The Ion and Charged Aerosol Growth Enhancement (ION-CAGE) code: A numerical model for the growth of charged and neutral aerosols

TL;DR

This paper introduces the ION-CAGE numerical model that simulates charged and neutral aerosol growth, explicitly including ion-condensation effects, which are significant for understanding cloud formation processes.

Contribution

The paper presents a new numerical model that explicitly incorporates ion-condensation effects into aerosol growth simulations, advancing understanding of charged aerosol dynamics.

Findings

Ion-condensation increases aerosol growth rate with higher ion-pair concentrations.

Charged aerosol coagulation growth is unaffected by ion-pair concentration.

Model source code is publicly available for further research.

Abstract

The presence of small ions influences the growth dynamics of a size distribution of aerosols. Specifically the often neglected mass of small ions influences the aerosol growth rate, which may be important for terrestrial cloud formation. To this end, we develop a numerical model to calculate the growth of a species of aerosols in the presence of charge, which explicitly includes terms for ion-condensation. It is shown that a positive contribution to aerosol growth rate is obtained by increasing the ion-pair concentration through this effect, consistent with recent experimental findings. The ion-condensation effect is then compared to aerosol growth from charged aerosol coagulation, which is seen to be independent of ion-pair concentration. The model source code is made available through a public repository.