Characteristics of Large-Scale Traveling Ionospheric Disturbances During the 10 May 2024 Geomagnetic Storm

Abstract

Based on the total electron content (TEC) observation in the Asian-Australian and American sectors, this paper investigates the characteristics and hemispheric asymmetry of large-scale traveling ionospheric disturbances (LSTIDs) during the 10 May 2024 superstorm. We found that the amplitudes and meridional phase velocities of LSTIDs in the two sectors were greater in the southern hemisphere compared to the northern hemisphere. The energy deposition patterns in both hemispheres, as derived from the polar cap indices and magnetometer data in the two sectors, exhibited a similar hemispheric asymmetry, implying that the differences in energy injection might influence the asymmetric propagation characteristics of LSTIDs. Further investigation into the influence of horizontal neutral winds on LSTIDs variation suggested that southern hemisphere winds may have facilitated LSTIDs propagation, while winds in the Northern Hemisphere might have had a suppressive effect. The observed changes in the O/N2 ratio may partially explain the sectoral differences in the amplitude of LSTIDs between the Northern and Southern Hemispheres. During the geomagnetic storm, the O/N2 ratio in the Asian-Australian sector increased significantly, intensifying the hemispherical disparities, while the American sector exhibited a weaker asymmetry. In conclusion, this study highlights the significant impacts of energy deposition, thermospheric dynamics, and thermospheric composition on LSTIDs behavior during intense geomagnetic storms, unveiling the complex interactions between intense geomagnetic activities and ionosphere in different regions.