The dependence on the geomagnetic activity of changes in the fof2 values at the high latitudes

In this study, changes according to invariant magnetic latitude (Λ) of the hourly foF2 data that are taken from seven ionosondes stations are situated at between 60o-90o invariant magnetic latitude as known high latitude region are investigated for different geomagnetic activity conditions during December 1971-September 1972. The results are compared with electron density data measured by Ariel 4 satellites at about 550 km. According to the results obtained from the analyzes, it was found that the values of foF2 and electron density in the daytime are larger than those in the nighttime, and the values of foF2 and electron density in these hours decreases with the increasing of the magnetic latitude the except for the magnetic latitude region between about 68o and 72o. At night time, it was observed that the foF2 and electron density values increases between about 69o and 70o latitudes, while the foF2 and electron density values decreases at larger and smaller latitudes than these latitudes. It is also observed that seasonal and geomagnetic activity changes have a significant influence on the latitudinal changes of the foF2 and electron density values. The foF2 and electron density values in the geomagnetic quiet condition are larger than the foF2 and electron density values in the geomagnetic active conduction. Especially in the geomagnetic active conduction of the December period, the polar cap and polar oval zones are more prominent and have a larger latitudinal structure.