Speaker
Prof.
Alfio Bonanno
Description
Most probably the sunspot cycle period is ruled by a
meridional flow located near the base of the convection zone
(Hathaway et al. 2003). On the other hand, if the eddy
diffusivity is low enough, dramatic modification of the
standard α2Ω-dynamo by the meridional flow are expected. In
this paper we shall discuss the dependence of periods,
dynamo numbers and the sign of the current helicity as a
function of the magnetic Reynolds number for a double cell
meridional circulation and for a positive α-effect at the
base of the convection zone. The dynamo action occurs at
lower latitudes and its location is at the interface between
equatorward and poleward motions near the base of the
convection zone. In spite of the complexity of the flow
pattern, our simulations show that the resulting dynamo
action reproduces several observed features of the solar cycle.
