Numerical and experimental investigation of the impact of preferential flow and nonequilibrium thermodynamics on meltwater transport through snow

优先流和非平衡热力学对融水通过雪输送影响的数值和实验研究

• 批准号: 2243631
• 负责人: Xiaojing Fu
• 金额: $ 45.47万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2243631&HistoricalAwards=false
• 关键词: Numerical; experimental; investigation; impact; preferential

Water stored in terrestrial snowpack is an essential buffer in hydrological systems. Extreme weather events induced by climate change, such as frequent heat waves and prolonged droughts, have made it difficult for current water resource models to accurately predict the timing and volume of snowmelt arrival in groundwater and surface water systems. Improving the mechanistic understanding of snowmelt transport is a key component in building a more robust prediction platform to better manage water resources under climate variability. This project will contribute to the education of undergraduate and graduate students learning state-of-art modeling methods and computer simulation programs and will provide students with the experience of developing novel laboratory experiments. This project will generate fundamental knowledge on how the percolation of meltwater interacts with the porous structure of snowpack under various environmental conditions, and how such interactions influence the volume and timing of melt drainage into the underlying groundwater system. Existing models of snowmelt transport are limited by simplified flow physics and equilibrium thermodynamics, which fail to address important field observations. This project will use a new model to systematically investigate melt transport in heterogeneous environments under dynamic atmospheric conditions. The model resolves important physics missing in previous models that significantly influence the residence time of melt within snowpack during transport. Additionally, observations of melt transport through snow under controlled environmental conditions have only been made in 3D snow samples, rendering quantitative comparison with numerical models challenging. This project will design and perform controlled laboratory experiments to directly visualize real-time dynamics of melt transport and refreezing in quasi-2D flow cells. The combined numerical-experimental effort will provide new insights on meltwater transport and storage within snowpack, which is necessary to improve parameterization of snowmelt processes in large-scale hydrological models.This 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.

陆地积雪中储存的水是水文系统中必不可少的缓冲水。由气候变化引起的极端天气事件，如频繁的热浪和长期干旱，使得目前的水资源模型难以准确预测地下水和地表水系统融雪的时间和数量。提高对融雪运输机制的认识是建立更可靠的预测平台以更好地管理气候变率下水资源的关键组成部分。该项目将有助于教育本科生和研究生学习最先进的建模方法和计算机仿真程序，并将为学生提供开发新颖实验室实验的经验。该项目将产生关于在各种环境条件下融水的渗透如何与积雪的多孔结构相互作用的基础知识，以及这种相互作用如何影响融水排入地下地下水系统的体积和时间。现有的融雪输送模型受限于简化的流动物理和平衡热力学，无法处理重要的野外观测。该项目将使用一个新的模型系统地研究在动态大气条件下异质环境中的熔体输送。该模式解决了以往模式中缺失的重要物理现象，这些物理现象在运输过程中对积雪内融化的停留时间有显著影响。此外，在受控环境条件下，融水通过雪的运输观测仅在三维雪样品中进行，这使得与数值模型的定量比较具有挑战性。该项目将设计并执行受控实验室实验，直接可视化准二维流动池中熔体传输和再冻结的实时动力学。数值与实验相结合的研究成果将为研究融水在积雪中的运输和储存提供新的见解，这对改善大尺度水文模型中融水过程的参数化是必要的。该奖项反映了美国国家科学基金会的法定使命，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。

项目成果

A Thermodynamic Nonequilibrium Model for Preferential Infiltration and Refreezing of Melt in Snow

雪中​​熔体优先渗透和再冻结的热力学非平衡模型

• DOI: 10.1029/2022wr034035
• 发表时间: 2023
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Moure, Adrian;Jones, Nathan;Pawlak, Joshua;Meyer, Colin;Fu, Xiaojing
• 通讯作者: Fu, Xiaojing