## 6 Evaluation of Results
The FAR decreased substantially, from 0.34 to 0.19 in January and from 0.32 to 0.21 in March, indicating fewer false positives and greater predictive conservatism under lower solar activity. The CSI increased from 0.43 to 0.64 in January, and from 0.45 to 0.66 in March, demonstrating a higher accuracy in correctly predicting events relative to the total events forecasted and observed. Similarly, the POD improved from 0.59 to 0.80 in January, and from 0.61 to 0.81 in March, reflecting enhanced sensitivity in detecting true scintillation events. The TSS also rose from 0.53 to 0.72 in January, and from 0.55 to 0.73 in March, underscoring significant gains in the model's discriminative ability. For the ConvGRU-L\({}_{\text{Log-cosh}}\) model, similar trends were observed. The FAR reductions--from 0.36 to 0.20 in January, and from 0.34 to 0.22 in March--suggest an improvement in prediction specificity. The CSI improvements were notable, increasing from 0.41 to 0.62 in January and from 0.44 to 0.64 in March, indicating more effective event prediction. The POD showed robust gains, increasing from 0.56 to 0.78 in January, and from 0.59 to 0.79 in March, signifying a higher likelihood of detecting actual scintillations. The TSS improved from 0.51 to 0.70 in January, and from 0.53 to 0.71 in March, highlighting better discrimination between events and non-events. The ConvGRU-L\({}_{\text{S}}\) model also showed improvements across all metrics, although the changes were slightly less pronounced compared to the other two models. The FAR decreased from 0.37 to 0.21 in January, and from 0.35 to 0.23 in March. The CSI \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Period of Time**} & \multicolumn{4}{c}{**2015**} & \multicolumn{4}{c}{**2020**} \\ \cline{2-9}  & & **January** & **March** & **July** & **January** & **March** & **July** \\ \hline \multirow{4}{*}{**ConvGRU-L\({}_{\text{C}}\)**} & **FAR** & 0.34 & 0.32 & 0.28 & 0.19 & 0.21 & 0.16 \\ \cline{2-9}  & **CSI** & 0.43 & 0.45 & 0.52 & 0.64 & 0.66 & 0.70 \\ \cline{2-9}  & **POD** & 0.59 & 0.61 & 0.65 & 0.80 & 0.81 & 0.83 \\ \cline{2-9}  & **TSS** & 0.53 & 0.55 & 0.58 & 0.72 & 0.73 & 0.76 \\ \hline \multirow{4}{*}{**ConvGRU-L\({}_{\text{Log-cosh}}\)**} & **FAR** & 0.36 & 0.34 & 0.30 & 0.20 & 0.22 & 0.17 \\ \cline{2-9}  & **CSI** & 0.41 & 0.44 & 0.50 & 0.62 & 0.64 & 0.68 \\ \cline{2-9}  & **POD** & 0.56 & 0.59 & 0.62 & 0.78 & 0.79 & 0.81 \\ \cline{2-9}  & **TSS** & 0.51 & 0.53 & 0.55 & 0.70 & 0.71 & 0.74 \\ \hline \multirow{4}{*}{**ConvGRU-L\({}_{\text{S}}\)**} & **FAR** & 0.37 & 0.35 & 0.32 & 0.21 & 0.23 & 0.18 \\ \cline{2-9}  & **CSI** & 0.40 & 0.42 & 0.47 & 0.61 & 0.63 & 0.66 \\ \cline{1-1} \cline{2-9}  & **POD** & 0.55 & 0.57 & 0.58 & 0.76 & 0.77 & 0.79 \\ \cline{1-1} \cline{2-9}  & **TSS** & 0.49 & 0.51 & 0.54 & 0.69 & 0.70 & 0.72 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Prediction performance of the ConvGRU-L\({}_{\text{C}}\), ConvGRU-L\({}_{\text{Log-cosh}}\), and ConvGRU-L\({}_{\text{S}}\) models using statistical parameters such as the False Alarm Rate (FAR), Critical Success Index (CSI), Probability of Detection (POD), and True Skill Score (TSS) over South America during January and March of 2015 and 2020.  
rose from 0.40 to 0.61 in January, and from 0.42 to 0.63 in March, reflecting enhanced overall effectiveness. The POD increased from 0.55 to 0.76 in January, and from 0.57 to 0.77 in March, indicating greater detection capabilities. The TSS advanced from 0.49 to 0.69 in January, and from 0.51 to 0.70 in March, showing improved model skill. The overall analysis of ionospheric scintillation predictions using the ConvGRU model configurations across varied solar activity conditions for the years 2015 (a solar maximum) and 2020 (a solar minimum) provides a deeper understanding of how solar activity influences prediction capabilities in ionospheric scintillation. The FAR index demonstrated a clear decrease from 2015 to 2020 in all models.