## 1 Introduction
[43] used an ionosonde within the totality path and \(\sim\)500 GNSS receivers localized over South America, which were compared with two ionosonde measurements. The authors modeled the ionospheric effects in the Sheffield University Plasmasphere-Ionosphere Model (SUPIM). Also, they corroborated the relationship between diminishing solar radiation with densities below 200 km and the E and F1 layer critical frequencies. [PERSON] and [PERSON] [6] analyzed TEC depletion and applied the omega-k technique, which was based on a 3D Fast Fourier Transform. [PERSON] et al. [15] simulated in the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) the thermospheric perturbations induced by four different eclipses, such as TSE2019. TADs are induced by fast-moving shadows form bow wavefronts during the eclipse and evolve into freely propagating large-scale TADs after the eclipse ends. During TSE2019, TADs propagated in a direction with a smaller solar zenith angle that deviated from the eclipse trajectory. The 14 December 2020 total solar eclipse (TSE2020) took place in the southern hemisphere summer (subsolar latitude \(\sim\)23\({}^{\circ}\)S) between 13.56 UT and 18.88 UT, and its geographic location was similar to TSE2019. The DVTEC values had \(-\)40% to \(-\)20% in the penumbra compared to the background TEC during TSE2020. Therefore, TSE2020 had similar ionospheric values to the values obtained for TSE2019. On average, the maximum dimming occurred 20 to 30 min after MOT of the eclipse at the location of the GPS stations. However, the southern EIA crest was characterized by an ionospheric decrease (DVTEC between \(-\)50% to \(-\)30%) during TSE2020, as opposed to TSE2019. Previously, [PERSON] et al. [44] used SUPIM, and were the first to anticipate the ionospheric effect due to TSE2020. They modified the SUPIM to simulate the behavior of solar obscuration on the ionosphere at low and middle magnetic latitudes. [PERSON] [45] compared TEC variations using 46 GNSS stations around the path of the umbra of the eclipse to that predicted by the SAMI3. The results showed that TEC perturbations after totality could be triggered by orographic gravity waves (oGWs) not related to the eclipse. The passage of TSE2020 across the Andes Mountains aided the propagation of orographic gravity waves to ionospheric heights. [PERSON] et al. [11] simultaneously analyzed the ionospheric and geomagnetic responses to TSE2020. They used data from GNSS stations located in the Argentine and Chilean sectors. The authors analyzed the relationship between VTEC and geomagnetic changes. [PERSON] et al. [27] analyzed the effects of TSE2020 over the Brazilian sector using two digisonde data sources, GNSS-TEC, and the MIRE numerical model. Additionally, [PERSON] et al. [46] analyzed eclipse effects on critical ionospheric frequency variability, considering two ionosondes with similar geographical latitudes and a 95% obscuration percentage. They also compared the ionospheric response with the IRI-2016 model. [PERSON] et al. [13] used 36 Chilean GPS stations localized across both sides of the totality line. Although they observed strong AGWs at the GPS stations located north of the path of totality, the AGWs had no noticeable impact on the VTEC of these sites. They found the presence of large variability in the background VTEC values during TSE2020. The authors also compared the ionospheric effects of TSE2019 and TSE2020. [PERSON] and [PERSON] et al. [47] examined the space-based measurements (Swarm-B/C, COSMIC, and ICON/MIGHTI missions) of equatorial electrojet, zonal winds, and \(N_{e}\) for TSE2020. They reported the evident decrease in equatorial electrojet (\(<\!-29\%\)) during the solar eclipse, in comparison with non-eclipse. Recently, [PERSON] et al. [48] used data from multiple instruments (ionosondes, an Incoherent Scatter Radar, GNSS stations, and GOLD and Swarm-A missions) to evaluate the ionospheric prediction for a solar eclipse over South America conducted by [44]. [PERSON] et al.