Atmospheric Nucleation: Quantum Calculations, Kinetic Modeling, and Regional Scale Investigations

该项目旨在通过以下途径提高对大气成核的认识：（1）分子团簇热力学的量子力学研究;（2）改进现有理论和发展新的成核模型;（3）将动力学模拟结果与大气成核事件的新数据进行比较;（4）对羽流中粒子形成的综合研究;（5）对大气成核过程的研究。及（5）发展成核率查询表，在现有的三维空气质素模式中加入计算效率高的成核模式，以及研究区域尺度的成核过程。 一种新的方法，集成了量子力学研究集群热力学与动力学成核建模。 该模型将用于改进和扩展现有的二元均相成核理论、三元均相成核理论和离子介导成核理论，并发展三元离子介导成核理论和有机物增强成核理论。 还将研究二元和三元气体混合物中的离子符号偏好。 最近的测量预成核集群，集群离子的迁移率谱，和新的成核纳米粒子的带电分数将在模型的上下文中进行分析。教育和培训的机会将提供给研究生和博士后学生。 将向其他调查人员提供在本项目下编制的成核率查询表。 这项工作的更广泛的科学影响包括有助于量化气溶胶间接辐射强迫对地球气候的影响。

This project seeks to improve knowledge of atmospheric nucleation through: (1) quantum mechanical studies of the thermodynamics of molecular clusters; (2) improvement of existing theories and development of new nucleation models; (3) comparison of kinetic modeling results with new data on atmospheric nucleation events; (4) a comprehensive study of particle formation in plumes; and (5) development of nucleation rate look-up tables, incorporation of computationally efficient nucleation modules in existing 3-dimensional air quality models, and an investigation of nucleation processes at regional scales. A novel approach that integrates a quantum mechanics study of cluster thermodynamics with kinetic nucleation modeling will be employed. This model will be used to improve and extend current binary homogeneous, ternary homogeneous, and ion-mediated nucleation theories, and to develop new theories of ternary ion-mediated nucleation and the enhancement of nucleation by organic compounds. The ion sign preference in binary and ternary gaseous mixtures will also be investigated. Recent measurements of pre-nucleation clusters, mobility spectra of cluster ions, and the charged fraction of freshly nucleated nanoparticles will be analyzed in the context of the model.Education and training opportunities will be provided for graduate and postdoctoral students. Nucleation rate look-up tables to be developed under this project will be made available to other investigators. Broader scientific impacts of this work include contributions to quantification of the effects of aerosol indirect radiative forcing on Earth's climate.