Palinstrophy

Palinstrophy is the curl of the vorticity. It is defined as ${\displaystyle {\frac {1}{2}}\left(\nabla \times \omega \right),}$ where ${\displaystyle \omega }$ is the vorticity.

Palinstrophy is mainly used in turbulence study, where there is a need to quantify how vorticity is transferred from one direction to the others. It is closely related to enstrophy, the latter being more equivalent to the "power" of vorticity.