Planetary distribution of the 27-day variation amplitudes of electron density in the E- and D-layers of the ionosphere

Quantitative estimation of the 27-day variation on electron density in the E and D-layers of the ionosphere in planetary scale is performed. It is shown that maximum of positive variations is observed at the magnetic equator, maximum of negative variations - in the regions with J approximately +- 80 deg magnetic dip. The 27-day variations of electron density have planetary character. Relative variations of the 27-day elcetron density variation at the magnetic equator constitutes ΔN/N approxiomately 26%, in the regions with J approximately +- 50 deg - ΔN/N approximately 15% and have the tendency towards the increase to magnetic poles (ΔN/N approximately 50%)