Particle Growth Mechanisms During Ambient New Particle Formation

环境新粒子形成过程中的粒子生长机制

• 批准号: 1205304
• 负责人: Murray Johnston
• 金额: $ 19.07万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1205304&HistoricalAwards=false
• 关键词: Particle; Growth; Mechanisms; During; Ambient

New particle formation (NPF) in the atmosphere has been observed all over the globe, from remote boreal forests in Finland to polluted megacities such as Mexico City. Although it is pervasive, NPF is not that well understood owing in large part to its chemical complexity, which encompasses everything from gas phase species, to molecular clusters, to "bulk" nanoparticulate matter. This project will employ a unique Nano Aerosol Mass Spectrometer (NAMS) to measure the elemental composition of individual size-selected particles (10-30 nm size range) during two multi-investigator field campaigns, one in Pittsburgh, Pennsylvania in 2012 and another at the Department of Energy's Atmospheric Radiation Measurement (ARM) program Southern Great Plains site in northern Oklahoma in 2013. The results will allow particle growth by sulfate vs. organics and other inorganic species during NPF to be quantified. Measured growth rates will be compared to predicted growth rates based on gas phase concentrations and used to assist development of models for particle growth. The NAMS will also provide key information to help determine how much cationic nitrogen exists in nanoparticles beyond that needed to neutralize inorganic acids. The results will give a more quantitative measure of the impact of amines on particle growth. In addition, the NAMS will quantify how changes in ambient particle composition correlate with changes in hygroscopicity/volatility. The results will provide an independent assessment of how well indirect measurements of chemical composition based on laboratory studies of hygroscopicity/volatility give an indication of the true ambient composition.Scientific impacts will derive from better understanding of NPF and their linakge to cloud condensation nucleus (CCN) concentrations which, in turn, have important impacts on precipitation patterns and Earth's energy balance. Educational broader impacts will include promotion of teaching and learning through the support of two graduate students. Outreach efforts will include engaging the broader community via an annual "Coast Day" event during which the principal investigator will present some aspects of the work.

从芬兰偏远的北方森林到墨西哥城等受污染的大城市，全球各地都观察到了大气中新颗粒的形成（NPF）。尽管 NPF 很普遍，但人们对它的了解还不是很充分，这在很大程度上是因为它的化学复杂性，它涵盖了从气相物质到分子簇，再到“块状”纳米颗粒物质的所有内容。该项目将采用独特的纳米气溶胶质谱仪 (NAMS)，在两次多研究人员现场活动中测量单个尺寸选定颗粒（10-30 nm 尺寸范围）的元素组成，一次是 2012 年在宾夕法尼亚州匹兹堡，另一次是 2013 年在俄克拉荷马州北部的能源部大气辐射测量 (ARM) 计划南大平原站点。结果将允许颗粒生长 NPF 期间的硫酸盐与有机物和其他无机物进行量化。将测量的生长速率与基于气相浓度的预测生长速率进行比较，并用于协助开发颗粒生长模型。 NAMS 还将提供关键信息，帮助确定纳米颗粒中存在多少超出中和无机酸所需的阳离子氮。结果将更定量地测量胺对颗粒生长的影响。此外，NAMS 将量化环境颗粒成分的变化如何与吸湿性/挥发性的变化相关。结果将为基于吸湿性/挥发性实验室研究的化学成分间接测量提供真实环境成分指示的独立评估。科学影响将源自对NPF及其与云凝结核（CCN）浓度的联系的更好理解，而云凝结核浓度反过来又对降水模式和地球能量平衡产生重要影响。更广泛的教育影响将包括通过两名研究生的支持促进教学和学习。外展工作将包括通过一年一度的“海岸日”活动吸引更广泛的社区参与，期间首席研究员将介绍工作的某些方面。