Look up: vorticity

1. vorticity
   generally,rotational motion in a fluid,defined at any point in a fluid as twice the mean angular velocity of a small element of fluid surrounding the point Category: Transport • (a) in a general sense, rotational circulation of air about an axis, the orientation of which is arbitrary. Category: The cosmos
   Found on http://www.mijnwoordenboek.nl/definition
   
   
2. Vorticity
   ==Fluid dynamics== In fluid dynamics, vorticity is the curl of the fluid velocity. It can also be considered as the circulation per unit area at a point in a fluid flow field. It is a vector quantity, whose direction is along the axis of the fluid`s rotation. For a two-dimensional flow, the vortici...
   Found on http://en.wikipedia.org/wiki/Vorticity
   
   
3. VORTICITY
   The measurement of the rotation of a small air parcel. It has vorticity when the parcel spins as it moves along its path. Although the axis of the rotation can extend in any direction, meteorologists are primarily concerned with the rotational motion about an axis that is perpendicular to the earth'...
   Found on http://www.weather.com/glossary/v.html