CAREER: Water and Energy Cycle Research and Education from the Stable Water Isotope Budget Near a Tall Tower in the Colorado Front Range

职业：科罗拉多州弗兰特山脉附近一座高塔附近稳定水同位素收支的水和能源循环研究和教育

• 批准号: 1539234
• 负责人: David Noone
• 金额: $ 21.79万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-13 至 2017-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1539234&HistoricalAwards=false
• 关键词: CAREER; Water; Energy; Cycle; Research

This project will observe and analyze the stable isotope composition of water vapor and precipitation, primarily at the 300 meter Boulder Atmospheric Observatory tower. The measurements will be made using an optical measurement technology which has only recently become available, and which allows continuous in-situ observations to be made on a practical basis. Further measurements will be taken of the size distribution of precipitation hydrometeors at the top and bottom of the tower, as well as measurements of the surface fluxes of sensible and latent heat (using a sonic anemometer and a high speed hygrometer) and soil heat flux (using a conductive plate). These measurements will complement existing measurements of carbon monoxide (CO), and carbon dioxide (CO2), and meteorology at the tower, and the water vapor measurements would be taken at the same heights as the CO and CO2 measurements, at 22, 100, and 300 meters. In addition, measurements of the isotopic composition of precipitation and soil water would be taken by students at several middle schools in the region and analyzed for isotopic composition. The middle schools will also be supplied with meteorological observing stations, and students will take meteorological measurements and receive instruction on atmospheric processes and the science of isotope hydrology. The research seeks to evaluate 1) the role of rainfall evaporation (virga) in controlling the isotopic composition and humidity of the summertime boundary layer, 2) the partioning of the surface energy and water fluxes, through isotopic constraints on the transpiration fraction of surface latent heating, and 3) the degree to which pairing water isotope measurements with other gas measurements, such as CO2 concentration, yield improved estimates of gas exchange between the surface and the overlying atmosphere. The measurements will be used to constrain and validate simulations from the Community Land and Community Atmosphere Models.The isotopic composition of precipitation and water vapor contains a wealth of useful information, including the temperature at which evaporation occurs over the ocean, the extent to which evapotranspiration over land serves as a source for subsequent precipitation (i.e. the strength of the land-atmosphere coupling), the pathways of water vapor transport in the atmosphere, and the strength of trace gas exchange (including CO2) between land and atmosphere. But the multitude of factors determining isotopic composition makes it difficult to extract the useful information, particularly given our limited quantitative understanding of some of the physical processes. Research conducted under this project will thus serve the climate science community by helping to deconvolve the factors determining isotopic composition, and unlock the valuable climatological information contained in it. In addition, the participation of middle school students in the project will serve the general public, including underrepresented groups, in surrounding communities by offering an early exposure to scientific research. Educational activities will also take place at the University of Colorado involving graduate and undergraduate students, including a project in which engineering students design and build a mechanical device to collect rain and snow samples.

该项目将观察和分析水蒸气和降水的稳定同位素组成，主要是在300米高的博尔德大气观测塔。测量将使用一种光学测量技术进行，这种技术最近才出现，可以在实际的基础上进行连续的现场观测。将进一步测量塔顶和塔底降水水成物的大小分布，以及测量地表感热通量和潜热通量（使用声速风速计和高速湿度计）和土壤热通量（使用导电板）。这些测量将补充塔上现有的一氧化碳（CO）和二氧化碳（CO2）测量和气象学，水蒸气测量将在与CO和CO2测量相同的高度进行，分别为22米、100米和300米。此外，该地区几所中学的学生将测量降水和土壤水的同位素组成，并分析其同位素组成。中学还将配备气象观测站，学生将进行气象测量，并接受大气过程和同位素水文科学的指导。该研究旨在评估1)降雨蒸发（virga）在控制夏季边界层同位素组成和湿度方面的作用；2)通过对地表潜热蒸腾分数的同位素约束来分配地表能量和水通量；3)将水同位素测量与其他气体测量（如CO2浓度）配对的程度。提高了对地表和上覆大气之间气体交换的估计。这些测量结果将用于约束和验证社区土地和社区大气模式的模拟结果。降水和水蒸气的同位素组成包含了大量有用的信息，包括在海洋上空发生蒸发时的温度、陆地上的蒸散发作为后续降水来源的程度（即陆地-大气耦合的强度）、大气中水蒸气输送的途径以及陆地和大气之间微量气体交换（包括CO2）的强度。但是，决定同位素组成的因素很多，很难提取有用的信息，特别是考虑到我们对一些物理过程的定量理解有限。因此，在这个项目下进行的研究将通过帮助解开决定同位素组成的因素，并解开其中包含的有价值的气候学信息，为气候科学界服务。此外，中学生参与该项目将通过提供早期接触科学研究的机会，服务于周围社区的普通公众，包括代表性不足的群体。科罗拉多大学也将开展涉及研究生和本科生的教育活动，其中包括一个工程专业学生设计和建造一个收集雨雪样本的机械装置的项目。