KUZEY YARIMKÜREDEKİ YÜKSEK ENLEM foF2 DEĞERLERİNDEKİ DEĞİŞİMLERİN JEOMANYETİK AKTİVİTEYE BAĞLILIĞI.

In this study, changes according to invariant magnetic latitude of the hourly foF2 data that are taken from seven ionosondes stations are situated at between 60°-90° invariant magnetic latitude as known high latitude region are investigated for different geomagnetic activity conditions during December 1971-September 1972. According to the results obtained from the analyses, it was found that the foF2 values in the daytime are larger than those in the nighttime and while the foF2 values in these hours increase between about 68o and 72o invariant magnetic latitude, the foF2 values in larger and lower latitudes than these latitudes decrease with increasing magnetic latitude. At night time, it was observed that the foF2 values increases between about 66o and 72o invariant magnetic latitude, while the foF2 values exhibit a trough structure 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 values. The foF2 values in the geomagnetic quiet condition are larger than the foF2 values in the geomagnetic active conduction. Especially in the geomagnetic active conduction of the December, the polar cap and polar oval zones are more prominent and have a larger latitudinal structure. [ABSTRACT FROM AUTHOR]