North-south asymmetry in small and large sunspot group activity and violation of even-odd solar cycle rule

Abstract

According to Gnevyshev-Ohl (G-O) rule an odd-numbered cycle is stronger than its preceding even-numbered cycle. In the modern time the cycle pair (22, 23) violated this rule. By using the combined Greenwich Photoheliographic Results (GPR) and Solar Optical Observing Network (SOON) sunspot group data during the period 1874-2015, and Debrecen Photoheliographic Data (DPD) of sunspot groups during the period 1974-2015, here we have found that the solar cycle pair (22, 23) violated the G-O rule because, besides during cycle 23 a large deficiency of small sunspot groups in both the northern and the southern hemispheres, during cycle 22 a large abundance of small sunspot groups in the southern hemisphere. In the case of large and small sunspot groups the cycle pair (22, 23) violated the G-O rule in the northern and southern hemispheres, respectively, suggesting the north-south asymmetry in solar activity has a significant contribution in the violation of G-O rule. The amplitude of solar cycle 24 is smaller than that of solar cycle 23. However, Coronal Mass Ejections (CMEs) rate in the rising phases of the cycles 23 and 24 are almost same (even slightly large in cycle 24). From both the SOON and the DPD sunspot group data here we have also found that on the average the ratio of the number (counts) of large sunspot groups to the number of small sunspot groups is larger in the rising phase of cycle 24 than that in the corresponding phase of cycle 23. We suggest this could be a potential reason for the aforesaid discrepancy in the CME rates during the rising phases of cycles 23 and 24. These results have significant implication on solar cycle mechanism

9 pages, 9 figures, accepted for publication in Astrophysics and Space Science

References in corpus (6)

• The Solar Cycle
• The Peculiar Behavior of Halo Coronal Mass Ejections in Solar Cycle 24
• North-south asymmetry in solar activity: predicting the amplitude of the next solar cycle
• Long-term variations in the correlation between NAO and solar activity: the importance of North-South solar activity asymmetry for atmospheric circulation
• Long-term variations in the north-south asymmetry of solar activity and solar cycle prediction, III: prediction for the amplitude of solar cycle 25
• Long-Term Variations in the Growth and Decay Rates of Sunspot Groups

Cited by in corpus (8)

• Sunspot Sizes and The Solar Cycle: Analysis Using Kodaikanal White-light Digitized Data
• Will Solar Cycles 25 and 26 Be Weaker than Cycle 24 ?
• The spatial distribution of quasi-biennial oscillations in the high-latitude solar activity
• North--South Asymmetry in Solar Activity and Solar Cycle Prediction, IV: Prediction for Lengths of Upcoming Solar Cycles
• Variation in solar differential rotation and activity in the period 1964-2016 determined by the Kanzelhöhe data set
• Comparison of the shape and temporal evolution of even and odd solar cycles
• Comparison of Latitude Distribution and Evolution of Even and Odd Sunspot Cycles
• North-South Distribution and Asymmetry of GOES SXR Flares during Solar Cycle 24