Solar cycles: the past evolution influence

Influence of the Tachocline on Solar Evolution

Recently helioseismic observations have revealed the presence of a shear layer at the base of the convective zone related to the transition from differential rotation in the convection zone to almost uniform rotation in the radiative interior, the tachocline. At present, this layer extends only over a few percent of the solar radius and no definitive explanations have been given for this thines...

Solar Flare Cycles

We present a review of different solar flare periodicity intervals. Our analysis includes a statistical investigation of flare occurrence and N-S hemispheric distribution over the last three 11-yr solar cycles (SCs 21-23, corresponding to the period 1976-2001). Moreover, we try to estimate if there is any connection between the flare activity and the strength of solar cycles. For that purpose, ...

Solar Variability and Climate Cycles

Nonlinear analysis of solar cycles

In this paper, the recent improvement of the Wolf sunspot time–series by Hoyt and co-workers has been analysed with the Global Flow Reconstruction (GFR) method (Serre et al. 1996a and b). A nonlinear 4–dimensional chaotic model has been extracted from the data which captures the principal characteristic features of the sunspot group time–series. The hypothesis of interactions between magnetic m...

Solar Variability and Climate Cycles