  Global polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons in Au+Au
collisions at collision energies $\sqrt{s_{NN}}=$ 4-40 GeV in the midrapidity
region and total polarization, i.e. averaged over all rapidities, are studied
within the scope of the thermodynamical approach. The relevant vorticity is
simulated within the model of the three-fluid dynamics (3FD). It is found that
the performed rough estimate of the global midrapidity polarization quite
satisfactorily reproduces the experimental STAR data on the polarization,
especially its collision-energy dependence. The total polarization increases
with the collision energy rise, which is in contrast to the decrease of the
midrapidity polarization. This suggests that at high collision energies the
polarization reaches high values in fragmentation regions.
