Figure 2. Altitude of the maximum electron density in the Mariner 9 radio occultation dataset, as a function of SZA. Red points were obtained during the dust storm, and black points outside the dust storm period. Despite their lower SZA, the peak altitudes are significantly higher during the dust storm. Figure elaborated from the Mariner 9 dataset MR9-M-RSS-5-ELEDENPROFILES-V1.0 (Withers & Joy, 2014) obtained from the Planetary Data System (PDS).