13 papers
Solar Cycle Variation of the Solar Internal Rotation: Helioseismic Inversion and Dynamo Modelling
S. Vorontsov, R. Tavakol, E. Covas +1
We report our first results on comparing the variations of the solar internal rotation with solar activity, as predicted by non-linear solar dynamo modelling, with helioseismic mea…
Crisis-induced intermittency due to attractor-widening in a buoyancy-driven solar dynamo
Eurico Covas, Mathieu Ossendrijver
In a recent paper [M. A. J. H. Ossendrijver, A&A {\bf 359}, 364 (2000)] numerical simulations of a 2D mean--field model where shown to produce grand minima, typical of the long-ter…
Aspects of the dynamics underlying solar and stellar dynamo models
Reza Tavakol, Eurico Covas
Observations of the Sun and solar-type stars continue to reveal phenomena whose understanding is very likely to require a nonlinear framework. Here we shall concentrate on two such…
Spatiotemporal fragmentation as a mechanism for different dynamical modes of behaviour in the solar convection zone
Eurico Covas, Reza Tavakol, David Moss
Recent analyses of the helioseismic observations indicate that the previously observed surface torsional oscillations with periods of about 11 years extend significantly downwards…
Torsional oscillations in the solar convection zone
Eurico Covas, Reza Tavakol, David Moss +1
Recent analysis of the helioseismic observations indicate that the previously observed surface torsional oscillations extend significantly downwards into the solar convection zone.…
Absence of supersensitivity to small input signals in generalized on--off systems
Eurico Covas, Reza Tavakol
It has recently been shown that nonlinear skew product dynamical systems with invariant subspaces which are capable of displaying on-off intermittency can show supersensitivity to…