INTERPLANETARY CHARACTERISTICS AND GEOEFFECTIVENESS DURING RECURRENT GEOMAGNETIC ACTIVITIESOF THE SOLAR CYCLES 23 AND 24

Recurrent geomagnetic activity represents an important component of solar-terrestrial interactions and is mainly associated with high-speed solar wind streams originating from long-lived coronal holes. This study aims to investigate the interplanetary characteristics and geoeffectiveness of this type of activity observed during solar cycles 23 and 24 (1996-2019). Twenty-eight (28) recurrent geomagnetic events were identified using the Aa index and the Sudden Storm Commencement (SSC) dates. Solar wind parameters (speed, proton density, dynamic pressure, and IMF Bz component) and the Dst index were investigated through individual-event analysis, Superposed Epoch Analysis (SEA), and correlation analysis. The individual-event analysis showed that 26 of the 28 events share common interplanetary signatures that are consistently reproduced by the SEA composite profiles. These analyses reveal the typical SIR/CIR signature, characterized by a progressive increase in solar wind speed, early enhancements in proton density and dynamic pressure, recurrent southward IMF Bz intervals, and a decrease in Dst reaching weak-to-moderate storm levels.Correlation analyses further highlight the temporal relationships between interplanetary parameters and geomagnetic activity: solar wind speed acts as a precursor of geomagnetic activity, while the IMF Bz component has a more direct influence on the development of geomagnetic storms through the reconnection phenomenon. Proton density and dynamic pressure modulate the intensity of the magnetospheric response during the principal phase.