Development of a Laser Spectroscopy System for Analysis of 17Oexcess on Ice Cores

Steig/1341360该奖项支持一个为期两年的项目，以开发一种快速精确测量水中18 O/16 O和17 O/16 O同位素比值差异的方法，称为17 O过量。 测量17 O-过剩是地球化学中的一项最新创新，补充了氢（D/H）和氧（18 O/16 O）比值的传统测量。传统的17 O/16 O测量方法数量有限，因为分析耗时费力，包括通过重离子交换将水转化为氧气，然后进行高精度质谱分析。 该项目将使用由华盛顿大学和Picarro公司共同开发的新型光腔衰荡光谱系统。（圣克拉拉，加利福尼亚州），沿着冰与气候中心（尼尔斯玻尔研究所，哥本哈根）。 该研究的主要智力价值是改进了用于测量17 Oexcess离散水样品的CRDS方法，以获得与使用质谱的常规方法竞争的精密度和准确度。这将通过量化水蒸气浓度变化和仪器记忆的影响、根据标准沃茨精确校准仪器以及改进光谱分析来实现。CRDS系统还将与位于博尔德的科罗拉多大学合作，与用于冰芯分析的连续流系统相连接。目标是拥有一个可用于与下一个美国主要核试验相关的冰芯处理的操作系统。2015-2017年，领导南极冰芯项目。 该研究的更广泛影响包括测量环境大气水蒸气中17 O过量的能力，这可用于提高对对流，水分传输和冷凝的理解。 这里提出的仪器开发工作是相关的研究支持的几个国家科学基金-地球观测组织计划，包括水文，气候和大尺度动力学，古气候，大气化学，北极和南极计划。该项目将资助一名博士后研究员。

Steig/1341360This award supports a two-year project to develop a method for rapid and precise measurements of the difference in 18O/16O and 17O/16O isotope ratios in water, referred to as the 17O-excess. Measurement of 17O-excess is a recent innovation in geochemistry, complementing traditional measurements of the ratios of hydrogen (D/H) and oxygen (18O/16O). Conventional measurements of 17O/16O are limited in number because of the time-consuming and laborious nature of the analyses, which involves the conversion of water to oxygen via fluorination, followed by high-precision mass spectrometry. This project will use a novel cavity ring-down spectroscopy (CRDS) system developed by a joint effort of the University of Washington and Picarro, Inc. (Santa Clara, CA), along with the Centre for Ice and Climate (Neils Bohr Institute, Copenhagen). The primary intellectual merit of the research is the improvement of the CRDS method for measurements of 17Oexcess of discrete samples of water, to obtain precision and accuracy competitive with conventional methods using mass spectrometry. This will be achieved by quantification of the effects of water vapor concentration variability and instrument memory, precise calibration of the instrument against standard waters, and improvements to the spectroscopic analyses. The CRDS system will also be coupled to continuous-flow systems for ice core analysis, in collaboration with the University of Colorado, Boulder. The goal is to have an operational system available for ice core processing associated with the next major U.S.-led ice core project at South Pole, in 2015-2017. The broader impacts of the research include the ability to measure 17O-excess in ambient atmospheric water vapor, which can be used to improve understanding of convection, moisture transport, and condensation. The instrument development work proposed here is relevant to research supported by several NSF-GEO programs, including Hydrology, Climate and Large Scale Dynamics, Paleoclimate, Atmosphere Chemistry, and both the Arctic and Antarctic Programs. This proposal will support a postdoctoral researcher.