Response of The Ionospheric E- Region Critical Frequency and Virtual Height to the Solar Cycle 22 over Baghdad


The aim of this study is to investigate the response of the Ionospheric E- regioncritical frequency foE and virtual height h’E parameters to the solar cycle 22 overBaghdad city (latitude 33.3˚N, longitude 44.4˚E). Both parameters display a highrelationship with the sunspot relative number within the ascending and descendingphases of the solar cycle. The E - region response to the solar activity is obviousaround noon, sunrise and sunset times. Moreover, the gap between local midafternoon,dawn and sunset values expands as solar activity rises. In the decliningphase, there is an aspect that results in a peak of disturbance. This portion may havelinked to coronal holes and resulted in high disturbance peak during 1992-1994. Theimpact of this portion is obvious in raising the values of foE, especially in 1993.