## 3 Results
### Statistical Comparison against ISRs Data
The figure highlights how the \(T_{\rm e}\) spatial distribution follows the configuration of the Earth's magnetic field lines. In fact, the characteristic shape of the magnetic equator and of the auroral regions stand out, and this is somewhat expected because the plasma in the topside ionosphere is generally constrained by the geomagnetic field ([PERSON] _et al._, 2016). This behavior has also been recently confirmed by [PERSON] et al. (2017, 2018) that, by using Swarm data, identified patterns in the parallel electrical conductivity (which is crucially affected by \(T_{\rm e}\)) related to features of the geomagnetic field such as regions R1 and R2 ([PERSON] _et al._, 2018) or the magnetic cusp ([PERSON] _et al._, 2018). They also identified variations in the parallel electrical conductivity due to MLT, QD latitude, season, solar, and geomagnetic activity. The MLTs around dawn highlight the fact that the morning peak is a phenomenon affecting only the low latitudes, which follows the magnetic equator shape and reinforces in the longitudinal sector between \(80^{\circ}\)W and \(80^{\circ}\)E (including South America and Africa) where the departure between the magnetic equator and the geographic one is the largest. At the morning peak, Swarm B values exceed 3000 K in many longitudinal sectors, well above those recorded at mid latitudes and even higher than high latitude ones. In contrast, during daytime and nighttime, the high latitudes experience the highest values; in both cases, the increase of \(T_{\rm e}\) from mid to high latitudes is limited to a quite narrow latitudinal range where the spatial gradient is concentrated: at mid latitudes during daytime and at the sub-auroral and auroral boundaries during nighttime. When compared to IRI-modeled values, the largest differences emerge at magnetic equator latitudes at dawn, and at low and mid latitudes during daytime and nighttime, respectively. Overall, Swarm measurements exceed IRI values for most cases and this is in line with the results of Figures 2 and 3. The excess is particularly clear at the morning peak and at low and mid latitudes at nighttime. If we recall the analysis shown in the previous section, based on the comparison with ISRs data (Figures 4-6), we can say that Swarm overestimates the nighttime values; at the morning peak, Jicamarca ISR results (Figure 4) point out that the difference between Swarm and IRI is mainly due to a joint action of both the Swarm overestimation and the IRI underestimation. As highlighted by Figure 7, the Earth's magnetic field has a strong influence on the diurnal trend of Swarm and IRI values. Therefore, we binned \(T_{\rm e}\) data also as a function of QD latitude and MLT with bins 2.5\({}^{\circ}\)-wide and 15 minutes-wide, respectively. The binning was first performed on the entire dataset and then by selecting different days of the year representative of the March equinox, June solstice, September equinox, and December solstice conditions, as done in Section 3.2. for ISRs data. Figure 8 shows that the overall diurnal trend of \(T_{\rm e}\) is characterized by different well-defined features at different latitudes. At low latitudes, the morning peak is the main feature and small day-night differences are visible, which confirms the results from Dicamarca ISR (Figure 4). At mid latitudes (30-60\({}^{\circ}\) QD latitude), no distinct morning peak is present and the main feature is the remarkable difference of absolute values between daytime and nighttime, which confirms the results from Millstone Hill ISR (Figure 6). At high latitudes, the diurnal trend is less pronounced with high values throughout the day that intensify during daytime at the auroral boundaries. The agreement between Swarm and IRI is very good for what concerns the overall diurnal pattern. The main differences characterize the morning peak hours and the nighttime hours for low and mid latitudes.