A vertical soap film channel driven by gravity is used to study two-dimensional turbulence. Velocity differences on different scales and the spectrum of velocity fluctuations show behavior very different from their three-dimensional counterparts. Our findings are consistent with the theoretically predicted enstrophy cascade picture for two-dimensional turbulence. However, significant differences were observed.

• Received 17 November 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.3975