Towards a Molecular Understanding of Atmospheric Nucleation: Reactions of Amines with Sulfuric Acid Clusters

对大气成核的分子理解：胺与硫酸簇的反应

• 批准号: 1068201
• 负责人: Peter McMurry
• 金额: $ 69万
• 依托单位: University of Minnesota-Twin Cities
• 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: 2011-05-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1068201&HistoricalAwards=false
• 关键词: Towards; Molecular; Understanding; Atmospheric; Nucleation

Several new instruments will be used to explore the hypothesis that the high aerosol nucleation rates observed in the atmospheric boundary layer are primarily due to the reaction of amines with sulfuric acid molecular clusters. The cluster chemical ionization mass spectrometer (Cluster CIMS) measures the concentrations and masses of neutral molecular clusters produced by nucleation. The diethylene glycol condensation particle counter (DEG CPC), when used as the detector for an aerosol mobility spectrometer, allows measurements of particle mobility distributions down to 1 nanometer size. Parallel measurements with the Cluster CIMS allow definition of the complete spectrum of sizes down to one molecule. The ambient pressure proton transfer mass spectrometer (AmpMS) allows real-time measurements of amines. Computational chemistry will complement laboratory nucleation experiments and measurements in the atmosphere of Pittsburgh, PA by helping to elucidate processes that occur during chemical ionization in the Cluster CIMS as well as the thermodynamic and kinetic processes responsible for the formation of stable nuclei in the atmosphere.The formation of new particles by nucleation in the atmosphere affects concentrations of cloud nuclei and, therefore, the earth's albedo. Uncertainties in the cloud albedo effect are the largest source of uncertainty in climate models. Accounting for new particle production is one source of this uncertainty. This project will support two graduate students and a post-doctoral scholar as well as offer research experience opportunities to undergraduate students. Outreach activities will include presentations to and laboratory exercises with Minnesota school students, involvement in science camp efforts in collaboration with the Department of Chemistry's chapter of Women in Science and Engineering, and efforts to increase awareness of the health impacts of wood smoke emissions from cook stoves in developing countries.

几个新的仪器将被用来探索的假设，在大气边界层中观察到的高气溶胶成核率主要是由于胺与硫酸分子簇的反应。簇化学电离质谱仪（Cluster CIMS）测量由成核产生的中性分子簇的浓度和质量。二甘醇凝聚粒子计数器（DEG CPC），当用作气溶胶迁移率光谱仪的检测器时，允许测量小至1纳米尺寸的粒子迁移率分布。与Cluster CIMS的并行测量允许定义小至一个分子的完整光谱。环境压力质子转移质谱仪（AmpMS）允许实时测量胺。计算化学将补充匹兹堡大气中的实验室成核实验和测量，帮助阐明在集群CIMS中化学电离过程中发生的过程，以及在大气中形成稳定核的热力学和动力学过程。在大气中成核形成新粒子会影响云核的浓度，因此，地球的太阳云的不确定性是气候模式不确定性的最大来源。对新粒子产生的解释是这种不确定性的一个来源。该项目将支持两名研究生和一名博士后学者，并为本科生提供研究经验的机会。外联活动将包括向明尼苏达州学校学生介绍情况和进行实验室练习，与化学系科学和工程界妇女分会合作参与科学营活动，以及努力提高对发展中国家炉灶产生的木烟排放对健康影响的认识。