activity
19972000
collaborators

6 papers

astro-ph2000

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.…

astro-ph1998

The influence of geometry and topology on axisymmetric mean-field dynamos

E. Covas, R. Tavakol, A. Tworkowski +3

We study the changes in the dynamical behaviour of axisymmetric spherical mean-field dynamo models produced by changes in their geometry and topology, by considering a two paramete…

astro-ph1998

Mean Field Dynamos with Algebraic and Dynamic alpha-Quenchings

A. Tworkowski, E. Covas, R. Tavakol +1

Calculations for mean field dynamo models (in both full spheres and spherical shells), with both algebraic and dynamic --quenchings, show qualitative as well as quantitative dif…

chao-dyn1998

In-out intermittency in PDE and ODE models of axisymmetric mean-field dynamos

Eurico Covas, Reza Tavakol, Peter Ashwin +2

Employing some recent results in dynamics of systems with invariant subspaces we find evidence in both truncated and full axisymmetric mean-field dynamo models of a recently discov…

astro-ph1997

Axisymmetric mean field dynamos with dynamic and algebraic --quenchings

Eurico Covas, Reza Tavakol, Andrew Tworkowski +1

We study axisymmetric mean field spherical and spherical shell dynamo models, with both dynamic and algebraic --quenchings. Our results show that there are qualitative as well a…

astro-ph1997

Dynamos with different formulations of a dynamic alpha-effect

Eurico Covas, Andrew Tworkowski, Axel Brandenburg +1

We investigate the behaviour of dynamos with a dynamic , whose evolution is governed by the imbalance between a driving and a damping term. We focus on truncated versions o…