OBSERVATION OF ANOMALOUS DIFFUSION AND LEVY FLIGHTS IN A 2-DIMENSIONAL ROTATING FLOW

Chaotic transport in a laminar fluid flow in a rotating annulus is stu died experimentally by tracking large numbers of tracer particles for long times Sticking and unsticking of particles to remnants of invaria nt surfaces (Cantori) around vortices results in superdiffusion: The v ariance of the displacement grows with time as t(gamma) with gamma = 1 .65+/-0.15. Sticking and flight time probability distribution function s exhibit power-law decays with exponents 1.6+/-0.3 and 2.3+/-0.2, res pectively. The exponents are consistent with theoretical predictions r elating Levy flights and anomalous diffusion.