Evidence suggesting dumping of semitrapped electrons on the night side of the Earth

Processes leading to the production of energetic electrons and their precipitation into the auroral atmosphere are believed to take place in the earth's magnetosphere. Details as to how these electrons appear on and are removed from the magnetic lines linking the distant field and the auroral atmosphere are currently unknown, although all processes presumably result from interactions with the solar wind. The older interpretation of particle precipitation as simply dumping of the statically trapped radiation from the outer zone has largely given way to the concept of local acceleration for a number of compelling reasons [O'Brien, 1962; Winckler, 1962]. Nevertheless, the character of the precipitation may, in some instances, still be related to the local quasi-trapped reservoir of particles.