## 3 Results
### Ionospheric Changes Using LEO Satellite Measurements  
Figures 7 and 8 show the high ionospheric values in low latitudes and part of the middle latitudes, around the region where the southern EIA crest is located, measured by the SwA and F18 satellites. Figure 7 illustrates the ionospheric behavior for PSE2022 using SwA measurements. We do not show the ionospheric data of PSE2018 because the satellite passes do not cover the region of interest during the eclipse. Then, we present  
Figure 6: TEC behavior during PSE2018 (**left panel**) and PSE2022 (**right panel**) in selected stations. GPS stations are ordered by latitude. MPO is presented next to each station name. VTECe (red dashed line), \(\overline{VTEC}\) (green dashed line), and DVTEC (%) (blue line) are represented. GE (red dotted line), MOT (black dotted line), C1–C4 (yellow bar), and P1–P4 (light blue bar) are also shown. GPS-VTEC at 850 km altitude (400 km above SwA), and in situ \(N_{e}\) and \(T_{e}\) measurements made by SwA Langmuir probes (at 450 km ionospheric height) on DoY 120 compared to two geomagnetic quiet days (DoYs 115 and 125). We chose the four SwA passes that best fit the eclipse region and eclipse time window over our region of interest (51\({}^{\circ}\)W, 74\({}^{\circ}\)W, 98\({}^{\circ}\)W, and 121\({}^{\circ}\)W). Two consecutive descending passes of SwA, the first 74\({}^{\circ}\)W (between 20\({}^{\circ}\)S and 0\({}^{\circ}\)), and the second 98\({}^{\circ}\)W (between 30\({}^{\circ}\)S and 20\({}^{\circ}\)S), show the clear increase in the values of the southern EIA crest (e.g., maximum DVTEC \(\sim\) 65% and \(>\)10 TECu). We were able to observe ionospheric effects under the penumbra centered between 70\({}^{\circ}\)S and 30\({}^{\circ}\)S. Although Figure 7 cannot be easily seen, we present our findings below where the first SwA pass (51\({}^{\circ}\)W) took place more than an hour before P1 (18.75 UT), where TEC changes were from \(-\)13% to 20% (from \(-\)0.3 to 0.8 TECu); \(DN_{e}\) were from 17% to 64% (from 0.09 \(\times\) 10\({}^{5}\) el/cm\({}^{3}\) to 0.68 \(\times\) 10\({}^{5}\) el/cm\({}^{3}\)); and \(DT_{e}\) had fundamentally around \(-\)5%, with respect to the background ionospheric values. The second pass (74\({}^{\circ}\)W) was close to P1. The minimum DVTEC was \(-\)30% (\(-\)1 TECu) at 54.0\({}^{\circ}\)S at 18.74 UT. The minimum \(DN_{e}\) was \(-\)4% (\(-\)0.03 \(\times\) 10\({}^{5}\) el/cm\({}^{3}\)) at 49.4\({}^{\circ}\)S at 18.72 UT; and the minimum \(DT_{e}\) was \(-\)34% (from \(\sim\)3100 K to \(\sim\)2100 K) at 48\({}^{\circ}\)S, in relation to the baseline values. The third satellite pass (98\({}^{\circ}\)W) occurred minutes prior to GE (20.69 UT). The minimum DVTEC was \(-\)52% (\(-\)1.5 TECu) at 64.6\({}^{\circ}\)S at 20.34 UT. The minimum \(DN_{e}\) was \(-\)45% (\(-\)0.34 \(\times\) 10\({}^{5}\) el/cm\({}^{3}\)) at 57\({}^{\circ}\)S at 20.3 UT; and the minimum \(DT_{e}\) was \(-\)22% (from \(\sim\)3200 K to \(\sim\)2500 K) at \(\sim\)54\({}^{\circ}\)S, with respect to the background values. The fourth selected pass of SwA (121\({}^{\circ}\)W) happened before P4 (22.63 UT). The minimum DVTEC was \(-\)45% (\(-\)2.1 TECu) at 54.2\({}^{\circ}\)S at 21.84 UT. The minimum \(DN_{e}\) was \(-\)31% (\(-\)0.36 \(\times\) 10\({}^{5}\) el/cm\({}^{3}\)) at 40.5\({}^{\circ}\)S at 21.78 UT; and the minimum \(DT_{e}\) was \(-\)14% (from 3600 K to 3100 K) at \(\sim\)53\({}^{\circ}\)S, regarding background values. Also, \(DT_{e}\) had values fundamentally around \(\pm\)100 K.  
On the other hand, to study the ionospheric changes during PSE2018, we used in situ \(N_{e}\) measurements from two passes of the F18 satellite over the region of interest (see Figure 8a,b). We compare the ionospheric behavior of the day of the eclipse of 2018 (DoY 46) with respect to the mean \(N_{e}\) of the two geomagnetically quiet days (DoYs 41 and 51).