2008/06/16 by P. Garaud, Pascale Garaud, Jean-Didier D. Garaud +1 · 2 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Convection #Convection zone #Differential rotation #Helioseismology #Radiation zone #Radiative transfer #Solar and Space Plasma Dynamics #Solar rotation #Stellar, planetary, and galactic studies #Tachocline #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13930.x
21 pages, 15 figures, submitted to MNRAS
arxiv created 2008/06/16 · openalex publication_date 2008/11/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a detailed numerical study of the Gough & McIntyre model for the solar tachocline. This model explains the uniformity of the rotation profile observed in the bulk of the radiative zone by the presence of a large-scale primordial magnetic field, confined below the tachocline by flows originating from within the convection zone. We attribute the failure of previous numerical attempts at reproducing even qualitatively Gough & McIntyre's idea to the use of inappropriate boundary conditions at the radiative–convective interface. We emphasize the key role of flows downwelling from the convection zone in confining the assumed internal field. We carefully select the range of parameters used in the simulations to guarantee a faithful representation of the hierarchy of expected length-scales. We then present, for the first time, a fully non-linear and self-consistent numerical solution of the Gough & McIntyre model which qualitatively satisfies the following set of observational constraints: (i) the quenching of the large-scale differential rotation below the tachocline – including in the polar regions – as seen by helioseismology (ii) the confinement of the large-scale meridional flows to the uppermost layers of the radiative zone as required by observed light element abundances and suggested by helioseismic sound-speed data.