The Fourth-Order Correlation Function of a Randomly Advected Passive Scalar

Abstract

Advection of a passive scalar $\theta$ in $d=2$ by a large-scale velocity field rapidly changing in time is considered. The Gaussian feature of the passive scalar statistics in the convective interval was discovered in \cite{95CFKLa}. Here we examine deviations from the Gaussianity: we obtain analytically the simultaneous fourth-order correlation function of $\theta$. Explicit expressions for fourth-order objects, like $⟨({\theta }_1-{\theta }_2{)}^4⟩$ are derived.

4 pages, RevTex 3.0, To appear in JETP Lett. {\bf 61}, (1995)

Cited by in corpus (4)

• Large-scale properties of passive scalar advection
• Passive advection in nonlinear medium
• Strong effect of weak diffusion on scalar turbulence at large scales
• Passive scalar mixing and decay at finite correlation times in the Batchelor regime