Kara ve Havacılık Haberleşmeleri İle İlişkili İyonosferik HF Tahminleri Üzerine Jeomanyetik Etkiler

Bu çalışmada, 23. Güneş döngüsünün maksimumu boyunca orta enlemlerde IRI-2016’nın foF2 tahminleri üzerine jeomanyetik fırtınaların etkisi araştırılmıştır. Bunun için, 2000 yılı boyunca Roma ve Juliusruh iyonsonda istasyonlarından alınan ve aynı konumlar için IRI-2016'dan hesaplanan saatlik foF2 verileri kullanılmıştır. 3 saatlik gezegensel jeomanyetik aktivite indisi (3h-Kp) jeomanyetik aktivite göstergesi olarak kullanılmıştır. Jeomanyetik fırtınalı dönemler boyunca IRI-2016’nın performansını test etmek için iyonsonda istasyonlarından ölçülen gerçek foF2 verileri ve IRI-2016’dan hesaplanan tahmini foF2 değerleri kullanılarak yüzdelik sapma değerleri hesaplanmıştır. Bu analizler, ekinokslar (21 Mart, 23 Eylül) ve gündönümleri (21 Haziran, 21 Aralık) civarında jeomanyetik fırtınalı günler temel alınarak dört mevsim için yapılmıştır. Analiz sonuçlarından, jeomanyetik fırtınalı dönemler boyunca IRI-2016 foF2 tahminlerinin, iyonsonda istasyonlarından ölçülen gerçek foF2 değerlerinden büyük ölçüde saptığı ve bu sapmaların mevsimlere ve enlem değerine bağlı olarak değiştiği tespit edilmiştir.

Anahtar Kelimeler:

İyonosfer, Kritik frekans, IRI-2016, Jeomanyetik fırtınalar

Geomagnetic Effects on the Ionospheric HF Predictions Related to Ground and Aviation Communications

In this study, the effect of geomagnetic storms on the IRI-2016 foF2 predictions is investigated at middle latitudes during the maximum of the solar cycle 23. For this purpose, hourly foF2 data measured from the ionosonde stations Rome and Juliusruh for the year 2000 and hourly foF2 data calculated from IRI-2016 for the same locations and year are used. Planetary geomagnetic activity "3h-Kp" indices are used as a geomagnetic activity indicator. In order to test performance of the IRI-2016 for disturbed geomagnetic conditions, the percentile deviations is calculated using the estimated foF2 data from IRI-2016 and the real foF2 data from the ionosonde stations during the geomagnetic storms. This analysis is done for four seasons based on geomagnetic stormy days around equinoxes (March 21, September 23) and solstices (June 21, December 21). From these results, it is found that IRI-2016 foF2 predictions deviate considerably from the real foF2 data the ionosonde stations during geomagnetic disturbed periods and this deviations differ according to the seasons and latitude value.

Keywords:

Ionosphere Critical frequency, IRI-2016, Geomagnetic storms, Percentile deviationIonosphere,

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