Vorticity field in subcritical rotating convection in a liquid metal planetary core

3D visualization of the vorticity field in a simulation of thermal convection in the liquid metal (Prandtl number Pr=0.01) of a rapidly rotating planetary core (Ekman number Ek=1e-7). The linear theory predicts a stable core (no motion). The motion are therefore called sub-critical and exist due to non-linear effects.

The equatorial plane shows the stream lines (using paraview's surface-LIC) on top of the vorticity field (blue to yellow) while the transparent meridional plane shows only the vorticity (blue to yellow) that is remarkably invariant along the rotation axis, a characteristic of the rapidly rotating convection regime.