Comparison of IRI‐2016 F2 Layer Model Parameters with Ionosonde Measurements

Abstract

International Reference Ionosphere (IRI) is the international standard ionospheric climatic model. Since the original formation of the international task force in 1970s, the IRI model has been continuously improved by ingesting developments in research in ionosphere. The most current version, namely, IRI‐2016, is offered with International Radio Consultative Committee (CCIR) and International Union of Radio Science (URSI) model choices with “STORM” option for the F2 layer critical plasma frequency (foF2) and BSE‐1979, AMTB‐2013, and SHU‐2015 options for maximum ionization height, hmF2. Since these two parameters are the determining values for the other model outputs, the evaluation of the options offered by IRI‐2016 is critical for various applications. In this study, all foF2 and hmF2 model options offered online at http://irimodel.org are computed for winter and summer solstice and equinox seasons of 2011 and 2015 at the locations of all available ionosondes and for all measurement intervals. The ionosondes are grouped into northern and southern midlatitude, northern and southern high‐latitude and equatorial regions. Individual, regional and global model output foF2 and hmF2 values are compared with those of ionosondes in both root‐mean‐square (RMS) and normalized RMS (NRMS) senses. For foF2, “STORM ON” can be used any time and in any region. Equatorial and high‐latitude regions have larger RMS values due to the sparse ionosondes. In northern midlatitude and high‐latitude regions URSI, in all other regions CCIR is the better option. For hmF2, SHU‐2015 and BSE‐1979 options provide a better fit for all regions, seasons, and years.

Towards a Real-Time Description of the Ionosphere: A Comparison between International Reference Ionosphere (IRI) and IRI Real-Time Assimilative Mapping (IRTAM) Models

“…However, in that analysis the oldest Bilitza et al [41] hmF2 IRI option was used as comparison. When using the newest Shubin et al [44] default IRI hmF2 option, we find much lower differences between IRTAM and IRI, thus confirming the very important step forward made by IRI about the hmF2 modeling, as on the other hand recently outlined by different authors [69][70][71].…”

Variations in the Maximum Electron Density of the F₂ Layer (NmF₂) over the Middle Latitude Station of Grahamstown, South Africa, during Solar Cycle 23

“…The occurrence of this anomaly has been attributed to the effects of neutral wind composition, temperature, electric field, and other chemical parameters, such as the O/N2 ratio. Neutral particles are transported from the southern hemisphere to the northern hemisphere during different solar activity epochs [16,20,[32][33][34][35][36][37][38][39]. Winter anomaly is usually an equatorial and lowlatitude ionospheric phenomenon.…”

Evaluation of foF2 and hmF2 Parameters of IRI-2016 Model in Different Latitudes over China under High and Low Solar Activity Years

“…In order to better predict foF2 and hmF2 accurately, some scholars have studied foF2/hmF2 modeling and accuracy evaluation using multi-source data [7][8][9][10][11][12][13], meanwhile, relevant scholars have studied the adaptability analysis of IRI hmF2/foF2 under different geomagnetic activities in different research areas. Some scholars have studied the adaptability of IRI model in different latitudes with ionosonde data [14][15][16][17][18][19][20]. Some scholars have also studied the adaptability analysis of F2 parameters and improved methods of IRI model during different geomagnetic storms [21][22][23][24][25].…”