Temperature Distribution in Coriolis-Centrifugal Convection

We present results of direct numerical simulations of Coriolis-centrifugal convection in a cylindrical container. In this system buoyancy effects not only drive convective motions in the vertical direction due to the gravitational acceleration, but also in the radial direction due to the centrifugal acceleration (Phys. Rev. Lett. 120, 2018). Here, we focus on the spatial distribution of the temperature field. Unlike in idealised Coriolis convection in which centrifugal buoyancy is neglected, the vertical temperature profiles become strongly radially dependent with increasing Froude number. In the quasi-cyclostrophic regime the temperature in the center of the fluid volume shows a strong enhancement, reaching values close to the bottom boundary temperature, whereas the temperatures at the midplane sidewall are well below the arithmetic mean. We find, further, that the axisymmetric, linear model by Hart & Ohlsen (Phys. Fluids 11.8, 1999) does not accurately predict the measured center temperatures, suggesting the need for a more sophisticated theory.