Diffusion and injections in the radiation belts: L shell coupling

The outer zone of the electron radiation belts is divided in three main regions in L shell: the P0 region (L=3-4 approx.), the P1 region (L=4-7) or heart of the outer zone, and the P2 region (L>7) which is related to the cusp and plasma sheet [Vassiliadis et al., JGR 2002; Phys. Plasmas, 2003]. We measure the correlation between fluxes at adjacent and nearby L shells. We use autoregressive models to account for the coupling. The correlation values and the model coefficients are interpreted in terms of slow diffusion (time scales >=2 days) and rapid injections (<1 day). We parametrize the response by the electron energy measured by SAMPEX/PET fluxes at 2-6 MeV and EXOS-C/HEP at 0.19-3.5 MeV.