# A High Latitude Model for the E Layer Dominated Ionosphere
## 5 Model Validation  
In this section, we give the results of validating our models with the test dataset. In this regard, we again show trends for the original model observable values (red) and for those as predicted by our models (black). Furthermore, we show the resulting RMS and NRMS values and compare them with the corresponding values presented in Section 4 for the modeling dataset. Figure 6 shows the results of validating our \(NmE\) model NEEM-N with the test dataset. Figure 6: Observed (red) and predicted (black) NmE trends for the test dataset. (**Left**) Northern Hemisphere. (**Right**) Southern Hemisphere. Last row: RMS and NRMS deviation between observation and prediction. For the Northern Hemisphere, we find an NRMS of 36.1% for the modeling dataset, while this value is slightly increased to 36.3% for the test dataset. For the Southern Hemisphere, the NRMS for the test dataset is 46.9%. This value is slightly lower than the NRMS for the modeling data set, which is 47.1%. Figure 7 shows the results of validating our \(hmE\) model NEEM-H with the test dataset. When comparing the Northern Hemisphere NRMS results for the modeling dataset with those for the test dataset, we find that the NRMS is 6.1 and 6.2%, respectively. For the Southern Hemisphere, we have the same NRMS of 6.3% for both datasets. Figure 8 shows the validation results for the \(wvE\) model NEEM-W after applying it to the test dataset. Figure 7: Observed (red) and predicted (black) hmE trends for the test dataset. (**Left**) Northern Hemisphere. (**Right**) Southern Hemisphere. Last row: RMS and NRMS deviation between observation and prediction. By comparing the NRMS results, we see that for the Northern Hemisphere, we have a value of 38.6% for the modeling dataset, while this value is slightly decreased to 38.5% for the test dataset. In the case of the Southern Hemisphere, the NRMS for the two datasets is 41.0 and 41.1%, respectively. With a share of only 1/10 th of the full electron density profile dataset, the test dataset is much smaller than the modeling dataset. Consequently, for the qualitative validation of the %\(ELDI\) model, it was necessary to adjust the interval key formation in such a way that a sufficiently large number of valid keys remain. Therefore, we reduced the threshold for the minimum number of assigned profiles required by each valid key to 50, resulting in a %\(ELDI\) resolution of 2%. In addition, we reduced the number of intervals to four for the model drivers _MLAT_, _LT_ and _DOY_. Table 7 shows the corresponding statistical information about the interval keys generated for both hemispheres. Figure 8: Observed (red) and predicted (black) wvE trends for the test dataset. (**Left**) Northern Hemisphere. (**Right**) Southern Hemisphere. Last row: RMS and NRMS deviation between observation and prediction. In Figure 9, we show the results of validating our \(\%ELDI\) model NEEM-P with the test dataset. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Quantity** & **North** & **South** \\ \hline Mathematically possible number of keys & \(576\) & \(576\) \\ Number of keys with less than 50 profiles & \(118\) & \(120\) \\ Number of keys used for fitting & \(458\) & \(456\) \\ Minimum number of profiles per key & \(50\) & \(50\) \\ Maximum number of profiles per key & \(131\) & \(130\) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Statistical information about the interval keys of the test dataset for the Northern and Southern Hemispheres. Figure 9: Observed (red) and predicted (black) \(\%ELDI\) trends for the test dataset. (**Left**) Northern Hemisphere. (**Right**) Southern Hemisphere. Last row: RMS and NRMS deviation between observation and prediction. Regarding the NRMS for the Northern Hemisphere, we see a minor increase from 56.5% for the modeling dataset to 57.4% for the test dataset. For the Southern Hemisphere, we observe an increase from 58.7 to 60.3%.