Periodicity of climate conditions and solar variability derived from dendrochronological and other palaeoclimatic data in high latitudes

The periodicity of climatic processes in the Barents Sea Region and along the Arctic Ocean coast during several hundred years has been studied by analyzing the tree-ring chronologies for the regions close to the northern timberline. In the Barents Sea region, cyclicities of climatic processes with periods of around 90, 30–35, 22–23, 18 and 11–12 years have been established by spectral analysis of the data for the Kola Peninsula. Wavelet analysis of annual series of conifer tree-rings generalized for 10 regions along the northern timberline, from the Kola Peninsula to Chukotka, for the period 1458–1975 has revealed the same periodicities for the vast areas of northern Russia. Climatic cyclicity with a period of about 35 years is known as the Brückner cycle. Climatic cycles with periods of around 90, 22–23 and 11–12 years correlate well with the corresponding solar activity cycles. A possible solar forcing of periodic climatic processes and its nonlinear influence on the atmosphere–ocean–continental system are discussed.