Solar modulation during the Holocene
05 Feb 2008
Eawag, Aquatic Science, Surface Waters – Radioactive Tracers, Überlandstrasse 133, 8600 Dübendorf, Switzerland
Abstract. We built a composite of three reconstructions of the solar modulation function over the Holocene. The reconstructions until 1950 are based on data from cosmogenic radionuclides and the present time (1951–2004) on neutron monitor data.
Interpreting our composite as an index of solar activity, we were able to compare the current solar activity with the last 9300 years. During this time span 25 periods with similar high activity than the current period were found. That corresponds to about 15% of the time which lead to the conclusion that currently the Sun is very but not exceptionally active.
Our composite has a large potential for studies dealing with solar activity like the understanding of the solar dynamo and the reconstruction of solar forcing.