Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole

合作研究：南极冰芯冰的三氧同位素和氢同位素组成记录

• 批准号: 1443328
• 负责人: James White
• 金额: $ 26万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1443328&HistoricalAwards=false
• 关键词: Collaborative; Research; Record; Triple; oxygen

This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible.This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.

该项目将创建来自南极南极冰芯的稳定相异位比率的记录。水 - 同位素比的测量提供了确定温度变化的手段。 南极与南极洲的大多数其他位置不同，在最近几十年中没有显示任何变暖，但是在1957年安装天气站之前，该位置的温度可变性知之甚少。作为该项目的一部分进行的测量值将导致温度较长的记录，将导致更长的温度记录，至少延长40，000年的时间，可帮助我们了解什么能够控制南方的南方脉络群，并改善了未来蚂蚁的变化。该项目的数据对于在南极冰核心工作的其他研究人员以及其他科学家和公众的普遍关注至关重要。 数据将迅速向其他调查人员提供，并尽快公开。该项目将获得目前在南极获得的冰核上稳定的水比的记录。核心将达到1500 m的深度，年龄为40，000年。该项目将使用激光光谱法获得氧气的超高分辨率记录，氧气为18/16和氘 - 氢比率，以及氧气17/16比率的低分辨率记录。高分辨率测量将用于帮助约会核心，并提供限制FIRN致密化过程的同位素扩散的估计。由于温度依赖性的过饱和比，新颖的17/16测量对同位素分馏提供了其他限制，这会影响液固凝结液转变过程中水的分馏。总之，这些技术将可以提高使用水同位素比作为冰片温度，海面温度和大气循环的代理的准确性。结果将是在南极东部的气候明显地区中通过百年纪念和千禧年气候变化的际际气候变化的记录，这先前尚未被深冰加芯采样。该项目将支持一名研究生，该研究生将由华盛顿大学和科罗拉多大学的教职员工共同努力，并将参与工作的各个方面。