The heights of sporadic‐E layer simultaneously observed by the VHF radar and ionosondes in Chung‐Li

Abstract

Ionosondes and VHF radars have been employed to simultaneously observe the sporadic E (Es) layer. In previous studies, an absence of correlation was found between the height of field‐aligned irregularities (FAI) observed by the radars and the virtual height of the Es layer (h'Es) by their colocated ionosondes. A careful study shows that the low correlation results from the beam broadening effect of the ionosonde. In this paper, the investigation shows a better correlation between the heights of the FAI bottom‐side (h FAIb ) observed by the VHF radar and the h'Es by ionosondes in Chung‐Li. It is found that the h'Es is greater than the h FAIb by about 5–10 km. Meanwhile, we demonstrate that h'Es observed by two nearby ionosondes (and/or radars) can be employed to evaluate the velocity of waves in the Es layer.