Solar cycle variation of outer belt electron dose at low-Earth orbit

The solar cycle dependence of dose rates in the low-altitude "horns" of the outer zone electron belt is examined using data from TSX5/CEASE (solar maximum epoch) and APEX/PASP+ (solar minimum epoch). It is found, after normalizing the dose rates to account for the different shielding geometries, that the ratio of PASP to CEASE dose rates is /spl sim/4 for L>4. This is contrary to the equal dose rates predicted by the NASA AE8MIN and AE8MAX models.