Supersaturation in the Wake of a Precipitating Hydrometeor and its Impact on Aerosol Activation

TL;DR

This study uses numerical simulations to show that supersaturation in the wake of precipitating hydrometeors can activate aerosols, significantly influencing cloud formation and secondary aerosol production.

Contribution

It provides the first detailed numerical analysis of wake-induced supersaturation and its role in aerosol activation, expanding understanding of cloud microphysics.

Findings

A significant fraction of aerosols are activated in the wake's supersaturated environment.

Wake-induced activation can rival other secondary aerosol production processes.

Aerosols entrained in wake vortices remain in supersaturation long enough for activation.

Abstract

The secondary activation of aerosols impacts the life cycle of a cloud. A detailed understanding is necessary for reliable climate prediction. Recent laboratory experiments demonstrate that aerosols can be activated in the wake of precipitating hydrometeors. However, many quantitative aspects of this wake-induced activation remain unclear. Here, we report a detailed numerical investigation of the activation potential of wake-induced supersaturation. By Lagrangian tracking of aerosols we show that a significant fraction of aerosols are activated in the supersaturated wake. These 'lucky aerosols' are entrained in the wake's vortices and reside in the supersaturated environment sufficiently long to be activated. Our analyses show that wake-induced activation can contribute at a level similar to other well known secondary production processes.