Computational Simulation of the Atmospheric Chemistry of Alkanes

根据精心设计的实验室研究确定的动力学和机理数据，将开发烷烃详细的大气氧化途径的机制。将使用现有的数值模块估计气相和冷凝相之间产品种类的分配。数值预测将与室内研究进行比较，以测试在数值模拟练习中必须估计的参数。一旦制定出令人满意的数值机制，将进行适当的简化，使其能够在三维建模框架内执行。后者将应用于许多现实世界的情况，包括南加州的南海岸空中盆地（SoCAB）、新英格兰、圣华金河谷和圣路易斯。这些模拟的一个特殊方面将是模式重现观测到的产生的二次有机气溶胶（SOA）水平的能力。在每种情况下，将生成许多模拟，以评估所使用的碳氢化合物集总方案，烷烃化学对SOA形成的影响，以及气溶胶相中存在的特定分子种类。对温度和湿度等环境变量的敏感性也将被检查。预计本研究的数值模拟产品也可用于帮助设计未来的实验室研究。这项工作将改进大气化学过程的数值表示，最终有助于更好地预测化学物质对空气质量的影响。通过更好地了解大气化学过程的机理，更可靠的控制策略是可能的。这个项目的教育方面包括本科生的研究经验和一名女性研究科学家的参与。

A mechanism for the detailed atmospheric oxidation pathways of alkanes will be developed based on kinetic and mechanistic data determined from carefully designed laboratory chamber studies. Estimates of partitioning of product species between the gas and condensed phases will be made using an existing numerical module. The numerical predictions will be compared with the chamber studies to test parameters that must necessarily be estimated in the numerical modeling exercises. Once a satisfactory numerical mechanism has been developed, appropriate simplifications will be made to allow it to be implemented within a three-dimensional modeling framework. The latter will be applied to a number of real world situations including the South Coast Air Basin (SoCAB) in southern California, New England, the San Joaquin Valley, and St. Louis. A particular aspect of these simulations will be the ability of the model to reproduce the observed levels of secondary organic aerosol (SOA) generated. In each case a number of simulations will be generated to evaluate the hydrocarbon lumping schemes utilized, the impacts of alkane chemistry on SOA formation, and the specific molecular species present in the aerosol phase. Sensitivity to environmental variables such as temperature and humidity will also be examined. It is envisioned that the numerical modeling product of this research can also be used to help design future laboratory studies. This work will lead to improved numerical representations of atmospheric chemical processes which will eventually contribute to better predictions of the impacts of chemical species on air quality. Through better mechanistic understanding of atmospheric chemical processes, more reliable control strategies are possible. Educational aspects of this project include research experiences for undergraduate students and involvement of a female research scientist.