The quadrupole as a source of energetic particles: III. Outer radiation belt and MeV electrons

The observation that high speed solar wind streams are correlated with outer radiation belt electrons requires a transducer to convert this mechanical energy to hot electrons. We hypothesize that the high latitude cusp is the ideal location for this acceleration region. We support this hypothesis with two arguments: a forward model to show that the cusp can theoretically accelerate electrons to MeV energies which then are transported to the radiation belts; and, a backward model that deduces a cusp source based on empirical properties of the radiation belt MeV electrons. Accordingly, in the first half we apply the trapping properties of the static equinoctal cusp to deduce the dynamical response of interplanetary transients; in the second half we analyze several peculiar statistics of MeV electron correlations with solar wind as the response of a non-linear, multi-parameter dependence on the solar wind driver. Our model would permit the formulation of more physically accurate MeV electron predictors, which we demonstrate by connecting physical explanations to several empirical predictors recently published.