Cyclicity of natural processes in the last 300 years imprinted in the Tree-Ring proxies in Subarctic European Russia revealed by wavelet analysis

Abstract

We studied the cyclic structure of the earlywood ring width and maximum density of larch and spruce (International Tree-Ring Data Bank) at the northern treeline in European Russia. On the basis of correlation analyses, local chronologies are combined into seven regional ones. The chronologies of maximum density correlate positively with summer (May–August) temperature. The response functions for the earlywood ring width are chaotic. However, a wavelet analysis of instrumental cold-period (October–April) precipitation series and regional earlywood chronologies shows a similarity in their cyclic pattern. On the basis of a wavelet analysis, it was found that the chronologies of the western and northern regions of European Russia have a similar cyclic structure over the last 300 years, while the Ural chronologies differ from them in some respects. The long-term (40–100 years) variations dominate in the earlywood chronologies, whereas the chronologies of maximum density also contain short-term (5–20 years) variations. The 100- and 11-year cycles, which are probably modulated by solar activity, are detectable in all regional chronologies of earlywood width and maximum density. Cycles with periods of 40, 20–22, and 5 years in the tree-ring chronologies are most likely triggered by the North Atlantic Oscillation, which has a similar cyclic structure.