Upper ionosphere of mars during solar quiet and disturbed conditions

Abstract

In this chapter, we have described upper and lower ionospheric measurements, which have been obtained from radio occultation experiment onboard Mariners 6, 7 and 9; Mars 4 and 5; Viking 1 and 2; Mars Global Surveyor; and Mars Express. The ionisation sources like solar EUV, X-ray and particle radiations have been discussed. Observations on the upper ionosphere of Mars during disturbances like aurorae, solar flares, solar energetic particles and coronal mass ejections are also described. The understanding of complex behaviour of Martian ionosphere requires a balanced effort in the area of theoretical modelling. Therefore, we have also reported modelling of the upper ionosphere of Mars during quiet and disturbed conditions. At present measurements on the ionosphere of Mars are limited to middle- and high-latitude region. The low-latitude ionosphere ofMars is not observed. The physics of the low-latitude ionosphere could be very different from middle- and high-latitude ionosphere. Therefore, it is necessary to look for opportunities for obtaining observations at low-latitude region.