Abstract
Recent observation have shown that the axisymmetric flow in Sun`s surface to the base of the convection zone. The subsurface meridional flow plays an important role in the dynamics of the sunspot cycle. It is of importance to learn how the subsurface meridional flow varies with the eleven-year sunspot cycle. Here we report the study of subsurface meridional flow as a function of latitude and depth down to a depth of 13% of the solar radius in the period from 1994 to 2000 covering the solar minimum in 1996 and maximum in 2000. We find that the velocity of meridional flow increased as sunspot number decrease from 1994 to 1997.As the sunspot number increased from 1997 to 2000,a new component of meridional flow,centered at about 20° latitude,was created in each hemisphere. It moves away from the center. This additional component changes the observed meridional flow from poleward to equatoward near the equator in both hemispheres. The velocity of the additional meridional flow increase with depth at least down to a depth of 70000 km,~10% of the solar radius. The variation of the subsurface meridional flow plays an important dynamical role in the sunspot cycle. It can be used as a tool to probe the magnetic fields deep in the convection zone.