FoF2 Diurnal Variability at African Equatorial Stations: Dip Equator Secular Displacement Effect

Doua A Gnabahou,Frédéric Ouattara,Emmanuel Nanéma,François Zougmoré

doi:10.4236/ijg.2013.48108

Doua A Gnabahou, Frédéric Ouattara + Show 2 more

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https://doi.org/10.4236/ijg.2013.48108

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Abstract

The paper goal is to analyze the variability of foF2 at African equatorial stations and the effect of dip angle on this variability. The gap between the dip angle of Dakar and Ouagadougou is superior to that between Djibouti and Ouagadougou. The trend of the dip angle at Ouagadougou and Dakar decreases while that of Djibouti increases. The relative position of the station with respect to the equator and the trend sign explains the difference observed in foF2 variability at Dakar station and at the two other stations. At Djibouti and Ouagadougou, foF2 exhibits noon bite out profile during all solar cycle phases while at Dakar observed profile is dome or plateau during the maximum and the predominance afternoon peak for the other solar cycle phases.

Highlights

Equatorial ionosphere that of African stations has been intensively investigated during the last decade (e.g. [1] Rishbeth and Mendillo; [2] Pancheva et al.; [3] Lei et al.; [4] Ataç et al.; [5] Ouattara et al.; [6] Obrou et al.; [7] Özgüç et al.; [8] Pham et al.; [9] Ouattara and Zerbo; [10] Ouattara and Amory Mazaudier; [11] Gnabahou et al.; [12] Ouattara)
The analysis of foF2 diurnal variation at Djibouti station ([27] Gnabahou and Ouattara) and that at Ouagadougou station ([10] Ouattara and Amory Mazaudier) show some similitude, and this induces that the foF2 variations at this African sector are due to longitude effect
As these African equatorial stations (Ouagadougou, Dakar and Djibouti), do not have the same dip angle, the topic of the present study is to analyze the effect of the dip equator secular displacement on foF2 variability at these African equatorial stations

Summary

Introduction

Equatorial ionosphere that of African stations has been intensively investigated during the last decade (e.g. [1] Rishbeth and Mendillo; [2] Pancheva et al.; [3] Lei et al.; [4] Ataç et al.; [5] Ouattara et al.; [6] Obrou et al.; [7] Özgüç et al.; [8] Pham et al.; [9] Ouattara and Zerbo; [10] Ouattara and Amory Mazaudier; [11] Gnabahou et al.; [12] Ouattara). The analysis of foF2 diurnal variation at Djibouti station ([27] Gnabahou and Ouattara) and that at Ouagadougou station ([10] Ouattara and Amory Mazaudier) show some similitude, and this induces that the foF2 variations at this African sector are due to longitude effect. As these African equatorial stations (Ouagadougou, Dakar and Djibouti), do not have the same dip angle, the topic of the present study is to analyze the effect of the dip equator secular displacement on foF2 variability at these African equatorial stations. For this reason the present work takes into account the effect of solar cycle phases

Methods

Results

Conclusion