## 7 Summary  
This paper presents the climatological features of the longitudinal structures WN4, WN3, and WN2 observed both in the lower thermospheric temperatures and in the ionospheric TEC observations. For this purpose, two long-term data sets are utilized: the satellite SABER/TIMED temperature measurements, and the global TEC maps generated with the NASA JPL Ionosphere Center for the interval of 2002-2022. The large statistics used in this study, based on 21 full years of observations, allows us to determine the spatial distribution and seasonal variability of the above-mentioned longitude structures with a high degree of probability. The investigated WN4, WN3, and WN2 structures are produced by nonmigrating tides and zonally propagating planetary waves. Therefore, this study first investigates the climatological features of those nonmigrating tides, which are the main drivers of the above-mentioned longitude structures; these are the nonmigrating diurnal DE3, DE2, and DW2, and the semidiurnal SW4 and SE2 tides. The climatology of their spatial distribution, as well as the seasonal and interannual variability of the mentioned tides, are investigated in Section 3. Their climatological latitude and altitude-latitude structures, presented in Figures 1 and 5, revealed that all these tides are vertically upward propagating and reach the largest amplitudes at or slightly above 110 km height. The main seasonal components for all nonmigrating tides under consideration turned out to be their annual means and annual and semiannual components. Their latitude-time structures, displayed in Figures 3 and 7, demonstrate well evident interannual variations. Particular attention is paid to the stratospheric QBO index at 30 hPa; its impact on the seasonal components is studied using a cross correlation analysis. The seasonal components of the considered diurnal and semidiurnal nonmigrating tides in the lower thermosphere exhibit significant QBO variability, particularly the diurnal DE3 and DE2 tides (Figures 4 and 8). The impact of the solar cycle has been investigated as well, but, in general, its effect on the considered nonmigrating tides is weak. The climatological (2002-2022) features of the longitudinal WN4, WN3, and WN2 structures in the lower thermosphere (altitude of 110 km) are studied in detail in Section 4. The result for the WN4 (Figure 9) supports the previous ones, obtained on far smaller statistics, being that this is the strongest longitudinal structure in the lower thermosphere. We find that its largest climatological magnitude is \(\sim\)20 K observed at 10\({}^{\circ}\) S in August. Additionally, the WN4 has larger magnitude in the SH than that in the NH, but only at latitudinal range of \(\pm\)30\({}^{\circ}\). The WN2 (Figure 11) is the second strongest structure, with magnitude reaching up to \(\sim\)13.9 K at latitudes of 10\({}^{\circ}\) S in February; this structure demonstrates clear hemispheric asymmetry, as the SH structure is stronger than the NH one at the entire latitude range (\(\pm\)50\({}^{\circ}\)). The WN3 (Figure 10) is the weakest structure, with the largest magnitude of 12.4 K observed over the equator in July; this structure did not reveal clear hemispheric asymmetry. Besides the hemispheric asymmetry, latitude-seasonal, and some LT dependences, the above results are also supplemented with the assessment the latitudinal dependence of the contribution of each wave component in the production of the considered longitude structure. The climatological features of the respective ionospheric longitudinal structures, presented in such a way as they are present in the global TEC maps, are examined in Section 5. The main reason for such approach is that these structures are able to be quickly recognized among the other ionospheric variations.