On the Role of Mixing in Promoting Competition between Growing Hailstones

Abstract

Mixing processes within the hall growth zone are examined as they pertain to competition within a population of growing hailstones. Mixing is demonstrated to produce broader particle spectra than predicted by the deterministic type of model. Mixing is also noted to promote unequal competition through spectral broadening and cannot be assumed to assure equal competition in the sense implied by Sulakvelidze et al. (1974) in regard to hall suppression by beneficial competition. Treatment of particles in ensemble fashion likewise assumes equal competition. If the number of particles contained within an ensemble is very large, the resulting particle spectra may be narrower than if the particles were partitioned among several ensembles. This type of nonphysical competition is termed ?numerical competition? and may lead to serious errors in model predictions of hail growth and fallout.