Enhanced azimuthal rotation of the large-scale flow through stochastic cessations in turbulent rotating convection with large Rossby numbers

Abstract

We present measurements of the azimuthal orientation θ(t) and thermal amplitude δ(t) of the large-scale circulation (LSC) of turbulent rotating convection within an unprecedented large Rossby number range 1<Ro<314. Results of θ(t) reveal persistent rotation of the LSC flow in the retrograde direction over the entire Ro range. The rotation speed ratio remains a constant of 0.13($\pm$0.01) for 10<Ro<70, but starts to increase with increasing Ro when Ro>70. We identify the mechanism through which the mean retrograde rotation speed can be enhanced by stochastic cessations in the presence of weak Coriolis force, and show that a low-dimensional, stochastic model provides predictions of the observed large-scale flow dynamics and interprets its retrograde rotation.

arXiv commentThe manuscript contains 5 pages and 5 figures

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Cited by in corpus (4)

• Heat transport scaling and transition in geostrophic rotating convection with varying aspect ratio
• Fine vortex structure and flow transition to the geostrophic regime in rotating Rayleigh-Bénard convection
• Low-dimensional model of the large-scale circulation of turbulent Rayleigh-B{é}nard convection in a cubic container
• Effects of tilt on the orientation dynamics of the large-scale circulation in turbulent Rayleigh-B{é}nard convection