Modeling of the Ionospheric Critical Frequency of the F₂ layer over Asia based on Modified Temporal‐Spatial Reconstruction

Abstract

A model based on modified temporal‐spatial reconstruction is proposed to improve the accuracy of predicting the monthly median ionospheric critical frequency of the F2 layer. This model has three new characteristics. (1) The solar activity parameters of the 10.7‐cm solar radio flux and sunspot number are together introduced into temporal reconstruction. (2) Both the geomagnetic dip and its modified value are chosen as features of the geographical spatial variation for spatial reconstruction. (3) Harmonic functions are used to represent the ionospheric critical frequency of the F2 layer, which reflects seasonal and solar cycle variations. Furthermore, combining the least squares fitting regression for these characteristics with harmonic analysis, a valid model can be established from vertical sounding data spread across three ionospheric regions (high, middle, and low latitudes in Asia). Statistical results reveal that the ionospheric critical frequency of the F2 layer calculated by the proposed model is consistent with the trend of the monthly median observations. The average root‐mean‐square error is only 0.70 MHz (corresponding to relative error 11.30%), reflecting that our model outperforms the International Reference Ionosphere model with International Union of Radio Science and Consultative Committee on International Radio (CCIR) coefficients. Moreover, the proposed method has great potential in terms of providing higher prediction accuracy for ionospheric parameters on the global scale.

Power Spectrum Inception of F2 Layer at Solar Terrestrial Region of Pakistan

“…F1 and F2 are higher than and E responsible to communicate signals of high frequencies. The uniqueness of F1 and F2layers is that they remained active during night because of high degree of ionization according to Saha's preposition (Gurevich 1978;Kelley 2009;Zubair et al 2011;Piel and Brown 2011;Yamazaki and Maute 2017;Wang et al 2019). Moreover, the characteristics of ionospheric layers Es and F2 including F1 at Karachi station studied during the solar cycles 21, 22 and 23 (Talha et al 2019).…”

“…This is a well known fact that F 2 layer of the ionosphere can be responsible as one of the most essential variable of our atmosphere. The variability of this entirely dependent particular region on dynamics of sunspots and solar bursts (Szwabowski 2016;Wang et al 2019,Liu et al 2011Li et al 2016). It has been declared that the temperature of the atmosphere increases tremendously within the layer that intern produces the enhancement in the electron density of the same region (Abdullah 2011).The most important causes of ionization of Earth's ionospheric F 2 layer are solar EUV radiations (de Haro Barbás and Elias 2020).…”

A High Accuracy Spatial Reconstruction Method Based on Surface Theory for Regional Ionospheric TEC Prediction

“…The changes in the near‐earth space environment will lead to serious space weather hazards and meteorological disasters, threatening human life and property. As one of the important components of the near‐earth space environment, the ionosphere lies 60–1,000 km above the ground and is an electrically neutral plasma region composed of electrons, ions, and neutral particles (Wang, Ma, et al., 2019). The ionosphere is affected by many uncertain factors, such as solar electromagnetic radiation and geomagnetic disturbance, and presents complex and uneven variations in time and space scale, accompanied by certain randomness.…”

A Combination Prediction Model of Long-Term Ionospheric foF2 Based on Entropy Weight Method

“…The critical frequency of the F2 layer of the ionosphere (foF2) is one of the most important parameters in various civil and military applications [ 1 , 2 ]. The foF2 parameter is not only used for designating the maximum usable frequency (MUF) and the lowest usable frequency (LUF) of the high frequency (HF) communication systems [ 3 ], but also its spatiotemporal variability will affect the efficiency of radar and navigation systems [ 4 , 5 ].…”