Critical frequency seasonal variability in ionosphere E region during 22 minimum solar cycle phase at Ouagadougou station

Abstract

Ionosphere is the part of atmosphere region laying from 50 km up to 1000 km. This layer contains numerous of particles among which we have N2 and O2. Interactions between X-rays and ultraviolets coming from the sun and the particles in ionosphere layer cause ionization of these particles. The major ions in ionosphere are NO+, N2+, O2+, O+, O2-. At daytime, under low latitudes, ionosphere layer shows different layers (D, E, F1, F2). D and E layers combine at nighttime and sometimes disappear. The density of ionization of a layer gives it the capacity to reflect radio waves. Ionosphere layer is electrically neutral and moves like a plasma. Critical frequency is given by the maximum density value below which radio waves reflect when they hit the layer as an obstacle. This study deals with critical frequency of ionosphere E layer (foE) at 22 minimum solar cycle phase at Ouagadougou station. foE seasonal variability for characteristic month of each season is calculated. Quiet days are considered in this study. The study also uses International Reference Ionosphere (IRI) model for foE modeling.Key words: Ionosphere, E-layer, critical frequency, solar cycle, quiet days, IRI model.