Collaborative Research: An Experimental and Modeling Study of Inverse-Temperature Layer and Its Effect on Evaporation over Water Surfaces

蒸发是地球系统中连接水、能量和碳循环的独特重要过程。监测和模拟湖泊和海洋等水面上的蒸发仍然具有挑战性。更好地量化和模拟水分蒸发需要更好地了解水-大气界面的物理过程。一个突出的科学问题是温度随深度增加的顶层水层（称为逆温层）在蒸发中的作用。一个由水文气象学家和流体力学科学家组成的跨学科团队将使用尖端的现场和数值实验技术以及各种建模工具来解决这个问题。该项目的成果将使地球科学的广泛领域受益，特别是水-能量-碳循环的研究。本项目将培养研究生获得全面的研究经验。三所参与大学将为不同种族背景的理工科高中生和大学生提供小型项目、系列研讨会和暑期培训课程，项目目标是通过实地实验，了解水体顶部逆温层动态的物理机制及其对水面日和季节蒸发的影响，大涡模拟，理论和模型分析。该项目将在内陆湖泊上使用一个最先进的科学设施，测量高分辨率水温剖面、水上方和水内部的动量/热量/水团通量以及水文气象变量，以揭示逆温度层的行为。项目小组将进行大涡流模拟，以了解大气过程与调节逆温层和蒸发的水中流体动力学/热力学之间的机械联系。该小组还将利用实地和模拟数据来评估陆地-海洋-大气耦合模型中蒸发的经典和最近开发的参数化的性能。研究结果将通过期刊论文和会议报告传播给科学界，以促进对地球科学的长期主题和全球内陆沃茨和相关水生生态系统的碳排放等新出现的关键问题进行更多的合作研究。建议的工作包括博士生参与研究，将研究成果融入PI教授的本科和研究生课程，以及K-12推广。该项目由水文科学和物理与动力气象学项目共同资助。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。

Evaporation is a uniquely important process in the Earth System linking water, energy, and carbon cycles. Monitoring and modeling evaporation over water surfaces such as lakes and oceans remains challenging. Better quantification and modeling of water evaporation requires improved understanding of the physical processes across the water-atmosphere interface. An outstanding scientific question is the role of the top water layer where temperature increases with depth, known as the inverse-temperature layer, in evaporation. An interdisciplinary team of hydro-meteorologists and fluid mechanics scientists will use cutting-edge field and numerical experiment technology and various modeling tools to address this question. The outcomes from this project will benefit broad fields of the Earth Sciences, especially the study of water-energy-carbon cycles. This project will train graduate students to gain all-around research experience. The three participating universities will offer mini projects, seminar series, and summer training courses for high school and college students with diverse ethnic backgrounds pursuing science and engineering education.The project objective is to understand the physical mechanisms underlying the dynamics of the inverse-temperature layer on the top of water-bodies and its effect on evaporation over water surfaces at diurnal and seasonal scales through field experiments, large-eddy simulations, and theoretical and modeling analysis. The project will use a state-of-the-science facility over an in-land lake to measure high-resolution water temperature profiles, above- and in-water fluxes of momentum/heat/water mass and hydro-meteorological variables to reveal the behavior of the inverse temperature layer. The project team will conduct large-eddy simulations to understand the mechanistic links between atmospheric processes and in-water fluid dynamics/thermodynamics regulating the inverse temperature layer and evaporation. The team will also use field and simulation data to evaluate the performance of classical and recently developed parameterizations of evaporation in coupled land-ocean-atmosphere models. The findings will be disseminated to scientific communities through journal papers and conference presentations to promote more collaborative research on both long-lasting topics of geosciences and critical emerging issues such as carbon emissions from global inland waters and associated aquatic eco-systems. The proposed work includes engagement of PhD students in research, integration of research findings into undergraduate and graduate courses taught by the PIs, and K-12 outreach.This project is co-funded by the Hydrologic Sciences and Physical and Dynamic Meteorology programs.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.