Abstract. W e analyze the behavior of the correlation for two nearby trajectories of motion in a random incompressible o w with nonzero mean and small uctuations. W e show that the Fourier transform of the Richardson function of a passive scalar advected by the ow satis es, under certain conditions, a radiative transport equation. We also study the stretching of curves advected by the ow and show that their length grows algebraically in time, and not exponentially as it does for time dependent, zero mean random ows.
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