Zurich Sunspot Slide Set

Educational Slide Set - Sunspots and Related Solar Phenomena

Portrait of R. Wolf

The Data Center offers a set of 7 slides illustrating different sunspot related phenomena. All slides have captions. The slide set includes:

  • Plotted Annual Mean Sunspot Numbers, 1700-1995. The annual mean sunspot numbers clearly show the sunspot cycle's rise and fall about every 11.1 years.
  • Plotted Monthly Mean Sunspot Numbers, Jan 1749-Apr 1996. Monthly means reveal the sunspot count's variability.
  • Plotted Smoothed Monthly Sunspot Numbers, Jul 1749-Oct 1995. These are an average of two adjacent 12-month running means of monthly means.
  • Plots of Sunspots, Solar Flares, aa Indices. Different indices produce different views of the sun's activity cycle, and this slide illustrates how various solar phenomena can track the sunspot cycle.
  • Total Solar Irradiance. Total solar irradiance measures the sunlight falling each second on 1 square meter of surface area above our atmosphere. Solar irradiance measurements have important consequences in the Earth's "energy budget".

The slide set also includes historical photographs:

  • Johann Rudolph Wolf. Wolf, in 1848, devised a daily method of estimating solar activity by counting the number of individual spots on the face of the sun.
  • Swiss Federal Observatory, 1905. From the beginning of the sunspot number index until the end of 1980, the Swiss Federal Observatory in Zurich served as coordinating office for an international network of dedicated solar observers.

For more information about ordering this, or any of our other slide sets, click here.

Go to Sun Spot numbers page