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arXiv · 2207.09981

Synchronizing the helicity of Rayleigh-B\'enard convection by a tide-like electromagnetic forcing

Peter Jüstel·Sebastian Röhrborn·Sven Eckert·Vladimir Galindo·Thomas Gundrum·Rodion Stepanov·Frank Stefani
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Abstract

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.

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Peter Jüstel, Sebastian Röhrborn, Sven Eckert, Vladimir Galindo, Thomas Gundrum, Rodion Stepanov, Frank Stefani. 2022-07-20. Synchronizing the helicity of Rayleigh-B\'enard convection by a tide-like electromagnetic forcing. https://doi.org/10.1063/5.0114035

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