## 5 Results and Discussion
### Comparative and Qualitative Analysis
While the overall intensity was lower than the sunrise peak, localized enhancements indicated lingering effects of solar radiation. The ConvGRU-L\({}_{\rm C}\) model again excelled, closely mirroring observed conditions and effectively capturing the nuanced spatial dynamics of the ionosphere. The ConvGRU-L\({}_{\rm log-cosh}\) model, recognizing the general decline in activity, presented a broader distribution of scintillation than observed patterns, which could detract from its utility in precise operational contexts. The ConvGRU-L\({}_{\rm S}\) model showed considerable inaccuracies, notably underestimating both scintillation intensity and localization capabilities. Figure 7: Observed and predicted S4 maps for South America on 30 th March in 2015 and 2020 at three time points. The figure displays maps at sunrise (06:10 LT–11:10 UT), solar noon (12:05 LT–17:05 UT), and sunset (18:00 LT-23:00 UT). The first column illustrates the observed S4 values, while the subsequent columns show predictions from the ConvGRU-L\({}_{\rm C}\), ConvGRU-L\({}_{\rm log-cosh}\), and ConvGRU-L\({}_{\rm S}\) models, respectively. Figure 8: Observed and predicted S4 maps for South America on 31 st July in 2015 and 2020 at three time points. The figure displays maps at sunrise (06:30 LT–11:30 UT), solar noon (12:05 LT–17:05 UT), and sunset (17:40 LT–22:40 UT). The first column illustrates the observed S4 values, while the subsequent columns show predictions from the ConvGRU-L\({}_{\rm C}\), ConvGRU-L\({}_{\rm log\,cosh}\), and ConvGRU-L\({}_{\rm S}\) models, respectively. The 2020 sunrise map displays high activity along the equatorial anomaly, similar to 2015 but with reduced intensity, likely due to the solar minimum's diminished impact on the ionosphere (as detailed in Figure 6). The ConvGRU-L\({}_{\rm C}\) model excelled at accurately replicating these patterns, capturing both the intensity and spatial distribution effectively, despite minor discrepancies in gradient smoothness. In contrast, the ConvGRU-L\({}_{\rm log\text{-}cosh}\) model offered a generalized depiction, diluting peak intensities and lacking the detail needed for precise forecasting. The ConvGRU-L\({}_{\rm\delta}\) model significantly diverged, underestimating scintillation intensity and poorly localizing high-activity areas, demonstrating limited sensitivity to rapid changes at sunrise. By noon, activity decreased further, with scintillation primarily confined to the equatorial regions, reflecting a more stable ionospheric state due to decreased solar activity. The ConvGRU-L\({}_{\rm C}\) model aligned closely with observed data, showing nuanced modeling capabilities by accurately reflecting both the reduced intensity and geographic distribution. In contrast, the ConvGRU-L\({}_{\rm log\text{-}cosh}\) model suggested an overestimation of disturbances with its broader dispersion, while the ConvGRU-L\({}_{\rm\delta}\) model displayed a significant reduction in activity and failed to accurately depict high-activity zones, indicating an underestimation of ionospheric disturbances. At sunset, ionospheric activity in 2020 was significantly lower than in 2015, with only subtle enhancements visible along the equatorial anomaly. The ConvGRU-L\({}_{\rm C}\) model replicated observed patterns with high accuracy, effectively resolving the equatorial anomaly and adjacent areas, albeit with slight overestimations in some regions. However, the ConvGRU-L\({}_{\rm log\text{-}cosh}\) model produced a more generalized spread of activity, potentially compromising its utility for precise applications by smoothing over intricate details. The ConvGRU-L\({}_{\rm\delta}\) model notably underestimated the scintillation activity, especially failing to capture critical intensity peaks necessary for accurate sunset predictions. The observed S4 map at sunrise on 30 March 2015, reveals substantial scintillation activity, especially near the equatorial ionization anomaly.