Solar activity cycles and grand minima occurrence
Résumé
Sunspot number reconstructions (SNRs) based on dendrochronologicallydated radiocarbon concentrations are analyzed through the Empirical ModeDecomposition (EMD) to provide a deeper characterization of the solaractivity long-term periodicities and to investigate the role of theGleissberg and Suess cycles in the grand minima occurrence. TheGleissberg and Suess cycles, with timescales of 60-120 yr and 200-300 yrrespectively, represent the most energetic contribution in SNR records.The EMD approach reveals that these cycles are characterized by multiplescales of variation and that the grand minima sequence is produced bythe coupling between Gleissberg and Suess cycles, the latter beingresponsible for the most intense and longest Spörer-like minima, withtypical duration longer than 80 yr.
Domaines
Astrophysique [astro-ph]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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