Magnetohydrodynamic (MHD) modelling of convective events in the solar envelope

In this thesis we have investigated effects of a toroidal type magnetic field of maximum magnitude 10 T in the lower convective region (LCR) of the Sun for a thin shell (0,703R¤ - 0,723R¤). Some early studies concerning this region are explained with respect to the dynamo mechanism, which is thought to be responsible of generating the magnetic field. Afterwards equations of magnetohdyrodynamics (MHD) relevant to this layer were solved numerically. Distributions of some physical parameters are obtained from the integration of the MHD equations in spherical coordinates and results are presented either in diagrams or in tables. It is shown that the most important feature of this type of magnetic field is to break the spherical symmetric distribution of density and change the fluid compressivity with respect to latitude. It was further shown that the MHD plasma acts as incompressive at the poles, in contrary to the perfect fluid behaviour at the equator. This type of magnetic field yields comparable magnetic flux with other research works and does not modify much the radial variations of density of the reference Standard Solar Model (SSM) model. We have also estimated the limits and applicability of the anelastic and Boussinesq approximations for the LCR layer. In our opinion, our results can be used, especially in simplifying the numerical integration of the MHD equations related to the lower convection zone in the Sun.