Velocimetry in rapidly rotating convection: Spatial correlations, flow structures and length scales ^(a)

Rotating Rayleigh--B\'enard convection is an oft-employed model system to evaluate the interplay of buoyant forcing and Coriolis forces due rotation, eminently relevant interaction dynamical effects found in many geophysical astrophysical flows. These flows display extreme values governing parameters: large Rayleigh numbers $Ra$, quantifying strength thermal forcing, small Ekman $E$, a parameter inversely proportional rotation rate. This leads dominant geostrophic balance flow between pressure gradient force. The so-called regime rotating difficult study with laboratory experiments numerical simulations given requirements attain simultaneously $Ra$ $E$. Here, we use measurements using stereoscopic particle image velocimetry large-scale apparatus horizontal plane at mid-height rich phenomenology convection. We quantify length scales spatial correlations vertical velocity vorticity, reproducing features convective Taylor columns plumes states both part regime. Additionally, find this organisation into quadrupolar vortex higher starting from state.