solar space index-201001

In 1843, German astronomer Samuel Heinrich Schwabe discovered for the first time that the number of sunspots had a periodic variation of about 11 years through daily observations of sunspots between 1826 and 1843. The period with the highest sunspot activity during this cycle is called the maximum period, and the period with the lowest sunspot activity is called the minimum period.

The intrinsic reason is that sunspots are regions with strong magnetic fields, and their 11 year periodic changes directly reflect the periodic evolution of the solar magnetic field. The rapid release of solar magnetic field energy triggers solar flares, coronal mass ejections, and other solar eruption activities. As people gradually understand and master these explosive activities, it is found that the frequency and strength of these explosive activities also have a periodicity of about 11 years.