Equinoctial asymmetry trend extraction from total electron content based on spectrum analysis.

The ionospheric Equinoctial Asymmetry (EA) and signifies ionospheric behavior has been studied over the Grid-Point (Geographic 134.05° E and 34.95° N) during the period 1997 to 2016. The Singular Spectrum Analysis (SSA) characterizes the EA of Ionospheric Total Electron Content (TEC). The behavior of the ionospheric TEC to the EA response depends on the season and local time, location, and solar activity. The data selection of TEC is based on the solar activity index (F10.7) F10.7 ≥ 105 and the magnetic activity index (AP) Ap ≤ 25. TEC datasets of F10.7 ≥ 105 and Ap ≤ 25 days from 1997 to 2016 are used for model development. A strong dependence on solar activity was explained by the first dominant SSA mode, which is a function of solar activity that increased with increasing solar activity throughout the period. The results showed that the increase in the variability of the ionosphere and the solar activity used in equinoctial asymmetry analysis could affect TEC's daytime and nighttime availability. In this scenario, the EA variability of the ionosphere TEC is a daytime phenomenon and occurs at night during the period 1997 to 2016. Moreover, the overview of statistical analysis is added to our examination to elaborate further on annual and semi-annual phenomena in the ionosphere at mid-latitudes during the day and night. [ABSTRACT FROM AUTHOR]