Statistical study of ICMEs and their geoeffectiveness during the rising phases of Solar Cycles 23, 24, and 25

As Solar Cycle 25 appears to approach the declining phase, to objectively evaluate the activity intensity during its rising phase and conduct a comparative analysis, we extend the catalog of Interplanetary Coronal Mass Ejections (ICMEs) from 2016 to 2025. Subsequently, we systematically compare and analyze the parameter characteristics and geoeffectiveness of ICMEs during the rising phase of Solar Cycle 25 with those of the previous two solar cycles. Overall, from 1995 to 2025, we identify 657 ICME events, which are classified into 530 groups and are associated with a total of 325 geomagnetic storms, including 103 intense geomagnetic storms. The annual occurrence frequencies of ICMEs, the number of ICME groups and their associated geomagnetic storms are largely synchronized with the variations in sunspot numbers. The sunspot numbers during the rising phase of Solar Cycle 25 are comparable to those of Solar Cycle 23 and clearly higher than those of Solar Cycle 24. Compared with the previous two solar cycles, Solar Cycle 25 exhibits the smallest number of ICMEs during its rising phase. The numbers of geomagnetic storms and intense geomagnetic storms during this period fall between those of the two preceding cycles, consistent with the overall variation in solar activity. Although the number of intense geomagnetic storms during the rising phase of Solar Cycle 25 is relatively small, their intensities are remarkably high, with several extremely intense storm events observed. During the rising phase of Solar Cycle 25, the average values of the magnetic field strength, southward magnetic field component, and dawn–dusk electric field of ICMEs are the highest among the three periods. They are key parameters influencing the geoeffectiveness of ICMEs. Overall, the geoeffectiveness of ICMEs during the rising phase of Solar Cycle 25 is intermediate between those of the previous two cycles.