The Best Sunspot Cycle Ideas. The source data are the revised international sunspot numbers (isn v2.0), as available at silso. Although observations of solar activity (sunspots) cover.
Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay. Web the number of visible sunspots varies according to a sunspot cycle that averages 11 years in length. The beginning of a solar cycle is a solar minimum , or when the sun has the least sunspots.
