Abstract
The change that takes place with the sunspot cycle of distortional characteristics in the daily variation of the F2-region on the magnetic equator is investigated herewith using Huancayo data during about one sunspot cycle. It is found that the type of the daily variation of f0F2 shows a systematic change with the sunspot cycle and that this change in type of f0F2 daily variation is also fairly closely connected with the phase shift in the geomagnetic Sq variations. Thus it would be confirmed that the change in type of the daily variation of f0F2 with the sunspot cycle is interpreted mainly by the phase shift of the vertical drift, associated with the geomagnetic variation.
