The 24th solar cycle: Prelyminary analysis and generalizations

A preliminary comparison of the present solar cycle No24 (SC24) and the previous cycles in relation to large number of "space weather" parameters (sunspot activity, radioindex F-10.7, X-ray flares, solar radiobursts, eruptive protuberances, Sun's polar magnetic fields, geomagnetic AA-index, galactic cosmic rays (GCR) fluxes etc.) is the main subject of this study. The lengths of the used there solar and geophysical data series are depending on the beginning of regular observations. For sunspot activity index R-i it is since 1749, for geomagnetic AA-index -since 1868 AD, while for some of parameters like eruptive protuberances or radiosweeps only data for the last two solar cycles SC23 and SC24 are used. All used data series ends on October, 31, 2017. As is shown in this "express" preliminary analysis SC24 is the weakest solar sunspot cycle at least since sunspot cycle No12 (1879-1889 AD) or (possible) even since SC6 (1810-1823). The "geomagnetic" SC24 is the weakest for the whole AA-index data series, i.e. since 1868 AD. This conclusion is valid for almost all studied parameters- flares, F-10.7, radiobursts etc. It was found that SC24 is positioned on long-term downward trend, which has been started for the most of the solar activity events earlier to the maximum of sunspot cycle No 22 (SC22), namely after 1991 AD. A prediction that the next solar cycle 25 (SC25) will be with almost the same amplitude or slightly stronger than SC24 is given. A possibility for "underdeveloped" SC26 is also discussed. Arguments that the present relatively weak SC24 is connected to the supercenturial and supermillenial solar activity oscillations (200-210 yr "Suess cycle" and 2200-2400 yr "Hallstadtzeit cycle") and for beginning of "Dalton-type" solar grand minimum are given.