Fig. 9
From: Recovery and validation of Mars ionospheric electron density profiles from Mariner 9
Top. Inferred subsolar M2 peak electron density as a function of adjusted F 10.7 (values in solar flux units). Crosses and diamonds indicate occultations from the primary and extended missions, respectively. The solid line is a fit to the primary mission data, excluding the anomalous result from orbit 4 (square symbol). Bottom. As top panel, but for subsolar M1 peak electron density. The anomalous result from orbit 4, which is excluded from the fit, is below the density range of this plot