Generation of Strong Toroidal Magnetic Field Near the Bottom of the Solar Convective Zone

Abstract

Abstract.The generation mechanism of the toroidal magnetic field by the angular velocity radial gradient acting on the relict poloidal magnetic field on the boundary between the convective and radiative zones is proposed. The magnetic induction magnitude of the toroidal field reaches about 2x10 6 " G, the limiting effect of the magnetic buoyancy being taking into account. This value conforms to the estimation of toroidal field obtained from helioseismologLcal data.Studying the helioseismological data, recently Dziembowski and Goode (1989) have shown that there is strong axisymmetric quadrupole toroidal field of magnetic induction (2il)x10 6 G centred near the base of the convective zone. The question about the origin of this magnetic field arises. In connection with fast upwelling to the surface of intensive magnetic field due to the magnetic buoyancy, it is necessary to show also how this field may reserve inside the Sun during long time. Here it is made the attempt to solve this problem with help proposed by us the mechanism of generation of the strong toroidal magnetic field in deep layers of the Sun.According this mechanism, the radial gradient of angular velocity acts on the relict poloidal magnetic field B and excites the toroidal magnetic field B. = B^il? the magnitude of which is limited by ohmic dissipation and magnetic buoyancy (Dudorov et al. 1989;Krivodubskij 1990) dB t ytot = r sin G (B^Stf*)! + V^m A B t + rot(V b xB t ). (1) 78 terms of use, available at https://www.cambridge.org/core/terms. https://doi