Irregular Phenomena in Magnetically Conjugate Regions of the F2 Layer of the Ionosphere

Resumo

The paper focuses on the behavior of relative variations in the critical frequency of the F2 layer of the ionosphere δfoF2 in magnetically conjugate regions under quiet and disturbed conditions. Comparison of changes in δfoF2 over time shows that the electron density level at stations in both hemispheres is about the same. The coupling of conjugate regions and the correlation of δfoF2 variations increase noticeably during ionospheric storms. In addition, the predawn effect in foF2 variations is investigated, which is caused by sunrise at the magnetically conjugate point. Statistics of the effect are presented for a month in winter. Examples of δfoF2 variations at the magnetically conjugate point during solar eclipses are given.