Science / Weather / 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's surface. If it does not spin, it is said to have zero vorticity. In the Northern Hemisphere, the vorticity is positive when the parcel has a counterclockwise, or cyclonic, rotation. It is negative when the parcel has clockwise, or anticyclonic, rotation.
Science / Weather / Negative Vorticity Advection: The advection of lower values of vorticity into an area. MORE
Science / Weather / Vorticity Maximum: A center of vorticity, or the maximum of the vorticity field of a fluid. MORE