The particle data from NOAA-17 and NOAA-16 spacecraft. In panels a and b, the solid lines show precipitating electron fluxes from four low energy channels in four different colors detected by the 0^∘ TED detector, while the dashed lines show precipitating electron fluxes at 30^∘ from local zenith. Panels c and d show energy fluxes of 0.1–20 keV electrons. Panels e and f show the fluxes of energetic electrons at 3 energy channels from MEPED: the solid lines present the precipitating electrons (10^∘ ), and the dashed lines present the trapped electrons (80°). The vertical dashed cyan lines indicate the boundaries of energetic electrons, which is taken as a proxy for the OCB.