhancement for the energy channel around 400keV at L* = 3; (5) intense CIR induce more than 50 times flux enhancement for the energy channel around 200 keV at L* = 4.