## 4 Discussion
### F10.7 and TEC  
The background TEC values during the EPS2022 period are notably higher than the background TEC values of the EPS2018 period. A possible explanation for this phenomenon is that the solar flux (F10.7) indices during PSE2022 (F10.7 were from 110.6 to 158.5 sfu) are higher than during PSE2018 (F10.7 were from 66.3 to 76.6 sfu), as shown in Figure 2. Additionally, PSE2022 occurred \(\sim\)2.5 years after the start of Solar Cycle 25, while PSE2018 occurred less than 2 years before the end of Solar Cycle 24 (see Figure 9). TEC changes are synchronized with solar cycles. Moreover, the dependency between solar index parameters (e.g., solar flux, extreme ultraviolet radiations, and sunspot number) and TEC has been studied by many researchers (e.g., [67; 68]). Therefore, we prefer to conduct the percentage analysis of TEC changes to compare the eclipses instead of using TECu. Figure 8: In situ electron density (\(N_{e}\)) data measured by DMSP 5D-3 F18 in the topside ionosphere at about 850 km height for PSE2018 (**a**,**b**) and PSE2022 (**c**,**d**). (**a**,**c**) \(N_{e}\) acquired via satellite orbit the magnetic equator (black line) are displayed on Earth maps. (**b**,**d**) Profile data on eclipse DoYs (DoY 46 of 2018; and DoY 120 of 2022; in red lines) compared with the mean \(N_{e}\) of the reference DoYs (DoYs 41 and 51 of 2018; and DoYs 115 and 125 of 2022, in green lines). The longitudes and time intervals of the satellite passes are also indicated. The influence of geomagnetic activity on changes in the ionosphere TEC was observed most clearly at mid and high latitudes (see Figure 4), but there were no significant effects of the geomagnetic activity in the low-latitude ionosphere over South America (see Section 2.4 and Figure 3). Therefore, GPS stations at higher latitudes (in South America), although they had a higher percentage of obscuration, showed less influence on the effects of the eclipse than GPS stations at lower latitudes with a lower percentage of obscuration (see Table 1 and Figures 4 and 6). The days prior (since DoY 117) to PSE2022 showed some levels of geomagnetic activity. On 30 April 2022, the ionospheric behavior (DVTEC \(>40\%\)) observed in the six selected GPS stations coincided with the levels of geomagnetic activity between 0 UT and 6 UT (Kp = \(4^{+}\), Dst = \(-37\) nT, and Vsw \(>480\) km/s; see Figure 2). Subsequently, the DVTEC values began to decrease until around 12 UT (after sunrise in Chile), and then the ionospheric TEC started to increase until the eclipse impacts on the ionosphere could be observed. After the P1 time of the PSE2022, we could observe positive values of DVTEC over the six GPS stations between 13% and 34% with respect to the background ionosphere. Our findings related to the improvements in the ionospheric TEC at the six stations during the day of the 2022 eclipse were in agreement with the graphs shown by [PERSON] and [PERSON] [51]. Therefore, although geomagnetic forcing impacted the ionosphere [63], causing a positive increase in TEC during levels of geomagnetic activity, we could clearly see the ionospheric depletion during both eclipses. On the other hand, we were able to observe a TEC depletion of the southern EIA crest during PSE2018 but a TEC enhancement of the same crest during PSE2022 (see Figures 4-7). During the 2018 solar eclipse, we were able to observe a clear ionospheric TEC depletion (DVTEC \(\sim\)\(-50\%\)) in the EIA crest over South America. These TEC changes spread over South America as time passed. Our percentage of TEC depletion matches what [27; 48] showed in the southern EIA crest for TSE2020 over South America and the EIA depletion summary for different eclipses (DVTEC \(\sim\)\(-50\) to \(-20\%\)) by [27]. At least the eclipses of 2018 and 2020 happened in the summer hemisphere. Meanwhile, during the 2022 solar eclipse (hemisphere autumn), we can see a notorious TEC enhancement (DVTEC \(>30\%\)) relative to the background in the EIA crest over South America.