Ilya Usoskin

NameIlya Usoskin
AffiliationUniversity of Oulu, Finland
TitleLong-term variations of solar activity
AuthorsIlya Usoskin
AbstractSolar activity is dominated by the 11-yr Schwabe cycle but it varies also on long-term scales. Direct solar observations are available for the last 400 years but their quality before 1900 is poor. Indirect proxy data based on cosmogenic isotopes let us study solar variability on a time scales of ten-thousand years. A brief overview of the current state of the art in the field of solar variability on different times scales is presented. It is discussed that solar activity is a non-periodic and non-stationary process.