December 2019 confirmed as starting point of the new solar activity cycle
The reference date and amplitudes of the minima and maxima of the 11-year solar cycle are established on the base of the sunspot number maintained and distributed by the SILSO World Data center since 1981 at the Royal Observatory of Belgium.
Over past years, the rather weak cycle that had peaked in 2014 has been progressively declining, heralding the approach of [...]