EAGER: Measurement of the Oxygen and Hydrogen Isotope Composition of Evaporating Water Using a Novel Cavity Ring-Down Technique

主要研究者（PI）计划：（1）完善并应用一种新的实验技术来测量与蒸发和冷凝相关的水的动力学同位素分馏;（2）用传统的质谱技术校准所述仪器，重点是相对较低的水蒸气浓度（6000 ppmv）和水蒸气的氘过量。 预计这两个目标将有利于对水文学和大气气候动力学感兴趣的广大科学家。 PI开发了一种新的实验技术，用于测量与蒸发和冷凝相关的分馏，该技术利用了新的商用激光腔衰荡光谱仪（CRDS）的快速分析能力。 新技术与传统质谱法相比具有几个优点，因为可以同时实时测量水蒸气浓度和水蒸气氢和氧同位素比率。 初步的蒸发数据证实了已发表的平衡分馏（100%相对湿度），这表明这种方法可能提供一种新的方式，以促进了解同位素分馏过程中的不平衡蒸发和冷凝。这项工作是探索性的，其方法在很大程度上未经测试，因此符合EAGER的要求。这项工作将为今后广泛的水文和大气研究奠定基础。在这个项目中开发的研究方法将发表在同行评审的期刊上，并在国家会议上提出，该项目将部分资助博士学位。一个女博士的研究学生.

The Principal Investigator (PI) plans to: (1) To refine and apply a new experimental technique to measurements of the kinetic isotopic fractionation of water associated with evaporation and condensation; and (2) to calibrate a said instrument with traditional mass spectrometry techniques focusing on relatively low water vapor concentrations (6000 ppmv) and on the deuterium excess of water vapor. It is expected that both of these goals will be beneficial to a wide range of scientists with interest in hydrology and atmospheric climate dynamics. The PI has developed a novel experimental technique for measuring the fractionation associated with evaporation and condensation that takes advantage of the rapid analytical capabilities of newly commercially available laser-based cavity ring-down spectrometers (CRDS). The new technique has several advantages over traditional mass spectrometry as simultaneous, real-time measurements of water vapor concentration and water vapor hydrogen and oxygen isotopic ratios may be made. Preliminary evaporation data corroborate the published equilibrium fractionations (100% relative humidity), suggesting that this approach may provide a new way to advance understanding of isotopic fractionation during disequilibrium evaporation and condensation. This work is exploratory in nature and the approach largely untested and thus qualifies for an EAGER. This work will provide a foundation for future research in a wide range of hydrologic and atmospheric research. The research methodologies developed in this project will be published in peer-reviewed journals and presented at national conferences, and the project will partially fund the Ph.D. research of a female Ph.D. student.