Figure 5From: Global distribution of the migrating terdiurnal tide seen in sporadic E occurrence frequencies obtained from GPS radio occultationsLatitude-time plot of the normalised amplitude of the 8-h oscillation at approximately 90/110 km (left/right panel). Shown are 6-year averages, based on 3-monthly mean zonal means derived from FORMOSAT-3/COSMIC satellite measurements from December 2006 to November 2012. Reddish areas show regions with an occurrence frequency of sporadic E layers >30/1,000.Back to article page