İbrahim ÜNAL, Aybaba HANÇERLİOĞULLARI, Seçil KARATAY, Ali YEŞİL

İyonosferik Plazmadaki Empedansın Mevsimsel Değişimi

İyonosfer, atmosferin 50 km ila 1000 km yükseklikleri arasında yer alan iyonlaşmış bir tabakadır. Bu tabaka, atmosferik iletkenlikte önemli bir rol oynar. İyonosfer büyük miktarda elektrik yüklü parçacıklara sahiptir ve bu nedenle radyo dalgalarının yayılımını etkiler. Bu çalışmada, iyonosferik plazmanın empedansı farklı mevsimler ve farklı jeomanyetik aktivite dönemleri için Yer’in gerçek geometrisi kullanılarak hesaplanmıştır. İyonosferik plazmanın empedansının her doğrultuda genel olarak her mevsim için büyük değerlere sahip olduğu gözlenmiştir. Empedans tensörünün diyagonal bileşenlerinin diğer bileşenlerden daha büyük olduğu bu çalışmada gözlenmiştir. Ayrıca iyonosferik plazmanın, genellikle, her yöne ve mevsimlerde zayıf iletkenliğe sahip olduğu gözlenmiştir. Empedansın, elektron yoğunluğuyla ters olarak değiştiği görülmüştür. Bu nedenle, elektron yoğunluğunda sapmalara neden olan jeomanyetik aktivitenin de empedansı azalttığı gözlenmiştir. İyonosferik plazmanın, çalışmanın yapıldığı coğrafi koordinatlarda reaktif bir karaktere sahip olduğu görülmüştür. İyonosfer, bir dielektrik yapı göstermiştir.

Seasonal variations of impedance in the ionospheric plasma

The ionosphere is an ionized layer that extends between 50 km and 1000 km altitudes in the atmosphere. It plays an important rolein atmospheric electricity. The ionosphere has the number of electrically charged particles and thus, it affects the propagation ofthe radio waves. In this study, magnitudes of impedance for different seasons and different geomagnetic activity periods in theionospheric plasma are calculated using the real geometry of Earth. It is observed that the impedance of the ionospheric plasma inall directions generally has high values for all seasons. The diagonal components of the tensor of the impedance are greater thanthe other components. It is also observed that the ionospheric plasma, generally, has weak conductivity in all directions and seasons.Impedance varies inversely with electron density. Hence, geomagnetic activity periods which lead to an increase in electron densitydecreases the impedance. It is observed that the ionospheric plasma has a reactive character in the geographic coordinates wherethe study was performed. The ionosphere displays a dielectric structure.

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