The Response of an Ionosphere to Changes in the solar F10.7 flux: Comparison of Venus, Earth, and Mars
Paul Withers and Michael Mendillo

There are many similarities between the terrestrial E region and the ionospheres of Venus and Mars. All are dominated by photochemical, not transport, processes. The dissociative recombination of molecular oxygen ions is an important loss mechanism for all three regions. Various workers have studied how ionospheric properties, such as the peak electron density, in these regions respond to changes in solar flux, especially as represented by the F10.7 index. Timescales of interest include the solar cycle, the solar rotation period, and shorter periods, such as one day. We shall discuss the many parameterizations of such responses that have been published and examine their consistencies with known photochemical processes.