## 6 Weddell Sea Anomaly
Knowing the main climatological (2002-2022) features of the TEC nonmigrating tides investigated in the present study such tides could be: (i) the zonally symmetric D0, because its recurrent enhancements in the austral summer around latitudes of \(\sim\)60\({}^{\circ}\) S ([PERSON] et al., 2013 [102]); (ii) the DW2 tide that reveals some enhancements in December-January at latitudes of \(\sim\)40\({}^{\circ}\) S; and (iii) the DE1 having some secondary amplification in December-February at latitudes of \(\sim\)65-70\({}^{\circ}\) S. All the above-mentioned nonmigrating tides are with phases maximizing around the local midnight. The SPW1 has a component that also amplifies at latitudes of \(\sim\)60\({}^{\circ}\) S in December. Our result fully supports the previous WSA study reported by [PERSON] et al., 2015 [103]. It is noted above that we are interested in the climatology of the WSA. This means that it is advisable to know in advance the nature of these nonmigrating tides, i.e., whether they are locally generated in the IT system, or are vertically upward-propagating from the lower atmosphere. It has been found before that the locally excited tides are strong during solar maximum ([PERSON] et al., 2013 [95]) while the upward-propagating nonmigrating tides from the lower atmosphere are dominant at solar minimum [104]. If the above-mentioned nonmigrating tides belong to only one of type, then the WSA climatology probably could be under question. To clarify the nature of the considered nonmigrating tides, the F3/C electron density profiles for 2008 are analyzed in the same way as the SABER temperature and TEC data sets. We obtained, for December 2008, the same results as those of [PERSON] et al., 2015 [103], with an exception related to the DW2 tide; we also obtained similar results for December 2011. Figure 15a shows the altitude-latitude structure of the DW2 amplitude (upper plot, in MHz) and phase (bottom plot, in degree) extracted from the FORMOSAT-3/COSMIC electron density profiles. There are two tidal amplifications, and of interest to us (i.e., it may contribute to the WSA production) is that situated around latitudes of (40-50\({}^{\circ}\)) S and altitudes of \(\sim\)180-400 km; its phase structure clearly indicates a vertical upward propagation from below. Figure 15b demonstrates the latitude-time climatological (2002-2022) structure of the TEC DW2 tidal amplitude. In addition to the semiannual variability connected to changes in neutral thermospheric composition, it can be seen also in the DW2 enhancements in December around latitudes of \(-\)40\({}^{\circ}\) and 20-30\({}^{\circ}\), which fully reflects the two amplifications seen in the upper plot of Figure 15a. It is worth noting that Figure 15a,b are obtained from two different data sets, and while Figure 15a presents a concrete observation, Figure 15b is a climatological result based on large statistics. We, however, underline that the result of Figure 15a, indicating that the DW2 seen in the IT system, is vertically upward-propagating from below tide, contradicts not only to that of [PERSON] et al., 2015 [103], but also to previous results based on simulations using the NCAR TIME-GSM [96] or a combination of satellite observations and employing Hough mode extensions (HMEs) and the Climatological Model of Thermosphere Tides (CTMT) [91]. This problem deserves to be more seriously investigated by simultaneous satellite observations of the MLT and IT system (especially the electron density measurements) based on larger statistics. Figure 15: (**a**) Altitude-latitude structure of the DW2 amplitude (**upper** plot, in MHz) and phase (**bottom** plot, in degree) extracted from the FORMOSAT-3/COSMIC electron density profiles, and (**b**) latitude-time climatological structure of the TEC DW2 tidal amplitude. The next step is to make an attempt to reconstruct not only the WSA itself for different local times, but also the global distribution of TEC for December, first presenting the concrete results for December 2008 and then the corresponding climatological ones.