Quenching of the alpha effect in the Sun -- what observations are   telling us
  The Babcock-Leighton type of dynamo has received recent support in terms of the discovery in the observational records of systematic cycle-to-cycle variations in the tilt angle of sunspot groups. It has been proposed that these variations might be the consequence of the observed inflow into the active region belt. Furthermore simulations have shown that such inflows restrict the creation of net poloidal flux, in effect acting to quench the alpha effect associated with the Coriolis force acting on rising flux tubes. In this paper we expand on these ideas. 
R. H. Cameron
astro-ph.SR