Surface Ekman layer
= Surface Ekman layer
{title2=$\delta_E=\sqrt{2\nu/|f|}$}
A surface <Ekman layer> is the stress-driven boundary correction below a rotating fluid’s upper boundary. For upward $z\le0$, $f>0$, constant <kinematic viscosity> and imposed complex <wind stress> $T$, its steady velocity is $W_E=T e^{\lambda z}/(\rho\nu\lambda)$, $\lambda=(1+i)/\delta_E$. The underlying <geostrophic flow> is independent of $T$ unless an additional boundary velocity condition couples them.