Variability of the outer radiation belt electron content

An integration of the electron density to obtain the total electron content over the entire volume of the outer radiation belt provides the ability to distinguish transport from acceleration and loss processes. We describe such a calculation based on differential energy spectra of electrons in the kinetic energy range of ~1 to 8~MeV measured on the Polar and SAMPEX satellites. Results show that the lower energy electrons are frequently resupplied so that the long term average radiation belt content is relatively steady. Higher energy electrons are supplied only by infrequent magnetic storm-time injections that are followed by long periods of steady decay to low levels of the radiation belt content. The data interpretation is complicated by frequent adiabatic variations at all energies. Methods for overcoming these and other difficulties are discussed.