F3 layer development during quiet and disturbed periods as observed at conjugate locations in Brazil: The role of the meridional wind

Abstract

AbstractIn 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 F3 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 F3 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 F3 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 F3 layer occurrence.