Orateur
Dr
Edouard Bard
(CEREGE Aix-en-Provence)
Description
We analyzed phase lags between the 11-year cycles of solar activity (sunspot numbers, SSN), cosmic ray flux (CRF) and 0.5-year oscillations of the length of day (LOD). The analysis is performed for the solar cycles number 20-23 (1965-2010). Phase lags are calculated by using different methods: time lag between maxima of corresponding cycles, according to maximal coefficient of cross-correlation, maximal amplitude of wavelet cross coherence, and as time lag between equivalent momentary phases calculated following the method of 2D-diagrams in phase space. For SSN and CRF time series, these methods allow to document a clear phase difference between odd and even cycles as shown by previous authors (e.g. Nymmik & Suslov 1995 Adv. Space Res. 9, 217; Usoskin et al. 2001 Adv. Space Res. 27, 571). By contrast, the phase lags between SSN and LOD do not show such a clear-cut systematic pattern. We will tentatively discuss the implications of these results for the plausibility of physical mechanisms proposed to link SSN, CRF and LOD.
Auteurs principaux
Dr
E. Bard
(CEREGE UMR-6635, CNRS, Université Aix-Marseille, IRD, Collège de France)
Dr
T. Barlyaeva
(CEREGE Aix-en-Provence)
