A flux tube solar dynamo model based on the competing role of buoyancy   and downflows
  A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by differential rotation ($\Omega$-effect) and cyclonic convection ($\alpha$-effect). As a body, the tube experiences not only a buoyant force, but also a dynamic pressure due to downflows above the tube. These two competing dynamic effects are incorporated into the $\alpha$-$\Omega$ dynamo equations through the total magnetic turbulent diffusivity, leading to a flux tube dynamo operating in the convection zone. We analyze and solve the extended dynamo equations in the linear approximation by adopting the observed solar internal rotation and assuming a downflow effect derived from numerical simulations of solar convection zone. The model reproduces: the 22-year cycle period; the extended butterfly diagram with the confinement of strong activity to low heliographic latitudes $|\Phi|\le 35^\circ$; the evidence that at low latitudes the radial field is in an approximately $\pi$ phase lag compared to the toroidal field at the same latitude; the evidence that the poleward branch is in a $\pi/2$ phase lag with respect to the equatorward branch; and the evidence that most of the magnetic flux is present in an intermittent form, concentrated into strong flux tubes. 
L. H. Li, S. Sofia (Yale), and G. Belvedere (University of Catania,   Italy)