Intermittency in two-dimensional Ekman-Navier-Stokes turbulence

We study the statistics of the vorticity field in two-dimensional Navier-Stokes turbulence with linear Ekman friction. We show that the small-scale vorticity fluctuations are intermittent, as conjectured by D. Bernard, [{\it Europhys. Lett.} {\bf 50} (2000) 333] and Nam {\it et al.\/} [{\it Phys. Rev. Lett.\/} {\bf 84} (2000) 5134]. The small-scale statistics of vorticity fluctuations coincides with the one of a passive scalar with finite lifetime transported by the velocity field itself.