# Effects of the October 2024 Storm over the Global Ionosphere
## 4 Results
### Storm Effects on Swarm Observation
06:00 to 15:00 UT on 6 October, the EIA observed by Swarm A remains concentrated within \(\pm\)15\({}^{\circ}\) latitudes over the Asian-Australian sectors. After 15:00 UT on 6 October, ionospheric behaviour returns to patterns similar to those observed on 5 October. During the initial hours of the storm, Swarm A and B did not show significant global Ne depletions immediately following the SSC at 15:16 UT. However, as the main phase of the storm developed, Swarm A observed a notable Ne depletion (-3.2 \(\times\) 10\({}^{6}\) electrons/cc) across the Afro-European sector and increased variability over the Pacific. Swarm B recorded ionospheric perturbations over both North and South American sectors. When compared to quiet-day Swarm observations on 5 October, storm-time data clearly demonstrated an expansion of the EIA, particularly over the Southern Hemisphere of the Afro-European and American longitudes. [PERSON] et al. (2025) [PERSON] et al. (2025) reported a similar expansion between longitudes \(-\)50\({}^{\circ}\) and \(-\)130\({}^{\circ}\) around 18:00 UT, which corresponds well with our findings in Figure 10f. Notably, over Africa, Swarm B detected a sharp Ne depletion, indicative of strong upward plasma drift, validated by a pronounced depletion in the corresponding Madrigal TEC map at 21:40 UT (Figure 10). These results reinforce findings from Figure 4, an F-region uplift--now confirmed by Swarm data. Figure 11: (**a–t**) Three-hour global tracks of Swarm Ne (Swarm A represented by brown tracks and Swarm B represented by blue tracks). The leftmost column represents the Swarm tracks from 06:00 UT to 21:00 UT on 6 October, a geomagnetically quiet period for reference. The second column depicts the storm-time Swarm tracks from 06:00 UT to 21:00 UT on 11 October. The third and fourth columns represent the madrigal global TEC maps during the geomagnetically quiet and disturbed periods. Between 00:00 and 06:00 UT on 11 October, the storm reached its peak intensity. During this period, Swarm B data revealed that the EIA expanded from \(\sim\)45\({}^{\circ}\)N to \(\sim\)60\({}^{\circ}\)S, especially on the dayside, with more limited expansion on the nightside. Plasma uplift was strongest between 30\({}^{\circ}\)N and 45\({}^{\circ}\)S, particularly evident in Swarm B (Figure 10n). At 00:20 UT on 11 October, TEC maps from Madrigal revealed a distorted \"C\"-shaped EIA crest in both Hemispheres (Figure 10p), similar to observations reported by [PERSON] et al. (2025) [18], who attributed this reversed C-shaped structure to enhanced vertical and zonal drifts, driving the expansion of polar irregularities to midlatitudes and merging with equatorward-propagating EPB structures. Between 03:00 and 06:00 UT, poleward expansion of the EIA gradually subsided on the dayside, while plasma uplift remained active from 45\({}^{\circ}\)N to 45\({}^{\circ}\)S, especially in the nightside equatorial sector. This continued uplift is consistent with higher hmF2 values observed in Figure 4 over the African and American longitude sectors. Figure 11a-t extends this analysis to 06:00-21:00 UT on 11 October, capturing the storm's recovery phase. From 06:00 to 09:00 UT, the Northern Hemisphere exhibited an expansion of the nightside EIA from 30\({}^{\circ}\)N to 45\({}^{\circ}\)N, while the Southern Hemisphere displayed a contraction of the EIA. Simultaneously, Swarm B detected a significant dayside Ne depletion over the American and Pacific sectors, aligning with earlier hmF2 observations (Figure 4c). From 09:00 to 15:00 UT, this pattern persisted--nightside contraction in the South and dayside expansion remained evident but weakened. Notably, between 12:00 and 15:00 UT, Ne depletion was sustained over the equatorial dayside Southern Hemisphere, confirmed by Swarm B (Figure 11j). [PERSON] et al. (2025) [18] observed similar features, attributing them to a second uplift phase driven by DDEFs, with F-region heights reaching \(\sim\)410 km over Sao Luis and \(\sim\)450 km over Jicamarca between 08:00 and 09:00 UT.