Laboratory Studies of Ice Nucleation

冰成核的实验室研究

• 批准号: 1048536
• 负责人: Margaret Tolbert
• 金额: $ 52.06万
• 依托单位: University of Colorado at Boulder
• 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 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1048536&HistoricalAwards=false
• 关键词: Laboratory; Studies; Ice; Nucleation

Laboratory studies will examine heterogeneous ice nucleation and provide fundamental data to improve understanding of ice formation in the atmosphere. First, ice nucleation will be probed on particles relevant for the climate sensitive tropical tropopause layer (TTL) where recent work has identified particles composed mainly of sulfate and organic compounds as the main type responsible for ice nucleation. A range of organic compounds with different water solubility will be studied to probe how they influence ice nucleation. New studies on organic compounds that form glassy solids will provide additional insight into chemistry in the cold TTL. Next, heterogeneous ice nucleation on mineral particles representative of atmospheric dust will be studied. While dust is a well-known atmospheric ice nucleus, there is uncertainty about how coatings that form on the dust as it ages affect its ability to nucleate ice. Raman microscopy will be used to determine how the chemical composition, thickness and morphology of the coatings influence ice nucleation. Finally, experiments using Raman microscopy will characterize the ice nucleating ability of aerosols collected in the field. Ice nucleation on atmospheric samples will be used to select the particles most amenable to ice nucleation for detailed study using Raman spectroscopy and mapping.Cirrus clouds, composed of water ice, cover up to 30% of the Earth's surface at any time and sub-visible cirrus are almost always present in the TTL. These clouds play an important role in the climate system as well as in controlling the amount of water entering the stratosphere. While the net effect of cirrus clouds on climate is usually a warming at the surface, the microphysical properties of the clouds dictate their overall climatic impact. The microphysical properties depend, in turn, on the nucleation mechanism of ice in the atmosphere. In addition to performing fundamental research on ice nucleation, this project will give students, particularly women, the opportunity to gain skills in research and teaching that will further their scientific careers in atmospheric chemistry and physics. The project will provide an opportunity to integrate research and teaching at the University of Colorado by bringing undergraduates and graduate students into the laboratory to work side-by-side with more senior researchers. The experience they gain will help widen their perspective and give them valuable research experience that will be useful to them in a variety of future careers.

实验室研究将检查异质冰成核，并提供基本数据，以提高对大气中冰形成的理解。首先，冰成核将在与气候敏感的热带对流层顶层（TTL）相关的颗粒上进行探测，最近的工作已经确定了主要由硫酸盐和有机化合物组成的颗粒是冰成核的主要类型。将研究一系列具有不同水溶性的有机化合物，以探讨它们如何影响冰成核。对形成玻璃状固体的有机化合物的新研究将为冷TTL中的化学提供更多的见解。接下来，将研究代表大气尘埃的矿物颗粒上的非均质冰成核。虽然尘埃是一种众所周知的大气冰核，但随着年龄的增长，尘埃上形成的涂层如何影响其成核能力还不确定。拉曼显微镜将用于确定涂层的化学成分、厚度和形态如何影响冰成核。最后，使用拉曼显微镜的实验将表征在现场收集的气溶胶的冰成核能力。大气样品上的冰成核将用于选择最适合于冰成核的粒子，以使用拉曼光谱和绘图进行详细研究。由水冰组成的卷云在任何时候都覆盖多达30%的地球表面，并且在TTL中几乎总是存在亚可见卷云。这些云在气候系统中起着重要作用，并控制着进入平流层的水量。虽然卷云对气候的净效应通常是地表变暖，但云的微物理特性决定了它们对气候的总体影响。微物理性质反过来又取决于大气中冰的成核机制。除了对冰成核进行基础研究外，该项目还将使学生，特别是妇女，有机会获得研究和教学技能，这将促进他们在大气化学和物理学方面的科学事业。该项目将为科罗拉多大学的研究和教学提供一个机会，让本科生和研究生进入实验室，与更资深的研究人员并肩工作。他们获得的经验将有助于拓宽他们的视野，并为他们提供宝贵的研究经验，这将有助于他们在未来的各种职业生涯。