Abstract Cooking organic aerosol (COA) is potentially a significant fraction of organic particulate matter in urban areas. COA chemical aging experiments, using aerosol produced by grilling hamburgers, took place in a smog chamber in the presence of UV light or excess ozone. The water solubility distributions, cloud condensation nuclei (CCN) activity, and corresponding hygroscopicity of fresh and aged COA were measured. The average mobility equivalent activation diameter of the fresh particles at 0.4% supersaturation ranged from 87 to 126 nm and decreased for aged particles, ranging from 65 to 88 nm. Most of the fresh COA had water solubility less than 0.1 g L−1, even though the corresponding particles were quite CCN active. After aging, the COA fraction with water solubility greater than 0.1 g L−1 increased more than 2 times. Using the extended Kohler theory for multiple partially soluble components in order to predict the measured activation diameters, the COA solubility distribution alone could not explain the CCN activity. Surface tensions less than 30 dyn cm−1 were required to explain the measured activation diameters. In addition, COA particles appear to not be spherical, which can introduce uncertainties into the corresponding calculations.

中文翻译：

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新鲜和老化蒸煮有机气溶胶的云凝结核活性和吸湿性

摘要 烹饪有机气溶胶 (COA) 可能是城市地区有机颗粒物的重要组成部分。COA 化学老化实验使用由烧烤汉堡包产生的气溶胶，在有紫外线或过量臭氧的烟雾室中进行。测量了新鲜和老化 COA 的水溶性分布、云凝结核 (CCN) 活性和相应的吸湿性。新鲜颗粒在 0.4% 过饱和度下的平均流动等效活化直径范围为 87 至 126 nm，而老化颗粒的平均流动等效活化直径范围为 65 至 88 nm。大多数新鲜 COA 的水溶性小于 0.1 g L-1，即使相应的颗粒具有相当的 CCN 活性。老化后，水溶性大于 0.1 g L−1 的 COA 分数增加了 2 倍以上。使用多个部分可溶组分的扩展科勒理论来预测测量的活化直径，单独的 COA 溶解度分布不能解释 CCN 活性。需要小于 30 dyn cm-1 的表面张力来解释测量的活化直径。此外，COA 颗粒似乎不是球形的，这会给相应的计算带来不确定性。