Modeling Aqueous Secondary Organic Aerosol Formation

该项目的目标是更好地了解云滴和湿大气颗粒中可能导致大气中次级小颗粒形成的化学过程。一个模型将应用于2013年南方氧化剂和气溶胶研究期间实地收集的数据，以评估自然排放到大气中的命运。这项研究工作将增进对通过在云滴和气溶胶液态水中处理而影响小颗粒形成的因素的理解，从而导致改进的大气化学、空气质量和气候模型。最新的模拟方法将被用于评估含水二次有机气溶胶(AQSOA)的形成及其对气溶胶质量、组成和光学性质的影响。水处理允许从高挥发性物种中形成SOA，包括异戊二烯的氧化产物，如乙二醛和异戊二烯环氧二醇(IEPOX)。光化学盒模型--用于机理分析的气体-气溶胶模型(GAMMA)及其简化版本(SIMPLE GAMMA)将用于使用有限的气相示踪剂输入对实地数据进行分析。SimpleGAMMA计算效率高，适合与更大尺度的大气化学模式耦合。SimpleGAMMA水气溶胶SOA形成方案将与其他SOA形成方案进行详细的比较，例如来自社区多尺度空气质量(CMAQ)模式的IEPOX SOA方案。PI还将在几个3D区域和全球模型中引入或更新AQSOA形成方案，包括GEOS-Chem、GISS ModelIE2地球系统模型和WRF-Chem。这项工作将改善大气化学模式的预报能力。

The objective of this project is to develop a better understanding of chemical processes occurring in cloud droplets and wet atmospheric particles that can lead to the formation of secondary small particles in the atmosphere. A model will be applied to data collected in the field in 2013 during the Southern Oxidant and Aerosol Study to evaluate the fate of natural emissions to the atmosphere. This research effort will improve the understanding of factors that influence the formation of small particles through processing in cloud droplets and aerosol liquid water, hence leading to improved models of atmospheric chemistry, air quality and climate.State-of-the-art modeling approaches will be used to evaluate the formation of aqueous Secondary Organic Aerosol (aqSOA) and their impacts on aerosol mass, composition, and optical properties. Aqueous processing allows SOA formation from highly volatile species, including oxidation products of isoprene, such as glyoxal and isoprene epoxydiols (IEPOX). A photochemical box model, Gas-Aerosol Model for Mechanism Analysis (GAMMA) and its simplified version (simpleGAMMA), will be applied to analyses of field data using limited gas-phase tracer inputs. SimpleGAMMA was developed to be computationally efficient and suitable for coupling with larger-scale atmospheric chemistry models.A detailed intercomparison will be conducted of the SimpleGAMMA aqueous aerosol SOA formation scheme and other SOA formation schemes, such as the IEPOX SOA scheme from the Community Multi-scale Air Quality (CMAQ) model. The PI will also introduce or update aqSOA formation schemes in several 3D regional and global models including GEOS-Chem, GISS ModelIE2 Earth System Model, and WRF-Chem. This work will result in improved prognostic capabilities for atmospheric chemistry models.