Positive vorticity advection

Positive vorticity advection refers to the process in meteorology where air with higher vorticity (a measure of the local rotation in the flow of air) is transported into a region with lower vorticity. Vorticity is associated with the circulation of air, and positive vorticity is when there is a counterclockwise rotation in the Northern Hemisphere (and clockwise in the Southern Hemisphere, due to the Coriolis effect).