Collaborative Research: Cosmogenic Radionuclides in the WAIS Divide Ice Core

合作研究：WAIS 分水岭冰芯中的宇宙放射性核素

• 批准号: 0636964
• 负责人: Kees Welten
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-15 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0636964&HistoricalAwards=false
• 关键词: Collaborative; Research; Cosmogenic; Radionuclides; WAIS

Welten/0636964This award supports a 2-year project to measure the concentrations of the cosmogenic radionuclides, 10Be, 26Al and 36Cl, in Antarctic ice samples using accelerator mass spectrometry (AMS). This project is a pilot study for the future analysis of radionuclides from up to 1000 individual ice samples of the WAIS Divide deep ice core. Because of the large number of samples that are involved in these ice core studies, and the importance of a timely analysis of cosmogenic radionuclides, we are proposing to set up a second chemical separation line, at Purdue University, identical to the one developed at UC Berkeley for the Siple Dome and GISP-2 ice cores. After a thorough interlaboratory comparison on 12-16 test ice samples, we will use both extraction lines to measure cosmogenic radionuclides in a shallow ice core from the WAIS Divide. It is to be expected that the use of two chemical separation lines will increase the sample throughput by a factor of two, and ensure a timely analysis of the cosmogenic radionuclides by AMS at Purdue University. The intellectual merit of the project is that these measurements will enable scientists to separate local from global effects. By measuring several radionculides in ice cores from different locations one can disentangle whether variations in absolute radionuclide concentrations and their ratios are due to local effects such as variations in atmospheric circulation, deposition mechanisms, and snow accumulation rates; or whether they are due to variations in solar activity and geomagnetic field strength, the primary processes influencing the global production rates of cosmogenic nuclides in the atmosphere. Finally, a comparison of the 26Al/10Be ratios in the WAIS Divide shallow core with those measured in the GISP2 ice core will demonstrate if this ratio can be used as an absolute chronometer of old Antarctic ice. The broader impacts of this project include the formation of a multi-disciplinary team of collaborators for the interpretation of future analyses of cosmogenic radionuclide data from the WAIS Divide ice core, the involvement and training of undergraduate and graduate students in the chemical processing of ice samples and interpretation of the cosmogenic nuclide data in the wider scope of climate change research, and explaining the importance of ice core and climate change studies to a wide range of lab visitors and students from local schools.

WELTEN/0636964奖奖支持了一个为期两年的项目，以使用加速器质谱法（AMS）在南极冰样中衡量宇宙基因核素，10BE，26AL和36CL的浓度。该项目是一项试点研究，用于将来对放射性核素的未来分析，该核素从WAIS的最多1000个单独的冰样品划分了深层冰芯。由于这些冰核研究涉及大量样品，并且及时分析了宇宙源性放射性核素的重要性，我们建议在普渡大学建立第二个化学分离线，与UC相同伯克利（Berkeley）的Siple Dome和GISP-2冰芯。在对12-16个测试冰样品进行彻底的实验室间比较之后，我们将使用两种提取线来测量来自WAIS分裂的浅冰芯中的宇宙基因核素。可以预期的是，使用两种化学分离线将使样品吞吐量增加两倍，并确保Purdue University在AMS上及时分析宇宙源性放射性核素。 该项目的智力优点在于，这些测量结果将使科学家能够将本地与全球影响分开。通过测量来自不同位置的冰芯中的几个放射线纤维化，可以消除绝对放射性核素浓度及其比率的变化是否归因于局部影响，例如大气循环，沉积机制和积雪速率的变化；还是它们是否是由于太阳活性和地磁场强的变化所致，主要过程影响了大气中宇宙核素的全球生产速率。最后，将WAIS划分的26AL/10BE比率与GISP2冰芯中测得的比率进行比较，将证明该比率是否可以用作旧南极冰的绝对天文计。 该项目的更广泛的影响包括组成了一个多学科的合作者团队，以解释来自WAIS Divide Ice Core的宇宙源性放射性核素数据的未来分析，本科生和研究生的参与和培训并解释了气候变化研究范围更广泛的宇宙核素数据，并解释了冰核和气候变化研究对来自当地学校的各种实验室访问者和学生的重要性。