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 the Ion and Charged Aerosol Growth Enhancement (ION‐CAGE) code, 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 ion condensation 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. Growth rate enhancements by ion condensation are largest for aerosol sizes less than ∼25 nm and increases proportional to the ion concentration. The effect of ion condensation is expected to be most important over pristine marine areas. The model source code is made available through a public repository.

中文翻译：

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ION-CAGE代码：带电和中性气溶胶生长的数值模型

小离子的存在会影响气溶胶粒径分布的生长动力学。具体来说，经常被忽略的小离子质量会影响气溶胶的生长速度，这对于陆云的形成可能很重要。为此，我们开发了离子和带电气溶胶生长增强（ION-CAGE）代码，这是一个用于计算在存在电荷的情况下某种气溶胶的生长的数值模型，其中明确包括离子凝聚的术语。结果表明，通过这种离子缩合作用提高离子对浓度可以对气溶胶生长速率产生积极影响，这与最近的实验结果一致。然后将离子凝聚效应与带电气溶胶凝结产生的气溶胶生长进行比较，这与离子对浓度无关。约25 nm，并与离子浓度成正比增加。预计在原始海域中，离子凝结的影响最为重要。可通过公共资源库获得模型源代码。