The behavior and dynamics of ionosphere are completely dependent on the solar activity. We have investigated the long term variability of ionospheric parameter foF2 with corresponding changes in the solar activity dur...The behavior and dynamics of ionosphere are completely dependent on the solar activity. We have investigated the long term variability of ionospheric parameter foF2 with corresponding changes in the solar activity during the 23rd solar cycle. The variation of the critical frequency of ionospheric foF2 at Syowa Station Antarctica, (69°S, 39°E) is examined with four different solar activity indices characterizing the long term variability of solar activity wise Flare Index, relative sunspot number (Rz), solar flux F10.7 cm and CME occurrence index. We compared the dependency of foF2 and other solar activity indices on each other by using linear correlation investigation, and showed the qualitative similarity of the ionospheric foF2 with the solar indices. We notice that hysteresis of foF2 is lower for the growing branches of the solar cycle. The individual dissimilarity of critical frequency foF2 demonstrated the dependency on the solar cycle but this variation was different during the months, which depended on solar activity and polar ionospheric behavior. The peak to peak variation between monthly average of critical frequency foF2 and solar indices parameter is evidence for the absolute dependency for each other. The linear correlation between the solar indices and foF2 is very strong during the climbing and downward branches of the solar cycle. However the incline of their linear fits shows variations from index to index.展开更多
文摘The behavior and dynamics of ionosphere are completely dependent on the solar activity. We have investigated the long term variability of ionospheric parameter foF2 with corresponding changes in the solar activity during the 23rd solar cycle. The variation of the critical frequency of ionospheric foF2 at Syowa Station Antarctica, (69°S, 39°E) is examined with four different solar activity indices characterizing the long term variability of solar activity wise Flare Index, relative sunspot number (Rz), solar flux F10.7 cm and CME occurrence index. We compared the dependency of foF2 and other solar activity indices on each other by using linear correlation investigation, and showed the qualitative similarity of the ionospheric foF2 with the solar indices. We notice that hysteresis of foF2 is lower for the growing branches of the solar cycle. The individual dissimilarity of critical frequency foF2 demonstrated the dependency on the solar cycle but this variation was different during the months, which depended on solar activity and polar ionospheric behavior. The peak to peak variation between monthly average of critical frequency foF2 and solar indices parameter is evidence for the absolute dependency for each other. The linear correlation between the solar indices and foF2 is very strong during the climbing and downward branches of the solar cycle. However the incline of their linear fits shows variations from index to index.
