## 3 Results
### Ionospheric Behavior and TEC Maps  
From the data of each station, we can estimate the VTEC for each station during the selected period of days. By using the ordinary Kriging interpolation, as described in Section 2.1, it is possible to obtain VTEC maps. Figure 3 shows a summary of the TEC maps by contrasting the eclipse (VTECe) and control (\(\overline{VTEC}\)) days. We present some particular hours: 09.15 UT, 10.70 UT (GE time), 12.00 UT, 13.19 UT (P4 time), 13.72 UT (P4 time \(+\)\(\sim\)0.5 h), and 17.66 UT. Figure 3 also shows the eclipse masks from 20% obscuration and with intervals of 20%, at 350 km altitude (white line). From these figures, it is possible to notice that the Greenland and South American sectors are two of the most affected in terms of VTEC depletion. VTECe in IPP and DVTEC[TECu] in Figure 3 use the Kriging interpolation method and are shown in equidistant cylindrical projection and Northern Hemisphere polar plots (see Supplementary Materials, Figure S1). The 09.15 UT, 12.00 UT, and 13.72 UT maps were chosen in particular because they show the greatest apparent position variations during the eclipse time window. The 17.66 UT map was chosen because the ionosphere was roughly recovered by that time. For a better visualization of the eclipse effects, a third column has been incorporated where the VTEC differential in TEC units (DVTEC[TECu]) is shown. DVTEC had values of around \(-20\%\) (\(-2\) TECu) over the oceanic sectors when the eclipse began (P1-time). However, at these locations, the GNSS receivers are scarce, which can cause less reliable interpolation. This value could be considered as part of the non-significant variations in DVTEC. A similar problem is identified over Central Africa, where there is a value of \(50\%\) (7 TECu), possibly also due to the few receivers in this area (see Figure 1). The anomalies in these areas were observed more than 5 h before the eclipse. We will focus mainly on changes generated over the continental areas of America and Europe, while the other areas will not be considered for this analysis. When the ionospheric TEC effects due to eclipse have already begun, the 09.15 UT maps show a slight depletion of \(-30\%\) (\(-1\) TECu) across eastern Canada under the shadow of the eclipse. At 10.70 UT (GE-time), these changes expand beyond the shadow area of the eclipse (see second row of Figure 3). The 10.70 UT maps show that ionospheric TEC  
Figure 3: Ionospheric TEC maps during the 10 June 2021 Annular Solar eclipse using the Kriging interpolation method. From left to right panels: VTECe, \(\overline{VTEC}\), and DVTEC[TECu]. From top to bottom panels: 09.15 UT, 10.70 UT (GE time), 12.00 UT, 13.19 UT (P4 time), 13.72 UT, and 17.66 UT. Eclipse obscuration masks from 20% obscuration and with intervals of 20%, at 350 km altitude (white line) are shown. The white dashed line starts from the maximum obscuration of the solar eclipse to its conjugate location in the Southern Hemisphere at 350 km altitude. depletion did not only occur across the obscuration region over the Northern Hemisphere. DVTEC[%] had values of around \(-60\%\) (\(-4\) to \(-2.5\) TECu) over the South and East coasts of Greenland, \(-50\%\) (\(-3\) TECu) eastern Canada, and around \(-50\%\) (\(\sim\)\(-3\) TECu) over the Lesser Antilles. The 12.00 UT, 13.19 UT, and 13.72 UT maps show DVTEC[%] had values of around \(-30\%\) (\(-3\) to \(-1.5\) TECu) over Russia after GE time. Figure 3) also illustrates how the TEC disturbance moved from West to East over the Northern Hemisphere, following the path of the annular solar eclipse. At 12 UT, there is a recovery of the ionospheric TEC over Canada and Greenland regions, but DVTEC[%] had values of less than \(-50\%\) in East coast of Greenland. Ionospheric TEC depletion had values of around \(-60\%\) (\(\sim\)\(-5\) TECu) over the Lesser Antilles near the north crest of Equatorial Ionization Anomaly (EIA) and less than \(-30\%\) (\(\sim\)\(-5\) TECu) appeared over South America near the south crest of EIA.