www.elsevier.com/locate/physa Pair dispersion in turbulence

We study the statistics of pair dispersion in two-dimensional turbulence. Direct numerical simulations show that the probability distribution function (pdf) of pair separations is in agree-ment with the Richardson prediction. The pdf of doubling times follows dimensional scaling and shows a long tail which is the signature of close approaches between particles initially seeded with a large separation. This phenomenon is related to the formation of fronts in passive scala