Kang Hyun Gu, Kim Youngjin, Collier Sonya, Zhang Qi, Kim Hwajin
Environment, Health, and Welfare Research Center, Korea Institute of Science and Technology, Seoul, South Korea; Now at the Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.
Environment, Health, and Welfare Research Center, Korea Institute of Science and Technology, Seoul, South Korea.
Environ Pollut. 2022 Jul 1;304:119203. doi: 10.1016/j.envpol.2022.119203. Epub 2022 Mar 23.
The volatilities of ambient organic aerosol (OA) components are important to forecasting OA formation with models. However, providing the OA volatility distribution inputs for models is challenging, and models often rely on measurements from chamber experiments. We measured the volatility of submicron ambient OA in Seoul during May/June of 2019 by connecting a thermodenuder to an Aerodyne Time-of-Flight Aerosol Mass Spectrometer (AMS). We calculated a volatility basis set (VBS) of the organic aerosol with a thermodenuder mass transfer model and data from the thermodenuder set to various temperatures (30-200 °C). We found a large discrepancy between the measured ambient VBS and a reference VBS used in air quality models, with the ambient organics being less volatile. The results suggest that a modeling study that tries to account for this discrepancy may be needed to identify the impact it has on modeling outcomes. Chamber experiments aiming to determine VBSs for specific chemical systems should address limitations caused by wall losses and incomplete modeling parameters.
大气有机气溶胶（OA）成分的挥发性对于用模型预测OA形成至关重要。然而，为模型提供OA挥发性分布输入具有挑战性，并且模型通常依赖于腔室实验的测量结果。我们在2019年5月/6月期间，通过将热脱附器连接到 Aerodyne飞行时间气溶胶质谱仪（AMS）上，测量了首尔亚微米级大气OA的挥发性。我们使用热脱附器传质模型以及热脱附器在不同温度（30 - 200°C）下的数据，计算了有机气溶胶的挥发性基准集（VBS）。我们发现测量的大气VBS与空气质量模型中使用的参考VBS之间存在很大差异，大气有机物的挥发性较低。结果表明，可能需要进行一项建模研究来考虑这种差异，以确定其对建模结果的影响。旨在确定特定化学系统VBS的腔室实验应解决壁面损失和建模参数不完整所造成的局限性。
