Środowiskowe Seminarium Fizyki Atmosfery

Collision-coalescence of cloud droplets driven by differential sedimentation is an important mechanism for formation of rain. Theoretical parametrizations (to be used in stochastic simulations of collision-coalescence processes) requires a statistical characterization of the spatial distribution of droplets sedimenting in the complex flow environment of a cloud. This talk is concerned with the spatial distribution statistics of hard spheres sedimenting in low-Reynolds number flow. In this regime small-scale turbulence is absent. Careful numerical simulations and theoretical considerations show that the widely used assumption of random (uncorrelated) distribution of spheres in space is unphysical.