RUSSIAN JOURNAL OF EARTH SCIENCES, VOL. 19, ES1005, doi:10.2205/2019ES000650, 2019 ![]() Figure 3. Yearly mean sunspot number (black) up to 1749 and monthly 13-month smoothed sunspot number (blue) in 1749–2017, http://www.sidc.be/silso/yearlyssnplot. The maxima of the primary solar cycles rise and fall in somewhat cyclical manner known as the secondary solar cycles. Copyright 2019 by the Geophysical Center RAS. Generated from LaTeX source by ELXpaper, v.2.0 software package. |