On the sources of the night side ionosphere of Venus

Abstract

A general description of the characteristics of the night side ionosphere of Venus and plasma and magnetic environment in the near wake is presented. It is suggested that the variable character of the night side ionosphere should result, in part, from asymmetric conditions and time-dependent variations of the viscous penetration of the ionosheath flow into, the umbra, downstream from the planetary terminator. In addition to induction effects, the presence of magnetic fluxes associated with the intruding solar wind plasma should also contribute to explain the observed dependence of the magnetic geometry of the near wake on the interplanetary magnetic field.