Potential-vorticity gradient
= Potential-vorticity gradient
{title2=$\nabla\bar q$}
The spatial <gradient> of <potential vorticity> controls the anomaly created when a parcel is displaced. The linear <potential-vorticity equation> contains $\mathbf u'\cdot\nabla\bar q$. A gradient of the <Coriolis parameter> contributes <planetary vorticity>, but gradients of relative <vorticity> and layer stretching can be equally important.