Task A3: Coupled 3-D models of the solar radiative and convective zones (PI, Yrs 3,4,5) Scientists involved: A.S. Brun, A. Strugarek, JP. Zahn Based on our recent progresses made in modelling the solar dynamo in the bulk of the convection zone (Brun, Miesch, Toomre 2004) and the non linear dynamics of the solar radiative interior and tachocline (Brun & Zahn 2006), we will develop a coupled model of both zones to study the supposedly key role played by the solar tachocline in the dynamo process. This will allow to better understand the dynamical link and nonlinear feedback between these two zones, and to understand the solar cycle variations linked to this nonlinear coupling. We thus propose as Task A3, to develop a 3-D MHD integrated model of a portion of the radiative and convective zones, such as to be able to study in detail the nonlinear interactions between these two zones and the dynamics of the solar tachocline and radiative interior. The presence of a convection zone above the radiative interior will provide more realistic boundary conditions for the dynamical evolution of the radiative interior and its rotation profile and for the inner magnetic field, since turbulent penetrative convection, internal waves, shear and a dynamo induced field will be self consistently considered. Key questions: Which processes are at work in the tachocline? How is the tachocline established? How the inner magnetic field interacts with the dynamo generated field? Could it lead to modulation of the 11-yr cycle? What roles play the internal waves, turbulence and magnetic field in the solar stable interior? Can the tachocline easily generate strong toroidal structures that could then become unstable and reach the surface? Magnetic confinement of the solar tachocline: The oblique dipole. Strugarek , A., Brun, A.S., Zahn, J.-P. ,2011. ,Astronomische Nachrichten 332, 891. Magnetic confinement of the solar tachocline: II. Coupling to a convection zone. Strugarek, A., Brun, A.S., Zahn, J.-P. 2011. ,Astronomy and Astrophysics 532, A34. Modeling the Dynamical Coupling of Solar Convection with the Radiative Interior. Brun, A.S., Miesch, M.S., Toomre, J. 2011. ,The Astrophysical Journal 742, 79. 3D SIMULATIONS OF INTERNAL GRAVITY WAVES IN STELLAR INTERIORS L. Alvan, A. S. Brun and S. Mathis, SF2A 2012 On gravity waves in the Sun A. S. Brun, L. Alvan, A. Strugarek, S. Mathis , R. A. Garcia