Steady parts of rotation and magnetic field in the sun's convective envelope

Abstract

We use the full set of Chandrasekhar's (1956) MHD equations for determining the steady parts of rotation and poloidal as well as toroidal magnetic field, in the Sun's convective envelope assuming incompressibility. The boundary conditions at the surfce are taken from observations. A differential rotation is assumed to be present at the base of the convection zone. The resulting solution yields the isorotation contours similar to helioseismologically inferred rotation. However, the rotation given by the present study is much closer to the helioseismologically inferred rotation than that given by the previous study (Hiremath and Gokhale 1995b). This suggests that at the base of the convection zone, differential rotation is more likely than a rigid body rotation. The toroidal part of magnetic field structure given by the present study is similar to that given by the previous study, and has values ~ 1 G just below the surface and ~ 10 to the power 4 G near the base of the convection zone.