  As a large-scale motion on the Sun, the meridional flow plays an important
role in determining magnetic structure and strength and solar cycle. However,
the meridional flow near the solar poles is still unclear. The Hinode
observations show that the magnetic flux density in polar caps decreases from
the lower latitudes to the poles. Using a surface flux transport model, we
simulate the global radial magnetic field to explore the physical process
leading to the observed polar magnetic distribution pattern. For the first
time, the high-resolution observations of the polar magnetic fields observed by
Hinode are used to directly constrain the simulation. Our simulation reproduces
the observed properties of the polar magnetic fields, suggesting the existence
of a counter-cell meridional flow in the solar polar caps with a maximum
amplitude of about 3 m s$^{-1}$.
