CAREER: Multi-Scalar Transport and Similarity in the Urban Boundary Layer

职业：城市边界层的多标量交通和相似性

• 批准号: 2143664
• 负责人: Qi Li
• 金额: $ 54.94万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2143664&HistoricalAwards=false
• 关键词: CAREER; Multi; Scalar; Transport; Similarity; CAREER; Multi; Scalar; Transport; Similarity

More than half of the global population live in urban areas, which nontrivially modify the atmosphere through two broad pathways: urban form (i.e., changes in surface properties) and urban function (i.e., anthropogenic activities emitting heat and mass). These two pathways occur via turbulent exchanges of momentum, energy and mass in the atmospheric boundary layer and carry ‘distinct fingerprints’ of a city’s form and function. For increasingly fine-scale climate and numerical weather prediction (NWP) models, it is a persistent challenge to reflect these ‘distinct fingerprints’ of different cities across the world, yet in a manner that is generalizable and computationally tractable. Due to incomplete understanding of multi-scalar transport, whether different scalars of anthropogenic origins obey similarity relations in the urban surface layer remains unclear. This is also one of the key stumbling blocks to generalize urban land-atmosphere exchanges for multiple scalars. In particular, incorporating the effect of urban function on surface-atmosphere exchanges into climate and NWP models is almost completely missing. Therefore, the overarching goal is to improve basic understanding of multi-scalar transport and inform physically realistic, generalizable estimates of the surface-atmosphere exchanges, especially for less explored scalars. The project will lead to findings necessary for the next-generation urban climate modeling tools, which can be implemented to develop more precise (i.e., city or neighborhood-specific) mitigation and adaptation measures with changing climates. To achieve the overall project goal, the approach of this project is motivated by a critical comparison between flow and transport in the urban canopy versus vegetated one, which has been extensively studied. Such an approach will generate new insight into the transferability of theories and models between the two, informing development of urban-specific models for surface-atmosphere exchanges based on the existing ones for vegetation counterpart. To advance basic understanding of multi-scalar transport and departure from similarity, the mechanisms responsible for scalar dissimilarity will be separately investigated at the micro- and local scale of heterogeneities in urban form and function. Understanding of multi-scalar transport at both the micro- and local scales will be systematically studied by first deriving a ‘city profile generation’ module to generalize urban form and function (Aim 1). Then, hypotheses regarding multi-scalar transport and their similarity will be tested to advance basic understanding (Aim 2). The new understanding will help improve urban surface-atmosphere exchange modeling and interpretation of observations that rely on scalar similarity theory (Aim 3).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.

超过一半的全球人口居住在城市地区，这些地区通过两种广泛的途径非试图修改大气：城市形式（即表面特性的变化）和城市功能（即，发出热量和质量的人为活动）。这两种途径通过大气边界层的动量，能量和质量的湍流交换出现，并带有城市形式和功能的“不同的指纹”。对于越来越高的气候和数字天气预测（NWP）模型，反映世界各地不同城市的这些“独特的指纹”是一个持续的挑战，但是以一种可推广和计算障碍的方式。由于对多量表转运的不完全了解，人为起源的不同标量是否符合城市表面层中的相似性关系尚不清楚。这也是概括多个标量的城市土地大气交换的关键绊脚石之一。特别是，将城市功能对地表 - 大气交换的影响纳入气候和NWP模型几乎完全缺失。因此，总体目标是提高对多量表运输的基本理解，并为表面 - 大气交换的物理现实，可概括的估计提供信息，尤其是对于较少探索的标量。该项目将导致下一代城市登山者建模工具所必需的发现，可以实施这些工具，以开发更精确的（即城市或特定于邻里的）缓解措施，并随着气候的变化而采取适应性措施。为了实现总体项目目标，该项目的方法是由城市顶篷的流量与运输与植被的批判性比较进行的，该植被已广泛研究。这种方法将对两者之间的理论和模型的可传递性产生新的见解，从而为基于现有的蔬菜对应物的现有蔬菜交换而开发了城市特异性模型。为了促进对多量表运输和偏离相似性的基本理解，将在城市形式和功能的异质性的微观和局部尺度下分别研究负责标量差异的机制。通过首先得出“城市档案生成”模块来概括城市形式和功能，了解微观和本地尺度的多量表传输将被系统地研究（AIM 1）。然后，将测试有关多量表运输及其相似性的假设以提高基本理解（AIM 2）。新的理解将有助于改善依赖标量相似性理论的观测值的城市地表 - 大气交换建模和解释（AIM 3）。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响评估标准来评估值得支持。