Collaborative Research: Snow Transport in Katabatic Winds and Implications for the Antarctic Surface Mass Balance: Observations, Theory, and Numerical Modeling

合作研究：下降风中的雪输送及其对南极表面质量平衡的影响：观测、理论和数值模拟

• 批准号: 2034874
• 负责人: Scott Salesky
• 金额: $ 53.03万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034874&HistoricalAwards=false
• 关键词: Collaborative; Research; Snow; Transport; Katabatic

1. A non-technical explanation of the project's broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer.Katabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs.The Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps.2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. Using field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow.The numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate modelsThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

1. 对项目更广泛意义和重要性的非技术解释，作为 NSF 资助的公共理由。这部分内容对于受过教育但不是科学家或工程师的读者来说应该是可以理解的。下降风或排水风在重力作用下将高密度空气从较高海拔带下斜坡。 尽管下降流在高山和极地地区普遍存在，但目前缺乏这些流的表层相似性理论，从而损害了数值天气和气候预测模型的准确性。该项目是跨学科的，将为研究生和本科生提供与核心学科之外的研究人员互动的宝贵经验。此外，该项目将通过既定计划从 OU 和 CU 中代表性不足的群体中招募学生，扩大对科学的参与。南极冰盖通过调节区域和全球大气和海洋环流、储存，驱动地球系统中的许多过程。淡水的影响，以及对全球反照率和气候的影响。了解冰盖的表面质量平衡对于预测未来海平面上升和解释冰芯记录至关重要。然而，由于缺乏总体理论框架、缺乏现场观测数据集和缺乏总体理论框架，人们对冰盖通过积雪沉积、侵蚀和下降风（南极大部分地区持续存在）的迁移而发生的演变仍然知之甚少。缺乏准确的数值建模工具。鉴于预计南极大陆内未来将发生的气候和降雪变化，迫切需要提高对下降运输过程的基本理解和建模能力。该项目将利用多学科研究团队的专业知识（背景涵盖冰冻圈科学、环境流体力学和大气科学）来解决这些知识差距。2。项目的技术描述，说明要研究的问题、研究的目标和范围以及要使用的方法和途径。在许多情况下，技术项目描述可能是与提案一起提交的项目摘要的修改版本。通过现场观察和对下降流的直接数值模拟，该项目有望首次提出下降流的表层相似理论，将湍流通量与平均垂直梯度联系起来。相似理论将用于开发大涡模拟 (LES) 的表面边界条件，从而实现第一个精确的 LES 下降流。 PI 将开发的数值工具将使他们能够研究雪的重新分布、运输、运输之间的划分。升华取决于南极洲通常遇到的环境参数（例如大气层结、表面倾斜角度和湿度剖面），并开发简单的模型来基于卫星遥感和区域气候模型该奖项反映了 NSF 的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。