We report the first extensive experimental observation of the two-dimensional enstrophy cascade, along with the determination of the high order vorticity statistics. The energy spectra we obtain are remarkably close to the Kraichnan Batchelor expectation. The distributions of the vorticity increments, in the inertial range, deviate little from Gaussianity, and the corresponding structure function exponents are indistinguishable from zero. It is thus shown that there is no substantial small scale intermittency in the enstrophy cascade, in agreement with recent theoretical analyses.

• Received 24 March 1999

DOI:https://doi.org/10.1103/PhysRevLett.83.3418