## 3 Results
### Analysis of Ionospheric DVTEC Disturbances
#### 3.2.2 Comparison with a Day without Storms  
To analyze the ionospheric behavior during a thunderstorm, we chose a day in Argentina with no atmospheric electrical activity (AEA). We designated 9 September 2018 as the base day for comparative purposes. In this study, we chose 14 RAMSAC stations, whose distribution can be seen in Figure 14. The right image in the figure represents the lightning counts on a 0.2\({}^{\circ}\) by 0.2\({}^{\circ}\) grid. The points where the peak current of the different types of discharges were reported to have occurred by the Earth Network system are marked with a star. From Figure 14, we observe that the RAMSAC stations are distributed as follows:  
* Six stations in Zone 1: AZUL, CHOY, CORD, MZGA, PEBA, SRLP;
* Three stations in Zone 2: CHIM, SAJA, UNSJ; and
* Five stations in Zone 3: ESQU, ORAN, RIO2, SVIC, TERO. In addition, we can see that the AZUL and CHOY stations were the closest to the regions with the highest number of discharges. These stations, together with MZGA, were located near the highest current peaks. Note that SRLP and PEBA were located between the storms. When comparing the DVTEC variations between the two days (refer to Figure 15), it is evident that the day with AEA exhibited significant fluctuations in DVTEC. The stations with the highest variability are highlighted in light blue in Figure 15b. Three of the stations, namely, CHOY, MZGA, and PEBA, are situated in Zone 1, which corresponded to the storm region. Furthermore, the ESQU station also recorded considerable deviations in DVTEC, despite being located in Zone 3, specifically, in the Andes mountain range. Figure 14: Maps of the 14 RAMSAC stations on 9 September, reference day (**left image**), and on 10 November 2018, day with AEA (**right image**). On the 10 November map, lightning count is plotted on the 0.2\({}^{\circ}\) by 0.2\({}^{\circ}\) grid, and the locations where the highest current peaks occurred for intracloud (IC) and for Cloud-to-Ground (CG) discharges are indicated with stars. The peak-to-peak DVTEC amplitudes for each station throughout the study period (00:00 UTC-08:00 UTC) are shown in Figure 16 using multicolored diamonds, representing both the reference day (left panel) and the day with AEA (right panel). The lightning counts are also plotted on 0.2\({}^{\circ}\) by 0.2\({}^{\circ}\) grid. The points where the maximum peak current of the different types of discharges occurred are marked with stars. On the reference day, the peak-to-peak DVTEC amplitudes measurements from all the stations collectively spanned from 0.01 to 0.44 TECU. Conversely, on the day with AEA, peak-to-peak DVTEC amplitudes ranged from 0.21 TECU to 1.35 TECU. This indicates an increase in amplitude across all stations, likely due to the presence of thunderstorms. It is worth noting that, although stations CHOY and AZUL were located near the area of maximum discharge and peak current, they exhibited differences in their amplitude values. The same occurred with PEBA and SRLP, which were situated between the storms. Note that peak-to-peak DVTEC amplitudes ranging from 0.44 TECU to 0.67 TECU are predominant in the data. Figure 16: Same as Figure 14, presenting the peak-to-peak DVTEC amplitude values at each station as colored diamonds. Figure 15: Temporal variations in the differential vertical total electron content (DVTEC) of the 14 RAMSAC stations on the (**a**) reference day and (**b**) AEA day. On the y-axis, the stations are located 1 TECU apart. A scale is plotted for reference. Table 3 shows the DVTEC peak-to-peak amplitude of the 14 analyzed stations for the entire study period (00:00 UTC-08:00 UTC). In the table we can see that stations ESQU, MZGA, PEBA, RIO2, SAJA and TERO experienced an increase in their DVTEC peak-to-peak amplitudes of three or more times during the day of the storm compared to their reference peak-to-peak amplitude values. ESQU and RIO2 were situated south of the storm region and MZGA was within the storm zone, while PEBA, SAJA, and TERO were located north of the storm region.