(1) interaction of molecular diffusion with simple
unidirectional shear flows (bounded and unbounded domains).
(2) Limitation of the effective diffusion approximation to
long times and small domains, and low moments of the tracer
(3) Perhaps a geophysical example: shear diffusion in the
internal gravity wave field. The vertical tracer cascade of
Haynes & Anglade.
(4) Some examples of pre-asymptotic anomalous shear
diffusion e.g.,〈x2〉 ∼ t ln t due to the no-slip
condition, and 〈x2〉 ∼ t 3/2 in the example of de
Marsily & Matheron.