caa a22 4500 445347465 CHVBK 20180317142833.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s11207-011-9802-x doi (NATIONALLICENCE)springer-10.1007/s11207-011-9802-x On Mid-Term Periodicities in Sunspot Groups and Flare Index [Elektronische Daten] [Blanca Mendoza, Víctor Velasco-Herrera] In this work we study the mid-term periodicities (MTPs), between 1 and 2 years, of the sunspot groups and the flare index (FI), by separating the data into hemispheres and spectral bands (SBs) according to the most significant periodicities presented by these phenomena. We found that the MTP of sunspot groups has a diminished power during the Modern Minimum and an increased power during the Modern Maximum, with the exception of cycle20. For flares, the MTP has a diminished power during the low activity cycle20, and an increased power during cycles21 and 22. Therefore, for both sunspot groups and FI, cycle 20 shows a very diminished power followed by the active and higher-power cycles 21 and 22; cycle 23 shows a weaker power than cycles 21 and 22. It is uncertain whether MTP can be a precursor of a long-term minimum of solar activity or not, as has been previously suggested. Also, there is no one-to-one correlation between the cycle intensity and the importance of MTP. Concerning the quasi-biennial periodicities and the theory of two kinds of dynamos, we notice the tendency that higher-power cycles mean weaker coupling in the model. Concerning the hemispheric north-south asymmetry, for sunspot groups the southern hemisphere dominates in most of the SBs, while for FI the northern hemisphere dominates for all the SBs. Additionally, the time lag found between the two hemispheres indicates that the degrees of coupling in the photosphere for sunspot groups and in the corona for flares are between moderate and strong. Finally, the modulation shown by the MTP time series suggests that these periodicities are the product of chaotic quasi-periodic processes and not of stochastic processes. Springer Science+Business Media B.V., 2011 Flare index nationallicence Mid-term periodicities nationallicence North-south asymmetry nationallicence Sunspot groups nationallicence Mendoza Blanca Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510, México DF, CP, Mexico aut Velasco-Herrera Víctor Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510, México DF, CP, Mexico aut Solar Physics Springer Netherlands 271/1-2(2011-07-01), 169-182 0038-0938 271:1-2<169 2011 271 11207 https://doi.org/10.1007/s11207-011-9802-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9802-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mendoza Blanca Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510, México DF, CP, Mexico aut NATIONALLICENCE 700 1- Velasco-Herrera Víctor Instituto de Geofísica, Universidad Nacional Autónoma de México, 04510, México DF, CP, Mexico aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 271/1-2(2011-07-01), 169-182 0038-0938 271:1-2<169 2011 271 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer