= Two-layer Sverdrup interior
{title2=$V=W/\beta$}
For a uniform normalized upper-layer <wind stress curl> $W$ and no lower-layer forcing, a uniform local <Sverdrup balance> is
$$
\bar\psi_1=Vx,\quad\bar\psi_2=0,\quad V=W/\beta.
$$
The upper layer flows meridionally and the lower layer rests. Although the relative <vorticity> vanishes, the <potential vorticity> has the zonal gradients $\bar q_{1,x}=-FV$, $\bar q_{2,x}=FV$. These are essential for the perturbation stability and do not vanish merely because the background velocity is uniform.
Back to article page
