Kryvodubskyj V. Dynamo parameters and reconstruction of large-scale magnetic field in the solar convection zone

The thesis deals with studies of evolution of the solar global magnetic field on the base of alpha-Omega-dynamo mechanism with taking into account the non-linear effects of turbulent plasma and newer helioseismological progress in tracing of inner rotation of the Sun. The mechanism of the turbulent reconstruction of the mean magnetic field in the solar convection zone (SCZ) as a result of the balance of magnetic buoyancy and two "negative magnetic buoyancy" phenomena is worked out. This mechanism allows to explain the observed picture of the magnetism distribution on the solar surface, in particular, the phenomenon of the magnetic field floating-up in the sunspots band. The tensor structure of the alpha-effect for solar dynamo is analysed. The contributions of the radial gradient of plasma density and the radial gradient of turbulent velocity to the alpha-effect are taken into account. The negative alpha-effect layer near the bottom of the SCZ is discovered. The radial profile of the quenching-functionwhich described the magnetic suppression of helical turbulence in the SCZ is calculated. The dynamo-cycle period is found to be about seven years that agrees by order of magnitude with the observed mean duration of the sunspot cycles. The process in the deep layers of the SCZ is shown to lead to excitation of two types of the mixed-parity dynamo modes. In the first mixed-parity regime the dipole mode is predominant (the equatorial domain) while in the second mixed-parity regime the quadruple mode is prevailed (the polar domains). The obtained configuration of the net meridional field allows to explain the magnetic "monopole" phenomenon observed during the polar magnetism reversals. The formula is derived for the calculation of the toroidal field in the interior of the Sun. It is found that the helioseismically determined radial differential rotation can excite near the solar core the strong toroidal magnetic fields (about 10 million Gauss).