  We investigate the role of the correlation between a scalar quantity and the
vorticity in two-dimensional mixing at infinite P\'eclet number. We assess,
using a diffusivity independent mixing-norm, the dynamics of both
Galerkin-truncated ensembles and freely evolving two-dimensional scalar mixing.
Both statistical mechanics and numerical experiments show how the mixing-rate
is attenuated when vorticity and scalar are initially correlated. Since the
vorticity is shown to be a poorly mixing scalar, the results suggest that, in
general, mixing can be enhanced by minimizing the correlation between vorticity
and passive scalar.
