Collaborative Research: Secondary Organic Aerosol Production in Real Atmospheric Waters

合作研究：真实大气水中二次有机气溶胶的产生

• 批准号: 1052611
• 负责人: Barbara Turpin
• 金额: $ 57.5万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1052611&HistoricalAwards=false
• 关键词: Collaborative; Research; Secondary; Organic; Aerosol

This collaborative project addresses a newly recognized (aqueous) pathway for the formation of secondary organic aerosol (SOA) in the atmosphere. The poor understanding of SOA formation is a major source of uncertainty in predictions of atmospheric aerosol concentrations and properties that affect climate, visibility and health. Current models do not capture the magnitude, distribution and dynamics of measured organic aerosol concentrations, and smog chamber experiments form SOA that is substantially less oxygenated and, therefore, less hygroscopic than aged atmospheric organic aerosol. There is growing evidence that these and other atmospheric observations can be explained, at least in part, by multiphase SOA formation involving aqueous reactions in clouds, fogs and wet aerosols. When this process is included in models, predicted SOA formed through aqueous chemistry is comparable in magnitude to that formed through the traditional pathway (e.g., gas phase reaction and partitioning to particulate organic matter) in the northeastern United States and globally. Several types of atmospheric measurements also provide evidence for this process. This project addresses the following questions: 1) Is aqueous SOA formation clearly observable in the field? 2) How does aqueous SOA formation influence the oxygen-to-carbon ratio of the organic aerosol? 3) How much of the observed aqueous SOA produced can be explained by known mechanisms? What precursors are important? 4) To what extent does SOA formation depend on light, liquid water, and organic matter? How much can be attributed to aqueous formation processes?Field measurements will be conducted during the PEGASOS campaign in the Po Valley, Italy, where conditions are ideal for SOA formation through reactions in aerosol water. In conjunction with these field studies, controlled aqueous photooxidation experiments will be conducted in the laboratory with detailed chemical analysis and chemical modeling using 1) water-soluble (filtered) mixtures of compounds scrubbed from the ambient air, 2) collected (filtered) fog water, and 3) selected compounds identified as potential aqueous precursors based on project findings. Broader Impacts: This work will further elucidate an important pathway for secondary organic aerosol formation and provide an assessment of the relative importance of this pathway in locations where conditions are favorable to SOA formation in wet aerosols and fogs. This project will provide a measurements database and a unique archive of characterized fog samples for use by other investigators. This research is designed to contribute ultimately to improved global/regional prediction of aerosol effects from precursor emissions. This project will facilitate the education of scientists. The planned K-12 outreach is designed to reach large numbers of students and to increase interest in and understanding of the process of scientific discovery by youth.

这个合作项目解决了在大气中形成二次有机气溶胶（SOA）的新认识（水）途径。对SOA形成的不了解是影响气候、能见度和健康的大气气溶胶浓度和特性预测不确定的主要来源。目前的模型没有捕捉到测量到的有机气溶胶浓度的大小、分布和动态，烟雾室实验形成的SOA的含氧程度大大降低，因此比老化的大气有机气溶胶的吸湿性更低。越来越多的证据表明，这些和其他大气观测结果可以解释，至少部分地解释，多相SOA形成涉及云、雾和湿气溶胶中的水反应。当这一过程被纳入模型时，在美国东北部和全球范围内，通过水化学形成的预测SOA的规模与通过传统途径（例如，气相反应和分配到颗粒有机物）形成的SOA相当。几种类型的大气测量也为这一过程提供了证据。该项目解决了以下问题：1)在现场是否可以清楚地观察到水性SOA的形成？2)水溶液中SOA的形成如何影响有机气溶胶的氧碳比？3)有多少观察到的含水SOA可以用已知的机制来解释？哪些前兆是重要的？4) SOA的形成在多大程度上依赖于光、液态水和有机物？有多少可以归因于水形成过程？PEGASOS项目将在意大利波谷进行现场测量，那里的条件非常适合通过气溶胶水中的反应形成SOA。结合这些实地研究，受控的水光氧化实验将在实验室进行，并进行详细的化学分析和化学建模，使用1)从环境空气中洗涤的水溶性（过滤）化合物混合物，2)收集（过滤）雾水，3)根据项目发现确定为潜在水前体的选定化合物。更广泛的影响：这项工作将进一步阐明二次有机气溶胶形成的重要途径，并提供该途径在湿气溶胶和雾中有利于SOA形成的条件下的相对重要性的评估。该项目将提供一个测量数据库和一个独特的特征雾样本档案，供其他研究者使用。这项研究的目的是最终有助于改进由前体排放产生的气溶胶效应的全球/区域预测。这个项目将促进科学家的教育。计划中的K-12外展旨在吸引大量学生，并增加青少年对科学发现过程的兴趣和理解。