Circulation-dominated solar shell dynamo models with positive alpha-effect

We present shell dynamo models for the solar convection zone with positive alpha -effect in the northern hemisphere and a meridional circulation which is directed equatorward at the bottom and poleward at the top of the conve ction zone. Two different rotation patterns are used: a simple variation of the rotation rate with depth and the rotation law as derived by helioseism ology. Depending on the Reynolds number associated with the meridional ow, the dynamo shows a whole "zoo" of solutions. For sufficiently small values of the eddy magnetic diffusivity (10(11) cm(2)/s), field advection by the m eridional ow becomes dominant and even changes the character of the butterf ly diagram. Flow amplitudes of a few m/s are then sufficient to turn the or iginally "wrong" butterfly diagram into a "solar-type" butterfly diagram, i .e. with activity belts drifting equatorward. This effect can easily be dem onstrated with a super-rotation law (partial derivative Omega/partial deriv ativer > 0) with Omega independent of the latitude. The situation is much m ore complicated for the "real" rotation law with the observed strong negati ve shear at high latitudes. With zero meridional ow, oscillating solutions are found without any latitudinal migration of the toroidal field belts, ne ither poleward nor equatorward. Small but finite ow amplitudes cause the ma gnetic field belts to drift poleward while in case of fast ow they move equ atorward.