Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core

合作研究：南极西部冰盖分裂冰芯硝酸盐和硫酸盐的多同位素分析

• 批准号: 0538049
• 负责人: Eric Steig
• 金额: $ 30.95万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0538049&HistoricalAwards=false
• 关键词: Collaborative; Research; Multiple; isotope; Analysis

0538049SteigThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.

0538049Steig 该奖项支持一个项目，该项目旨在开发涵盖过去约 10 万年的硝酸盐和硫酸盐多种同位素比率的第一个完整记录，记录来自计划用于西南极冰盖 (WAIS) 中央冰分水岭的深冰芯。 WAIS Divide 冰芯将是从南极洲获得的最高分辨率的长冰芯，我们预计可以获得重要的补充信息，包括对过去积累率、温度以及 H2O2、CO 和 CH4 等化合物的准确了解。这些化合物在全球大气化学和气候中发挥着重要作用。 尤其巨大的潜力在于使用多种同位素特征。由于其前体与臭氧的相互作用，在硝酸盐和硫酸盐中都观察到了臭氧独特的质量独立分馏 (MIF) 17O 特征。 测量硫酸盐和硝酸盐小样本的多同位素组成的方法的开发使得对冰芯的连续高分辨率测量首次成为可能。最近的工作表明，此类测量可用于确定古大气中的羟基自由基（OH）和臭氧（O3）浓度以及分配硫酸盐和硝酸盐来源。 使用这些同位素测量来量化沉积后的变化也具有相当大的潜力。 在头两年中，将获得 WAIS 分水岭上部约 100 米冰层的连续测量结果，以详细了解季节到百年尺度的变化。第三年，将在整个深核可用深度（预计此时达到约 500 m）进行测量。 该项目更广泛的影响包括在大气化学、冰川学、气象学和古气候学等不同领域的应用。由于硝酸盐和硫酸盐是重要的大气污染物，因此研究结果也将与全球环境政策直接相关。 该项目将与国际极地年（2007-2008）同时举行，并有助于实现IPY的目标，其中包括促进跨学科研究，以加深对极地地区大气化学和气候的了解。