Variation of Magnetic Fields and Flows during the Solar Cycle

We have studied dynamo models with realistic assumptions for the induction effects and compare the resulting magnetic fields with observations. We make use of recent results of helioseismology to infer the differential rotation and adopt mixing length approach to get the form of the ct-effect, which is in general anisotropic. Dynamo models are computed numerically using an eigenva.lue method. Finally, we discuss the resulting Lorentz force, which is relevant for explaining observed flows such as the torsional waves, as a back reaction of the dynamo magnetic fields. Comparison is made in particular with Mt.Wilson/Kitt Peak magnetograms and synoptic charts showing the magnetic flux, torsional oscillation pattern, and the distribution of ephemeral regions, coronal activity, and polar faculae.