Velocity-dependent CME–sunspot correlations: A multi-scale statistical analysis across Solar Cycles 23–25

Coronal mass ejections (CMEs) are among the most energetic manifestations of solar activity, and their relationship with sunspot number (SSN) — a standard proxy of magnetic variability — is central to space weather forecasting. Earlier studies identified correlations between CME occurrence and SSN but often relied on heterogeneous event samples and coarse temporal averaging. Here we present a systematic statistical analysis of CME occurrence rates and SSN spanning Solar Cycles 23–25 (January 1996–September 2025). Our approach combines velocity-based population stratification accounting for measurement uncertainties, non-parametric correlation analysis with bootstrap confidence intervals, and multi-scale temporal evaluation at annual and monthly resolutions. Results show that CME–sunspot coupling depends strongly on both velocity regime and temporal scale. At the annual scale, moderate-to-fast CMEs (600–1500 km s − 1 ) display the strongest correlations with SSN ( ρ ≈ 0 . 93 –0.97), despite comprising only about 12% of events, indicating that long-term solar-cycle evolution mainly controls the occurrence of energetic eruptions from magnetically complex active regions. In contrast, monthly correlations are stronger for slow and moderate CMEs, especially during the weaker Solar Cycle 24 ( ρ ≈ 0 . 90 for slow events), suggesting that short-term solar variability influences different CME populations in distinct ways. These results demonstrate that CME–sunspot coupling varies with both temporal resolution and event population, and provide a statistically grounded framework for converting sunspot-based solar-cycle forecasts into velocity-resolved CME occurrence predictions, thereby improving tools for space weather prediction.