The Variations of High-Frequency Ionospheric Absorption Discrepancy Between the Ordinary and Extraordinary Wave During Daytime in China Region

By utilizing an ionospheric absorption model, the variations of high-frequency ionospheric absorption discrepancy between the X-mode and O-mode wave, at two different propagation direction links (north-south path and east-west path) in China region during the daytime, are explored. In this paper, the two main factors, namely frequency and propagation of direction, affecting on the trend of absorption difference between the X-mode and O-mode wave, are investigated. It is found that the absorption discrepancy between the X-mode and O-mode wave decreases with the increase in frequency, with the exception of two certain inflexion points under various elevation angle conditions. The entire decrease trend is attributed to the absorption coefficient, which is dominated by the parallel component of the magneto-ionic parameter. The occurrence of the two certain inflexion points (the first inflexion one is negative, the other is positive) on the absorption difference-frequency curves, resulting from the successive appearance of the Pedersen ray for the O-mode and X-mode, respectively. In addition, it is interesting that the absorption discrepancy in the north-south propagation link is always greater than that in the east-west propagation link at any frequency under various elevation angle conditions. It is mainly determined by the trend of the difference in the parallel component of the magneto-ionic parameter.