A New look at the ionosphere of Jupiter in light of the UVS occultation results

Abstract

Simple photochemical models cannot reconcile Jupiter's ionospheric electron density profiles with the observed neutral atmosphere. The location of the peak electron density predicted when the neutral atmosphere determined by the Voyager Ultraviolet Spectrometer is combined with simple models falls about 1000km lower than the peak determined by radio occultation. The locations and magnitudes of the peaks in electron density can be accounted for by including the effects of vertical transport of ions in the ionospheric models. This vertical transport may be induced by meridional winds in the neutral atmosphere or external electric fields. It is probable that precipitating particles and an altitude-variable H 2 vibrational temperature play important roles in determining the character of the ionośphere. In view of the complex relationship between the ionosphere and neutral atmosphere, an attempt to infer one from the other cannot succeed. However, combining independent information on the two leads to new insights into the coupling of the neutral atmosphere, the ionosphere and the magnetosphere.