Fig. 1From: Effects of the postsunset vertical plasma drift on the generation of equatorial spread FExample of equatorial ionospheric irregularities measured by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite on 17 October 2011. Figure 1 a–d show the C/NOFS orbit, the ion density, the standard deviation of ion density variations (σ), and the ion density perturbations (ΔN), respectivelyBack to article page