Observation of chaotic bursting and attractor switching in a fluid

We report observations of chaotic bursting in a fluid, a convecting layer of 3He--superfluid-4He. At an aspect ratio Γ=6.0 and Prandtl number Pr=0.3 we find intermittent bursts out of a fully developed chaotic state. Above the onset of bursting the average length of a burst-free region varies as (R-Rb)-γ with γ=4.6. The average length of a burst varies as (R-Rb)δ with δ=2.0. A particularly novel state was seen for Γ=4.25 and Pr=0.12, where there occurs a reversible switching transition involving two chaotic attractors