  Global polarization of $\Lambda$ and $\bar{\Lambda}$ is calculated based on
the axial vortical effect (AVE). Simulations are performed within the model of
the three-fluid dynamics. Equations of state with the deconfinement transition
result in a good agreement with STAR data for both $\Lambda$ and
$\bar{\Lambda}$ polarization, in particular, with the $\Lambda$-$\bar{\Lambda}$
splitting. Suppression of the gravitational-anomaly contribution required for
the data reproduction is in agreement with predictions of the QCD lattice
simulations. Predictions for the global polarization in forthcoming experiments
at lower collision energies are made. These forthcoming data will provide a
critical test for the AVE and thermodynamic mechanisms of the polarization.
