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

卷云在气候系统辐射平衡中的作用仍然是一个缺乏约束的问题。成功模拟卷云覆盖、云演化和对气候变化的响应受到构成冰粒微物理学基本不确定性的限制。重要的问题仍然是关于卷云冰颗粒的成核，生长和升华效率，以及颗粒形态。该项目将通过对现代纳米技术工具的新颖使用来解决其中两个基本的不确定性。首先，卷云中的冰晶面在纳米尺度和微尺度上是否表现出粗糙的表面，如果是，是什么因素影响了粗糙的程度和特征？其次，粗糙表面的存在或不存在是否会改变水蒸气-冰相交换的预测速率？知识价值：改进的卷云建模对气候建模具有广泛的战略重要性，并且普遍认为缺乏冰微物理的实验室测量是对进展的最重要限制之一。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仍未得到充分开发：现代材料成像和分析工具尚未完全应用于与大气相关条件下的冰表面。这样的分析有望揭示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，在实验室生长的晶体中，冰表面粗糙度无处不在，并且揭示了与经典预测不同的生长速度。然而，已经被ESEM分析的冰晶是在纯蒸汽环境下的衬底上制造的；如果不修改实验方法，就不能完全确定这些发现与大气的相关性。该项目旨在通过在更能代表大气的气体条件下进行实验室实验，以及通过气球运载的捕获、检索和分析实际卷云颗粒，来正面解决这个问题。该项目的成功完成将牢固地建立卷云颗粒表面粗糙度的特征，有助于改进气相沉积/升华建模，并提供有史以来最清晰、最高分辨率的卷云冰粒图像。更广泛的影响：该项目将由新泽西州尤因的新泽西学院（TCNJ）的物理系教师和学生进行。本科生研究已被证明是招募优秀学生进入大气科学领域的一个非常有效的工具。很大程度上是因为本科课程的相对稀缺，大气科学在发展这一管道方面落后于其他自然科学。这个项目将有助于更牢固地建立大气科学在物理系的TCNJ，一个庞大的和不断发展的部门。通过为优秀的物理学本科生提供前沿研究机会，该项目将为未充分利用的大气科学职业道路铺平道路。此外，每年，该项目的两名本科研究人员将是科学/中学双重教育的学生，他们将把科学发现的兴奋带进高中教室。这些未来的教师将吸引来自新泽西州特伦顿和尤因高需求学区的高中生参与以探究为中心的实验室体验，这些实验室体验基于项目中正在解决的科学问题

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