Lopez Brandon, Bhattacharyya Nirvan, DeVivo Jenna, Wang Mingyi, Caudillo-Plath Lucia, Surdu Mihnea, Bianchi Federico, Brasseur Zoé, Buchholz Angela, Chen Dexian, Duplissy Jonathan, He Xu-Cheng, Hofbauer Victoria, Mahfouz Naser, Makhmutov Vladimir, Marten Ruby, Mentler Bernhard, Philippov Maxim, Schervish Meredith, Wang Dongyu S, Weber Stefan K, Welti André, El Haddad Imad, Lehtipalo Katrianne, Kulmala Markku, Worsnop Douglas, Kirkby Jasper, Mauldin Roy L, Stolzenburg Dominik, Schobesberger Siegfried, Flagan Richard, Donahue Neil M
Carnegie Mellon University Department of Chemistry Pittsburgh PA USA
University of Chicago Department of the Geophysical Sciences Chicago IL USA.
Environ Sci Atmos. 2025 Jul 21. doi: 10.1039/d5ea00062a.
We present a "diagonal" Volatility Basis Set (dVBS) comparing gas-phase concentrations of oxygenated organic molecules (OOM) to their condensed-phase mass fractions. This permits closure of vapor concentrations with particle composition constrained by particle growth rates, allowing the contributions of quasi non-volatile condensation, equilibrium partitioning, and reactive uptake to be separated. The dVBS accommodates both equilibrium and dynamical (growth) conditions. Growth implies an association between gas and particle concentrations governed by a "condensation line" that is set by the particle growth rate, which fixes the total (excess) concentration of condensible vapors. The condensation line defines an infeasible region of high particle mass fraction and low gas concentration; under steady-state growth conditions, compounds cannot appear in this infeasible region without being formed by condensed-phase chemistry. We test the dVBS with observations from the CLOUD experiment at CERN using data from a FIGAERO I Chemical Ionization Mass Spectrometer measuring vapors directly and particle composition temperature programmed desorption from a filter. A dVBS analysis finds that data from an α-pinene + O run at 243 K are consistent with volatility driven condensation forming the large majority of particle mass, with no compounds clearly within the infeasible region.
我们提出了一种“对角”挥发性基集（dVBS），用于比较含氧有机分子（OOM）的气相浓度与其凝聚相质量分数。这使得在由颗粒生长速率约束颗粒组成的情况下，能够闭合气相浓度，从而可以分离准非挥发性凝聚、平衡分配和反应性吸收的贡献。dVBS 适用于平衡和动态（生长）条件。生长意味着气相和颗粒浓度之间存在一种由“凝聚线”控制的关联，该凝聚线由颗粒生长速率设定，它决定了可凝性蒸汽的总（过量）浓度。凝聚线定义了一个高颗粒质量分数和低气相浓度的不可行区域；在稳态生长条件下，化合物若不是通过凝聚相化学形成，就不会出现在这个不可行区域。我们使用来自FIGAERO I化学电离质谱仪直接测量蒸汽的数据以及来自过滤器的颗粒组成和程序升温脱附数据，通过欧洲核子研究中心（CERN）的CLOUD实验观测结果来测试dVBS。dVBS分析发现，在243K下进行的α-蒎烯 + O运行的数据与挥发性驱动的凝聚形成大部分颗粒质量一致，没有化合物明显处于不可行区域内。
