RUI: Cirrus Ice Crystal Surface Structure and Kinetics at the Nanoscale

RUI：纳米尺度的卷云冰晶表面结构和动力学

• 批准号: 1501096
• 负责人: Nathan Magee
• 金额: $ 19.77万
• 依托单位: The College of New Jersey
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501096&HistoricalAwards=false
• 关键词: RUI; Cirrus; Ice; Crystal; Surface

The role of cirrus clouds in the radiative balance of the climate system is still a poorly constrained problem. The successful modeling of cirrus coverage, cloud evolution, and response to a changing climate has been limited by fundamental uncertainties in the microphysics of the constituent ice particles. Important questions remain regarding cirrus ice particle nucleation, growth and sublimation efficiency, and particle morphology. This project will address two of these fundamental uncertainties through novel use of modern nanotechnology tools. First, do ice crystal facets in cirrus clouds exhibit roughened surfaces at the nanoscale and microscale, and if so, what factors affect the degree and character of roughening? Secondly, does the presence or absence of roughened surfaces alter predicted rates of water vapor-ice phase exchange?Intellectual Merit:Improved modeling of cirrus clouds is of widely acknowledged strategic importance for climate modeling, and there is broad agreement that a paucity of laboratory measurements of ice microphysics is among the most significant constraints on progress. Aircraft probes and cloud chambers are making advances, but one avenue of potential discovery remains largely untapped: modern materials imaging and analysis tools have yet to be fully applied to ice surfaces under atmospherically relevant conditions. Such analysis can be expected to reveal new information about ice crystal surface structures and kinetics. Preliminary data acquired by Environmental Scanning Electron Microscopy (ESEM) have already demonstrated the ubiquitous presence of ice surface roughness in lab-grown crystals, and revealed growth rates that deviate from classical predictions. However, the ice crystals already analyzed by ESEM have been made on a substrate in a pure vapor environment; the relevance of these findings to the atmosphere cannot be fully established without a revised experimental approach. This project aims to address this question head-on by conducting laboratory experiments under gaseous conditions more representative of the atmosphere and through balloon-borne capture, retrieval, and analysis of actual cirrus particles. Successful completion of the project will firmly establish the character of surface roughness on cirrus particles, contribute to improved modeling of vapor deposition/sublimation, and provide the clearest, highest-resolution images of cirrus ice particles ever acquired.Broader Impacts:This project will be conducted by physics department faculty and students at a primarily undergraduate institution, The College of New Jersey (TCNJ), in Ewing, NJ. Undergraduate research has proven to be a highly effective tool for recruiting outstanding students into careers in the field of atmospheric science. Largely because of the relative scarcity of undergraduate programs, the atmospheric sciences lag behind other natural sciences in developing this pipeline. This project will help to more firmly establish atmospheric science within the physics department at TCNJ, a large and growing department. By providing cutting-edge research opportunities to outstanding physics undergraduates, the project will pave the way for an under-utilized path into careers in atmospheric science. In addition, during each year, two of the undergraduate researchers in the program will be dual science/secondary education students who will carry the excitement of scientific discovery into their high school classrooms. These future teachers will engage high school students from the high-need school districts of Trenton and Ewing, New Jersey in inquiry-centered laboratory experiences based on the scientific questions being addressed in the proje

卷云在气候系统辐射平衡中的作用仍然是一个限制很小的问题。卷云覆盖率、云层演变和对气候变化的响应的成功模拟一直受到构成冰粒的微观物理中的基本不确定性的限制。有关卷云冰颗粒成核、生长和升华效率以及颗粒形态的重要问题仍然存在。这个项目将通过现代纳米技术工具的新颖使用来解决其中两个根本的不确定性。首先，卷云中的冰晶面是否在纳米和微米尺度上表现出粗糙的表面，如果是，影响粗糙程度和性质的因素是什么？其次，粗糙表面的存在或不存在是否改变了水蒸气-冰相交换的预测速率？智力上的好处：改进的卷云模拟对于气候模拟具有广泛的战略重要性，而且人们普遍认为，缺乏对冰微物理的实验室测量是进展的最重大限制之一。飞机探测器和云室正在取得进展，但有一条潜在的发现途径在很大程度上仍未开发：现代材料成像和分析工具尚未完全应用于与大气相关的条件下的冰面。这样的分析有望揭示有关冰晶表面结构和动力学的新信息。环境扫描电子显微镜(ESEM)获得的初步数据已经证明，实验室生长的晶体中普遍存在冰表面粗糙度，并揭示了与经典预测相背离的生长速度。然而，环境扫描电子显微镜已经分析的冰晶是在纯蒸汽环境中的衬底上制成的；如果没有经过修订的实验方法，这些发现与大气的相关性就不能完全确定。该项目旨在正面解决这一问题，方法是在更能代表大气的气体条件下进行实验室实验，并通过气球对实际卷云粒子进行捕获、提取和分析。该项目的成功完成将巩固卷云颗粒表面粗糙度的特征，有助于改进对蒸气沉积/升华的建模，并提供有史以来获得的最清晰、最高分辨率的卷云冰颗粒图像。广泛影响：该项目将由新泽西州尤因的一所主要本科院校--新泽西学院(TCNJ)的物理系教职员工和学生进行。本科生研究已被证明是招募优秀学生进入大气科学领域职业生涯的一个非常有效的工具。在很大程度上，由于本科课程的相对匮乏，大气科学在发展这一管道方面落后于其他自然科学。该项目将有助于在TCNJ的物理系内更牢固地建立大气科学，TCNJ是一个规模庞大且不断增长的系。通过为杰出的物理学本科生提供尖端研究机会，该项目将为进入大气科学职业生涯铺平道路。此外，在每年期间，该项目中的两名本科生研究人员将是理科/中等教育双重教育的学生，他们将把科学发现的兴奋带入高中课堂。这些未来的教师将让来自新泽西州特伦顿和尤因等高需求学区的高中生参与以探究为中心的实验室体验，基于项目中正在解决的科学问题