F sub(3) layer development during quiet and disturbed periods as observed at conjugate locations in Brazil: The role of the meridional wind

• Published in: Journal of geophysical research. Space physics 2017-02, Vol.122 (2), p.2361-2373
• Main Authors: Batista, Inez S, Candido, CMN, Souza, J R, Abdu, MA, Araujo, R C, Resende, LCA, Santos, A M
• Format: Article
• Language: English
• Subjects: F region; Formations; Geomagnetism; Mathematical models; Parameters; Solstices; Stations; Wind power generation
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1002/2016JA023724

In this work we use ionospheric data from two low-latitude stations located north and south of the geomagnetic equator, at approximately the same magnetic longitude, in order to study the occurrence of the F sub(3) layer. The location of the stations being at almost geomagnetically conjugate points is such that the effects of the electric field/vertical plasma drift and diffusion will be almost symmetric around the magnetic equator. Under this configuration it is possible to deduce the effect of meridional wind in the F sub(3) layer occurrence. Our results show that during the December solstice the layer will be present at the Southern Hemisphere (SH) location in 97% of the days and in the Northern Hemisphere (NH) location in only 4% of the days. In the June solstice the situation is reversed with the occurrence in the NH being 82% and 16% in the SH. For the March equinox the occurrence is low at both locations (4% in NH and 7% in SH), being mainly present during magnetically disturbed periods. The analysis of the effective meridional wind based on the Horizontal Wind Model and on the asymmetry of the F layer peak height observed at the two locations confirms the ubiquitous role of the wind in the F sub(3) layer formation and/or persistence during both quiet and disturbed periods. The B0 parameter, that is a measure of the thickness of the bottomside F region profile, revealed to be a good proxy for the F sub(3) layer occurrence. Key Points * The B0 thickness parameter is a good proxy to describe the F sub(3) occurrence at the low-latitude locations * Effective meridional wind toward the equator is a necessary condition for F sub(3) layer formation during quiet periods * During disturbed periods the F sub(3) layer will last longer at the hemisphere under the condition of equatorward effective meridional wind