The nonlinear character of the effect of solar activity on climatic processes

The effect of solar activity and variability on climatic processes during t he past 300 years has been analyzed based on the growth of tree rings at th e northern treeline at the Kola Peninsula (Russia) and in Scandinavia (Finn ish Laplandia). It has been shown that the periodicity of solar activity (s imilar to 22-23 and 90 years) correlates well with the cyclicity of climati c processes shown in the growth of tree rings. Tree-ring growth also testif ies to the variability of climatic processes with periods of similar to 33 and 18 years. The climatic cyclicity with a period of similar to 35 years i s known as the Bruckner cyclicity. In this work, the generation of the Bruc kner climatic cycle is interpreted as the result of the nonlinear effect of solar activity on atmospheric processes.