Collaborative Research: Effects of Ammonia on the Chemical and Physical Properties of Atmospheric Secondary Organic Aerosol

该项目将调查氨对大气中小颗粒物的化学和物理性质的影响。 它还将研究氨对大气中棕色碳的影响。 该方法将结合联合收割机环境测量，3-D化学传输建模，并分析过去的现场活动数据。本研究的目的是：（1）研究NH_3对大气二次有机气溶胶（aqSOA）浓度和可逆/不可逆性质的影响，（2）研究NH_3对大气BrC形成的影响，（3）研究NH_3对大气BrC形成的影响，（4）研究NH_3对大气BrC形成的影响，（5）研究NH_3对大气BrC形成的影响，（6）研究NH_3对大气BrC形成的影响。（3）确定NH3对aqSOA和BrC形成影响的时空尺度。 将评估的两个过程包括由NH 4催化或直接涉及NH 4并代表高度氧化，低挥发性SOA的重要来源的水反应，以及NH 4与有机化合物的反应和可能吸收光的SOA的产生。环境测量将在美国东部的一个城市站点进行，该站点受到生物VOC排放，移动的源，以及区域农业NH3排放量。 模拟研究，使用WRF-CMAQ，将提供一个时间和空间变化的分析，在NH3对SOA和BrC的形成和对空气质量和气候的影响的影响。

This project will investigate the effects of ammonia on the chemical and physical properties of small particles in the atmosphere. It will also look at the effects of ammonia on brown carbon in the atmosphere. The approach will combine ambient measurements, 3-D chemical transport modeling, and the analysis of past field campaign data. This work will provide important insight into the sources and formation processes of secondary organic aerosol, critical for a better understanding of both air quality and climate.The objectives of the proposal are to: (1) Characterize the effects of NH3 on the concentration and reversible/irreversible nature of aqueous SOA (aqSOA); (2) Characterize the effect of NH3 on atmospheric BrC formation; and (3) Determine the spatial and temporal scales of the NH3 impacts on aqSOA and BrC formation. The two processes that will be evaluated include aqueous reactions that are either catalyzed by or directly involve NH4 and represent a significant source of highly oxidized, lower-volatility SOA, and the reaction of NH4 with organic compounds and the production of SOA that may be light-absorbing.Ambient measurements will be made at an urban site in the eastern U.S. that is heavily influenced by biogenic VOC emissions, mobile sources, and regional NH3 emissions from agriculture. Modeling studies, using WRF-CMAQ, will provide an analysis of temporal and spatial variability in the NH3 effects on SOA and BrC formation and the impacts on air quality and climate.