Rapidly rotating radiatively driven convection: experimental and numerical validation of the ‘geostrophic turbulence’ scaling predictions

We experimentally and numerically characterize rapidly rotating radiatively driven thermal convection, beyond the sole heat transport measurements reported by Bouillaut et al. ( Proc. Natl Acad. Sci. , vol. 118, 2021, e2105015118). Based on a suite of direct numerical simulations (DNS) and additional processing of the experimental data collected by Bouillaut et al. ( Proc. Natl Acad. Sci. , vol. 118, 2021, e2105015118), we report the simultaneous validation of the scaling predictions of the ‘geostrophic turbulence’ regime – the diffusivity-free or ‘ultimate’ regime of rapidly rotating convection – for the heat transport and the temperature fluctuations. Following such cross-validation between DNS and laboratory experiments, we further process the numerical data to validate the ‘geostrophic turbulence’ scaling predictions for the flow velocity and horizontal scale. Radiatively driven convection thus appears as a versatile set-up for the laboratory observation of the diffusivity-free regimes of various convective flows of geophysical and/or astrophysical interest.