AGS-PRF: Quantifying the Sources of Atmospheric Ice Nuclei from Biomass Burning and Fossil Fuel Combustion Aerosol

该奖项将允许博士后研究人员有机会研究大气冰核的来源和组成。冰核是一种小颗粒，在云中形成冰晶的效率特别高。大气中很少有颗粒具有这种特性，但它们对云和降水的影响很大。该合同的主要内容是测量由燃烧源产生的冰核，如农业燃烧、野火和车辆污染。冰核的数量和粒子形成冰晶的能力将被研究。该项目的最终结果将是更好地了解来自燃烧源的颗粒在云系统中的作用，并将改进的工具纳入从云尺度到全球尺度的数值模型中。该研究员还将促进大气科学与生物科学之间的跨学科研究，并指导一名暑期实习生，以加强本科生的培训和学习。碳质燃烧气溶胶的冰成核活性受到的约束很差，现场和实验室研究的结果相互矛盾。这项工作将通过在现场直接取样燃烧气溶胶和相关的实验室工作来解决这一缺点。主要使用的仪器是科罗拉多州立大学（CSU）连续流动扩散室（CFDC）测定冰核数浓度和单粒子烟尘光度计（SP2）选择性去除难熔黑碳。生物采样器也将用于确定生物颗粒和有机材料的贡献。选择的粒子将使用扫描电子显微镜和能量色散光谱（SEM-EDS）进一步评估。该项目的具体目标是：1)进行实验室实验，测试SP2仪器与CFDC耦合技术；2)测量俄克拉荷马州受控冬小麦燃烧的冰核；3)对科罗拉多州野火的冰核进行采样；4)对科罗拉多州高速公路附近的化石燃料燃烧进行采样；5)修改或创建新的云到全球尺度模型参数化。

This award will allow a postdoctoral researcher the opportunity to study the sources and composition of atmospheric ice nuclei. Ice nuclei are small particles that are especially efficient at forming ice crystals in clouds. Very few particles in the atmosphere have this property, but their effect on clouds and precipitation is large. The main aspect of this award will be the measurement of ice nuclei that originates from combustion sources, such as agricultural burning, wildfires, and vehicle pollution. The number of ice nuclei and the ability of the particles to form ice crystals will be studied. The end result of the project will be a better understanding of the role of particles from combustion sources in the cloud system, and an improved tool that will be incorporated into numerical models from the cloud scale to the global scale. The researcher will also promote cross-disciplinary research between the atmospheric and biological sciences, as well as mentor a summer intern in order to enhance undergraduate training and learning.The ice nucleation activity of carbonaceous combustion aerosol is poorly constrained, with conflicting results from both field and laboratory studies. This work will address this shortcoming through the direct sampling of combustion aerosols in the field, and associated laboratory work. The main instruments to be used are the Colorado State University (CSU) continuous flow diffusion chamber (CFDC) to determine the number concentration of ice nuclei and the single particle soot photometer (SP2) to selectively remove refractory black carbon. Biosamplers will also be used to determine the contribution of biological particles and organic materials. Select particles will be further assessed using Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM-EDS). The specific objectives of the project are to: 1) conduct laboratory experiments to test the technique of coupling the SP2 instrument to the CFDC, 2) measure ice nuclei from controlled winter wheat burns in Oklahoma, 3) conduct sampling of ice nuclei from wildfires in Colorado, 4) perform sampling of fossil fuel combustion near highways in Colorado, and 5) modify or create new parameterizations for cloud to global scale models.