Unravelling Rieger and Quasi-Biennial Periodic Trends and Asymmetries in Coronal Mass Ejections Using Wavelet Analysis

Abstract In this study, we investigate the periodic behavior of coronal mass ejections (CMEs) using statistical and wavelet analysis based on the Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph (SOHO/LASCO, 1996 – 2024) and the Solar Eruptive Event Detection System (SEEDS, 1996 – 2022) catalogs. We classified CMEs into angular width–speed (cluster I) and width–acceleration (cluster II), subdivided by latitude and hemisphere to analyze their relative occurrence rates, waiting times, Rieger-type periodicities, and quasi-biennial oscillations (QBOs) across Solar Cycles (SC) 23 – 24. We found that relatively more narrow CMEs occur during declining and minimum phases, while regular and partial/halo CMEs show consistency with the SC activity phase. SEEDS shows a larger fraction of narrow CMEs (≈ 72%) than SOHO/LASCO (≈ 45%), indicating catalog-dependent sensitivity to faint and small-scale eruptions. Furthermore, waiting times for narrow and regular CMEs are relatively longer (shorter) during the maximum (minimum) of SC 23(24), due to weaker polar fields and enhanced CME escape in the weaker SCs. Also, low-latitude CMEs dominate over high-latitude ones in both hemispheres, but the hemispheric asymmetry reverses between SCs. Thus, SOHO/LASCO low-latitude CMEs show southern (northern) dominance in SC 23(24). In contrast, SEEDS exhibits opposite low-latitude dominance in SC 23 but converges to northern dominance in SC 24. Again, high-latitude CMEs exhibit high northern dominance in SC 24, characterized by larger short-term variability and weaker correlation with sunspot number (SSN) in both catalogs. Moreover, Rieger-type periods (≈ 3.7 – 6.4 months) and QBO signals at 1.3 – 2.73 yr tend to repeat across specific latitudes and CME clusters with identical ≈ 2.73 yr periods in both catalogs. Additionally, Rieger-type periods weaken toward higher latitudes and generally last longer in SEEDS than in SOHO/LASCO (including an anomalous long high-latitude southern period in SC 24). Finally, Rieger-type periodicities decrease with increasing CME size in SOHO/LASCO decelerating CMEs, while QBOs increase with CME size.