Rotating Rayleigh-Bénard convection at different latitudes

Traditionally considered rotating Rayleigh-Bénard convection can be seen as a simple model for astrophysical and geophysical flows in polar regions. Comparatively, Rayleigh-Bénard convection with spanwise rotation corresponds to flows in equatorial regions. However, it is not very clear how the flows transition in between. In this study, we consider Rayleigh-Bénard convection with rotation axis at different angles, mimicking the transition from equatorial regions to polar regions, up to Rayleigh number 10¹⁰ and Ekman number 10⁶. It is found that distinct flow patterns exist for different rotation angles, resulting in also distinct heat transfer scaling regimes. With increasing Rayleigh number, for a given rotation rate, heat is mostly contributed from the equatorial regions for low Rayleigh number, whereas, heat is contributed more from the polar regions for high Rayleigh numbers