Figure 3From: Global distribution of the migrating terdiurnal tide seen in sporadic E occurrence frequencies obtained from GPS radio occultationsExample of occurrence frequencies (1/1,000) of sporadic E layers (left) and the corresponding residuals (right). The residuals are the occurrence frequencies after the mean, 12- and 24-h oscillations were subtracted. Shown are 3-monthly mean zonal means of October (September to November) 2010, covering the latitudes from 43° to 63° N.Back to article page