Comparison of radionuclide-based solar reconstructions and sunspot observation the last 2000 years

Abstract: The sun is an important reason to why there is life on earth. To be able to predict future solar activity it is important to uncover past solar activity and its cyclicity. This thesis investigates the solar activity throughout the past 2000-years to the beginning of 21th century. Diagrams which contain relevant data from radionuclide and sunspot records have been constructed to get a better overview of solar activity variations during the investigated period. They show a trend of increasing span in solar maxima and minima from year 0 to present. Correlation analysis between radionuclide records and naked sunspot number (sunspot archives) resulted in bad correlation. This in contrast to the results when radionuclide records were correlated to GSN (Group sunspot numbers) data based on telescope observations, which resulted in a better correlation. The conclusion is the naked eye sunspot record is very difficult to use as a primary source for estimating past solar activity, apart from a few periods with a high amount of observations.