Assessment of the predictive capabilities of NIGTEC model over Nigeria during geomagnetic storms

Response of the American equatorial ionization anomaly to 2016 Arctic sudden stratospheric warming events

“…GPS-TEC processing software (Seemala, 2010) removes both the satellite and receiver biases by leveling both the pseudo range and carrier phase measurement (Ciraolo et al, 2007) in order to estimate the relative slant total electron content (STEC). The satellite biases are provided from the University of Bern, while the associated TEC variability which minimizes between 02:00 and 06:00 LT were used to estimate receiver biases (Amaechi et al, 2021). The absolute STEC was converted into VTEC using the ionospheric thin-shell model with an ionospheric pierce point (IPP) altitude of roughly 350 km (Mannucci et al, 1993).…”

“…The computed Diono comprises both the disturbance dynamo (Ddyn) current system and the disturbance polar number 2 (DP2) field-aligned current system. Typically, the prompt penetration electric field (PPEF) is related to the DP2 fieldaligned current system (Nishida, 1968;Amaechi et al, 2021).…”

Ionospheric Phase Scintillation Index Estimation Based on 1 Hz Geodetic GNSS Receiver Measurements by Using Continuous Wavelet Transform

“…Space weather refers to conditions on the sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health (Khazanov, 2016). As a result of space weather disturbances, the electron density of the ionosphere along receivers' line-ofsight varies rapidly, making the ionospheric scintillation be closely related to interplanetary magnetic fields and geomagnetic field disturbances, especially in high-latitude regions (Amaechi et al, 2021;Fathy & Ghamry, 2021;Goldovsky & Luria, 2004;Maltseva & Nikitenko, 2021). Therefore, the correlation between the detected scintillation rate and the parameters of space weather condition, for example, Ap, can be further adopted to evaluate the performance of the 𝐴𝐴 𝐴𝐴∅𝑓𝑓𝑓wavelet index, as the correlation given by the 𝐴𝐴 𝐴𝐴∅𝑓𝑓𝑓wavelet index should be similar to that of the 𝐴𝐴 𝐴𝐴𝜙𝜙 index if the 𝐴𝐴 𝐴𝐴∅𝑓𝑓𝑓wavelet index can monitor scintillations accurately.…”

“…Space weather refers to conditions on the sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space‐borne and ground‐based technological systems and can endanger human life or health (Khazanov, 2016). As a result of space weather disturbances, the electron density of the ionosphere along receivers' line‐of‐sight varies rapidly, making the ionospheric scintillation be closely related to interplanetary magnetic fields and geomagnetic field disturbances, especially in high‐latitude regions (Amaechi et al., 2021; Fathy & Ghamry, 2021; Goldovsky & Luria, 2004; Maltseva & Nikitenko, 2021). Therefore, the correlation between the detected scintillation rate and the parameters of space weather condition, for example, Ap, can be further adopted to evaluate the performance of the $${\sigma }_{\varnothing f,\mathrm{w}\mathrm{a}\mathrm{v}\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{t}}$$ index, as the correlation given by the $${\sigma }_{\varnothing f,\mathrm{w}\mathrm{a}\mathrm{v}\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{t}}$$ index should be similar to that of the $${\sigma }_{\phi }$$ index if the $${\sigma }_{\varnothing f,\mathrm{w}\mathrm{a}\mathrm{v}\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{t}}$$ index can monitor scintillations accurately.…”