  The key elements of the Babcock-Leighton dynamos are the generation of
poloidal field through decay and dispersal of tilted bipolar active regions and
the generation of toroidal field through the observed differential rotation.
These models are traditionally known as flux transport dynamo models as the
equatorward propagations of the butterfly wings in these models are produced
due to an equatorward flow at the bottom of the convection zone. Here we
investigate the role of downward magnetic pumping near the surface using a
kinematic Babcock-Leighton model. We find that the pumping causes the poloidal
field to become predominately radial in the near-surface shear layer, which
allows the negative radial shear to effectively act on the radial field to
produce a toroidal field. We observe a clear equatorward migration of the
toroidal field at low latitudes as a consequence of the dynamo wave even when
there is no meridional flow in the deep convection zone. Both the dynamo wave
and the flux transport type solutions are thus able to reproduce some of the
observed features of the solar cycle, including the 11-year periodicity. The
main difference between the two types of solutions is the strength of the
Babcock-Leighton source required to produce the dynamo action. A second
consequence of the magnetic pumping is that it suppresses the diffusion of
fields through the surface, which helps to allow an 11-year cycle at
(moderately) larger values of magnetic diffusivity than have previously been
used.
