Logarithm of the energy flux ratio (upward / downward for electrons in the loss cone) for PJ1 to 9 North as a function of M-shell for the time intervals of this study. The gray range corresponds to that of the peak in energy flux of the 3-30 keV electrons. The symbols for M-shells polarward of that range are in blue and equatorward in orange. For most of the passes (except PJ9), there seems to be a sharp transition at the polarward edge of the shaded area. From Fig. 5 (and other figures in the supplemental information), that transition corresponds to the equatorward edge of the main oval. See also Fig 10 for the South passes.
