  Floating particles that are initially distributed uniformly on the surface of
a turbulent fluid, subsequently coagulate, until finally a steady state is
reached. This being so, they manifestly form a compressible system. In this
experiment, the information dimension D_1, and the Lyapunov exponents of the
coagulated floaters, are measured. The trajectories and the velocity fields of
the particles are captured in a sequence of rapidly acquired images. Then the
velocity sequence is randomly shuffled in time to generate new trajectories.
This analysis mimics the Kraichnan ensemble and yields properties of a velocity
correlation function that is delta-correlated in time (but not in space). The
measurements are compared with theoretical expectations and with simulations of
Boffetta et al., that closely mimic the laboratory experiment reported here.
