Ostwald ripening and the kinetics of rain initiation

TL;DR

This paper applies Ostwald ripening theory to cloud droplet growth, revealing that kinetic barriers are minimal and that ripening can significantly increase droplet collision efficiency, impacting rain initiation understanding.

Contribution

It introduces the application of Lifshitz-Slezov Ostwald ripening theory to cloud physics, challenging the idea of a condensation-coalescence bottleneck in rain formation.

Findings

Kinetic barriers to rain initiation are minimal.

Ostwald ripening enhances droplet collision efficiency.

Implications for cloud physics and rain formation models.

Abstract

A central problem in cloud physics is understanding the kinetics of the growth of water droplets. It is believed that there exists a 'condensation-coalescence bottleneck' in the growth of intermediate size droplets. Here the Lifshitz-Slezov theory of Ostwald ripening is applied to the kinetics of the growth of rain drops. The analysis shows that kinetic barriers to rain initiation are not significant. It is also shown that Ostwald ripening can greatly enhance the apparent collision efficiency of droplets falling under gravity.