Lagrangian supersaturation fluctuations at the cloud edge

TL;DR

This paper develops a statistical model to understand supersaturation fluctuations at cloud edges caused by turbulence-induced droplet evaporation, validated by numerical simulations.

Contribution

It introduces a novel statistical model capturing local droplet-supersaturation correlations, advancing understanding of cloud edge dynamics.

Findings

Model accurately predicts supersaturation fluctuations.

Results align quantitatively with direct numerical simulations.

Explains key mechanisms of droplet evaporation at cloud edges.

Abstract

Evaporation of cloud droplets accelerates when turbulence mixes dry air into the cloud, affecting droplet-size distributions in atmospheric clouds, combustion sprays, and jets of exhaled droplets. The challenge is to model local correlations between droplet numbers, sizes, and supersaturation, which determine supersaturation fluctuations along droplet paths (Lagrangian fluctuations). We derived a statistical model that accounts for these correlations. Its predictions are in quantitative agreement with results of direct numerical simulations, and it explains the key mechanisms at play.