## 4 Discussion
### Ionospheric Behavior
The decrease in foF2 and hmF2 is notorious at stations near the anomaly's crest (RA, FZ, CP); however, it is not very significant in the stations at the magnetic equator (SL). Moreover, similar ionospheric effects were seen in distant regions in the moon's shadow [16; 17; 18; 19; 20; 51; 52; 53; 54; 55; 56]. Differences between foF2 and TEC may be due to the fact that foF2 was the result of the original autoscaled records, and also that TEC was calculated from a spatial average. Figure 10: Comparison between TEC differences and differences in the critical frequency of the plasma (foF2) and its height (hmF2). Observations (red circles), reference variation (black line), and P1–P4 time (shaded interval) are shown. A possible explanation for this phenomenon is that the eclipse could alter the thermospheric neutral wind regime and thus generate a ionospheric disturbance dynamo, which could be observed at the equator as a counter-electrojet. This counter-electrojet could be observed in the vertical drift of the plasma, for instance, the one measured by the Jicamarca incoherent radar. However, there are no measurements at Jicamarca for this period. Another way to observe is to calculate the difference in the horizontal component between an equatorial magnetometer and another in low latitude [57], or in the temporal variation of the same horizontal component of an equatorial magnetometer. In this case, neither the difference between Jicamarca (12.0\({}^{\circ}\)S, 76.8\({}^{\circ}\)W, I = 1\({}^{\circ}\))--Piura (5.2\({}^{\circ}\)S, 80.6\({}^{\circ}\)W, I = 11\({}^{\circ}\); available at [[http://lnsn.igp.gob.pe/](http://lnsn.igp.gob.pe/)]([http://lnsn.igp.gob.pe/](http://lnsn.igp.gob.pe/)), last accessed on 22 May 2022), in the west coast of South America, nor the variation of the magnetometer of Kourou (5.2\({}^{\circ}\)N, 52.7\({}^{\circ}\)W; I = 13\({}^{\circ}\); available at [[https://intermagnet.github.io](https://intermagnet.github.io)]([https://intermagnet.github.io](https://intermagnet.github.io)), last accessed on 22 May 2022), in the east coast of South America shows significant variations during the eclipse day with respect to the other days (figure not shown), which rejects this hypothesis. Another possible explanation could be that due to the fact that the partial eclipse begins at low latitudes (see Supplementary Materials, Video S1) the electron concentration never reaches normal values again. An eclipse also can cause effects on a global scale. Because the eclipse-induced abrupt cooling of the atmosphere can result in an instantaneous temperature shift and pressure differential, triggering AGWs, and associated TADs and/or TIDs. However, a detailed investigation of these causes is out of the scope of the current paper [17]. On the other hand, ionospheric effects in the magnetic conjugate of the eclipse (end of the white line in Figure 3, at 10.70 UT) are not possible to observe due to the lack of receivers in this region (see Figure 1). On DoY 161, there was low ROTI activity in the western region of the United States of America, compared to the reference DoYs. The decrease in the percentage of GNSS stations in South America with weak ROTI activities caused the increase of stations without activity up to 89%. Then, the number of stations with strong ROTI activity only increased from 1% to 3% in this sector. However, the behavior of the ROTI activity in Greenland was less than the reference days (see Figures 6 and 7; Supplementary Materials, Table S4). The behavior of ionospheric TEC and ROTI shows that electrons were less active in the ionosphere during the solar eclipse (see Table 1, and Figures 3, 4, 6-8 and 10). The behavior of the ROTI in the eclipse region was consistent with that indicated by [PERSON] et al. [26]. They found a significant reduction in the ROT during the eclipse. Furthermore, eclipse day was the least ROTI active in Greenland because we were able to observe a clear reduction in ROTI values compared to the other four DoYs (see Figure 6 (left panels), Figure 7 (upper panels)).