  We present results on the synchronization of the helicity in a liquid-metal
Rayleigh-B\'enard (RB) experiment under the influence of a tide-like
electromagnetic forcing with azimuthal wavenumber m=2. We show that for a
critical forcing strength the typical Large Scale Circulation (LSC) in the
cylindrical vessel of aspect ratio unity is entrained by the period of the
tide-like forcing, leading to synchronized helicity oscillations with opposite
signs in two half-spaces. The obtained experimental results are consistent with
and supported by numerical simulations. A similar entrainment mechanism for the
helicity in the solar tachocline may be responsible for the astonishing
synchronization of the solar dynamo by the 11.07-year triple synodic alignment
cycle of the tidally dominant planets Venus, Earth and Jupiter.
