Auroral Effects and Excess Energy Electrons

Abstract

AURORAL displays are usually attributed to increased leakage of electrons from the outer radiation belt. The mechanism responsible for this increased leakage is not yet understood, but the leakage is known to occur following the arrival of corpuscular radiation from the Sun. The time delay between solar eruptions and the onset of auroral phenomena shows that any solar electrons involved must have energies below 100 eV. Because, on the other hand, auroral electrons typically have energies in the range of several tens of keV, an electron acceleration mechanism must exist, presumably within the radiation belt. The purpose of this communication is to point out similarities between auroral effects and laboratory observations of electron leakage from a magnetic mirror, accompanied by electron acceleration, and to suggest that the same basic mechanism may play a part in both cases.