Observed and Simulated Variability of Droplet Spectral Dispersion in Convective Clouds Over the Amazon

In this study, the variability of spectral dispersion droplet size distributions (DSDs) in convective clouds is investigated. Analyses are based on aircraft measurements growing cumuli near Amazon basin, and numerical simulations an idealized ice-free cumulus. cleaner clouds, relative , defined as ratio standard deviation to mean value diameter, negatively correlated with cloud water content () adiabatic liquid (), while no strong correlation between seen polluted clouds. Bin microphysics suggest that these contrasting behaviors associated effect collision-coalescence secondary activation addition turbulent mixing parcels experienced different paths within cloud. Collision-coalescence simultaneously broadens DSDs decreases explaining inverse relationship Secondary but has little direct impact . The combination a rather modest DSD broadening due weak enhanced both diluted highly undiluted regions may contribute maintain relatively uniform These findings can be useful for parameterizing shape parameter gamma bulk cloud-resolving models. It shown emulating observed improves estimation rate compared bin simulations.