Distinct Impacts of the Extreme Space Weather Events of 2024 on the Low Latitude Ionospheric Dynamics in the Indian Sector as Captured by Combined Space and Ground Based Plasma Measurements

Abstract Two extreme space weather events that occurred in May and October 2024 triggered severe modifications in the geospace environment leading to super geomagnetic storms of class G5 and G4, respectively. These two events that occurred in the increasing phase of the current 25th solar cycle during different seasons provided a unique opportunity to investigate the distinct nature of storm induced impacts on the ionospheric dynamics and electron density distribution, especially with regard to their seasonal dependence. The behavior of Equatorial Ionization Anomaly during these two superstorms has been explored in detail using Total Electron Content (TEC), digisonde, and satellite based measurements in the Indian low latitude sector. Ionospheric TEC variations during the recovery phase of the May storm revealed strong positive enhancement near the equator due to the suppressed fountain effect with a negative storm effect at the low latitudes. In the recovery phase of the October storm, a negative storm effect is seen over the low latitudes. The responses of the bottom side and top side of the ionosphere to the storm induced disturbances have shown distinct differences with respect to the magnitudes of deviations and settling times. The relative dominance of prompt penetration and disturbance dynamo electric fields and thermospheric composition changes on the observed modifications of ionospheric dynamics during these two storms are discussed. This study provides crucial information on the distinct impacts of two severe geomagnetic storms under varying seasonal background conditions over the equatorial and low latitude sectors.