Pathak Ravikant, Donahue Neil M, Pandis Spyros N
Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA, USA.
Environ Sci Technol. 2008 Jul 15;42(14):5081-6. doi: 10.1021/es070721z.
The SOA formation from beta-pinene ozonolysis at modest precursor concentrations (2-40 ppb) was investigated in the temperature range of 0-40 degrees C. The presence of inert seeds and high ozone concentrations is necessary to minimize losses of semivolatile vapors to the walls of the smog chamber. beta-pinene secondary organic aerosol production increases significantly with decreasing temperature. An increase by a factor of 2-3, depending on the reacted beta-pinene concentration, was observed as the temperature decreased from 40 to 0 degrees C. This increase appearsto be due mainly to the shifting of partitioning of the semivolatile SOA componentstoward the particulate phase and not to a change of the beta-pinene product distribution with temperature. The measurements are used to develop a new temperature-dependent parametrization for the four-component basis-set. The parametrization predicts much higher SOA production for beta-pinene ozonolysis for typical atmospheric conditions than the values that have been suggested by previous studies.
在0至40摄氏度的温度范围内，研究了中等前驱体浓度（2 - 40 ppb）下β-蒎烯臭氧分解形成二次有机气溶胶（SOA）的情况。为了尽量减少半挥发性蒸汽在烟雾箱壁上的损失，需要存在惰性种子和高浓度臭氧。β-蒎烯二次有机气溶胶的生成量随温度降低而显著增加。当温度从40摄氏度降至0摄氏度时，观察到生成量增加了2至3倍，这取决于反应的β-蒎烯浓度。这种增加似乎主要是由于半挥发性SOA组分的分配向颗粒相转移，而不是β-蒎烯产物分布随温度的变化。这些测量结果被用于开发一种新的基于四组分基础集的温度相关参数化方法。该参数化方法预测，在典型大气条件下，β-蒎烯臭氧分解产生的SOA量比先前研究提出的值要高得多。
