TY JOUR TI Long-term solar activity variations as a stimulator of abrupt climate change KW solar activity variations KW abrupt climate change KW ice-rafting events. JO Russian Journal of Earth Sciences AU Raspopov, O.M. AU Dergachev, A.V. AU Kolstrom, T.. AU Kuzmin, A.V. AU Lopatin, E.V. AU Lisitsyna, O.V. PY 2007 IS 9 PB Geophysical Center of the Russian Academy of Sciences