Planetary core-style rotating convective flows in paraboloidal laboratory experiments

<p><span>Turbulent convection in a planet's outer core is simulated here using a thermally-driven free surface paraboloidal laboratory annulus. We show that the rapidly rotating convection dynamics in free-surface paraboloidal annuli are similar to those in planetary spherical shell geometries. Three experimental cases are carried out, respectively, at 35 revolutions per minute (rpm), 50 rpm and 60 rpm.Thermal Rossby waves are detected in full</span><span> disk thermographic images of the fluid's free surface.</span> <span>Ultrasonic flow velocity measurements reveal the presence of multiple azimuthal (zonal) jets, with successively more jets</span><span> forming in higher rotation rate cases.</span> <span>The jets' cylindrical radial extent is well ap</span><span>proximated by the Rhines scale.</span> <span>Over time, the zonal jets migrate to larger radial po</span><span>sition with migration rates in good agreement with prior theoretical estimates.</span> <span>Our re</span><span>sults suggest that planetary core rotating convection will be comprised of flow structures found</span><span> in other turbulent geophysical fluid dynamical systems:</span> <span>convective turbulence dom</span><span>inates the small-scale flow field, and also act to flux energy into larger-scale, slowly evolv</span><span>ing zonal flow structures.</span> <span>How the ambient magnetic fields in planetary core settings af</span><span>fect such turbulent flows remains an open question.</span></p>