Further Study on Possible Effects of the Dynamo-Electric Field on Electrons Trapped in the Magnetosphere

Abstract

The electrostatic field communicated from the dynamo region (the E region) into the magnetosphere will affect the motion of the trapped electrons. The case of electrons with energy ranging from 300eV to 30keV is treated. The electron orbit between two conjugate mirror points shifts earthward (inward) during night and outward during daytime. At the same time the mirror points shifts downwards and equatorwards (or upwards and polewards) during night (or daytime). The integrated effect on the apex height of an orbit and its diurnal variation are given.
The number of inelastic collisions of an electron is calculated and the effective lifetime of a trapped electron is estimated. By the use of this result a possibility is studied whether the trapped electrons, coming down to the mirror point as low as 300-500km, can be the principal cause of ionization of the F region during night.