| Autor: |
Adebesin, B. O., Adeniyi, J. O., Afolabi, P. A., Ikubanni, S. O., Adebiyi, S. J. |
| Předmět: |
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| Zdroj: |
Radio Science; May2022, Vol. 57 Issue 5, p1-19, 19p |
| Abstrakt: |
The F2‐layer propagation factor M(3000)F2 is important to ionospheric studies owning to its use in high High frequency radio communication/ionospheric modeling. This study focused on reducing the shortcomings in the use of M(3000)F2 IRI‐model for obtaining hmF2, especially in the African equatorial region, by obtaining an empirical "constructed model" (M(3000)F2CM) using the Korhogo (geomag. lat. 1.26°S, long. 67.38°E, dip. −0.67°S) data (M(3000)F2KOR). The data spans 8 years (1993–2000) under magnetically quiet conditions (Ap < 20 nT). The Regression method technique was used in obtaining the M(3000)F2CM. The regression coefficient (R2) for the M(3000)F2KOR versus F10.7 relationship was stronger during the solstices. The associated diurnal equations obtained for all seasons from the regression plot of the M(3000)F2KOR‐F10.7 relationship were used to obtained the constructed model equation given by M(3000)F2CM(m)i = ai(m) ∗ (F10.7) + bi(m), which allows the prediction of diurnal, seasonal and solar cycle variation of the M(3000)F2 parameter. M(3000)F2CM predicted well when tested at different solar activities. Generally, M(3000)F2CM performed reasonably well in comparison with the IRI model (M(3000)F2IRI) when validated with Ouagadougou (lat. 0.59°S, long. 71.46°E) observed data ‐ M(3000)F2OUA. The percentage deviation of M(3000)F2CM versus M(3000)F2OUA during high solar activity and low solar activity ranges from −10.8–5.3/−7.6–15.8 for solstices/equinoxes; whereas percentage deviation of M(3000)F2IRI versus M(3000)F2OUA spans −15.5–9.2 and −9.7–17.7 in similar order of seasons. The characteristic diurnal post‐sunset drop in M(3000)F2, a prominent feature of the equatorial ionosphere is well captured by the empirical model. These results suggest that the new model has a measure of potential for its use in the equatorial African region. Key Points: The characteristic diurnal post‐sunset trough in M(3000)F2 feature immediately after sunset is well captured by the empirical modelThe empirical constructed model allows the prediction of diurnal, seasonal and solar cycle variation of the M(3000)F2 parameterThe "constructed model" (M(3000)F2CM) performed well when tested at different solar activity conditions [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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