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Advances in Astronomy
Volume 2012 (2012), Article ID 691408, 11 pages
http://dx.doi.org/10.1155/2012/691408
Research Article

Thirty-Year Periodicity of Cosmic Rays

1Instituto de Geofísica, Universidad Nacional Autónoma de México, C.U., 04510 Coyoacán, DF, Mexico
2International Academy for Appraisal and Consulting (MAOK), Moscow, Russia
3IZMIRAN, Academy of Sciences of Russia, Troitsk, Moscow 142092, Russia

Received 6 September 2012; Accepted 27 October 2012

Academic Editor: Karel Kudela

Copyright © 2012 Jorge Pérez-Peraza et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Cosmogenic isotopes have frequently been employed as proxies of ancient cosmic ray fluxes. On the basis of periodicities of the 10Be time series (using data from both the South and North Poles) and the 14C time series (with data from Intercal-98), we offer evidence of the existence of cosmic ray fluctuations with a periodicity of around 30 years. Results were obtained by using the wavelet transformation spectral technique, signal reconstruction by autoregressive spectral analysis (ARMA), and the Lomb-Scargle periodogram method. This 30-year periodicity seems to be significant in nature because several solar and climatic indexes exhibit the same modulation, which may indicate that the 30-year frequency of cosmic rays is probably a modulator agent for terrestrial phenomena, reflecting the control source, namely, solar activity.