Vorticity advection

From Glossary of Meteorology

vorticity advection

Advection of vorticity by the total wind:
where v is the total wind vector, p is the del operator on an isobaric surface, ζ is the relative vorticity, and f is the planetary vorticity (the Coriolis parameter).

Vorticity advection is one parameter used in the prediction of vertical motion in the atmosphere: Positive vorticity advection corresponds to rising motion, and negative vorticity advection corresponds to sinking motion (
see omega equation). Synoptically, the 500-mb level is used to evaluate vorticity advection since it is close to the level of nondivergence in the atmosphere where vorticity is approximately conserved.