Ion composition of the upper ionospheres of Mars and Venus and of the ion outflow

In this study we investigate the ion composition in the upper ionosphere of Mars and Venus and of the ionospheric outflow. We do this using observations from the ASPERA-3 and STATIC experiments on board Mars Express and MAVEN, respectively, and the ASPERA-4 experiment on board Venus Express. By applying a superposed epoch analysis, we will take a look at the statistical properties of ion distributions, and especially the minor ion populations, and their ratios. We take advantage of the long term data from Mars Express and Venus Express and also look at the ion dependence on solar EUV intensity. For Mars this can be compared with the more recent observations by the MAVEN mission. These results will help to constrain ionospheric models for Mars and Venus and may give clues to the importance and efficiency of different ion escape mechanisms.