Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1778098 | Journal of Atmospheric and Solar-Terrestrial Physics | 2008 | 9 Pages |
Abstract
A tree-ring thickness time series from Passo Fundo (Southern Brazil) for the interval 1741-2004 was studied by spectral, wavelet and cross-wavelet analyses in order to identify the non-stationary characteristics in tree-ring and sunspot number data. Periods corresponding to the solar cycles of 11, 22, and 80Â yr were found. The 11Â yr solar cycle is detected in tree-ring data only during maximum solar activity interval from 1764 to 1804, 1824 to 1884, and 1924 to 1984. The Hale 22Â yr solar cycle was observed in tree-ring wavelet map for the 1764-1864 and 1904-2004 intervals. The Gleissberg solar cycle was also observed in tree-ring wavelet map for the 1844-1904 interval.
Keywords
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Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
N.R. Rigozo, A. Prestes, D.J.R. Nordemann, H.E. da Silva, M.P. Souza Echer, E. Echer,