Collaborative Research: An Isotope MIF Study of Volcanic Events in Greenland Ice Cores

合作研究：格陵兰冰芯火山事件的同位素 MIF 研究

• 批准号: 0612461
• 负责人: Jihong Cole-Dai
• 金额: --
• 依托单位: South Dakota State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0612461&HistoricalAwards=false
• 关键词: Collaborative; Research; Isotope; MIF; Study

ABSTRACTCole-DaiOPP-0612451ThiemensOPP-0612422This collaborative study between South Dakota State University and Universityof California, San Diego will investigate mechanisms of atmospheric oxidationchemistry using sulfur dioxide from volcanic eruptions. The Principal Investigators will: 1) obtain several shallow ice cores from central Greenland; 2) extract sulfate from a number of known large volcanic eruptions in the last 600 years; 3) measure the mass independent fractionation (MIF) of sulfur and oxygen isotopes in the volcanic sulfate; 4) test hypotheses of sulfur dioxide oxidation by active oxidation intermediates and by photochemistry; and 5) investigate the quantitative impact of atmospheric variables on ice core volcanic signals. The goals are to: 1) better understand the chemical processes of atmospheric oxidation and the effect of atmospheric dynamics on ice core volcanic signals, and 2) to establish a new mechanism to track the sensitivity of the atmosphere to environmental disturbance and hence, is of importance to anthropogenic impact models.Intellectual Merit: Oxidation is one of the basic chemical transformation processes in the atmosphere. It plays a critically important role in global biogeochemical cycles and in the removal of many pollutant chemicals from the atmosphere. Introduction of large amounts of chemical substances, from either natural or anthropogenic sources, can alter the atmosphere's oxidative abilities and affect the quality and functions of the atmospheric environment. Very limited knowledge of the mechanisms of atmospheric oxidation, particularly in the stratosphere, hampers the efforts to construct robust models to predict anthropogenic impact on the atmospheric environment. The Principal Investigators recently discovered that MIF isotopic signatures of volcanic sulfate extracted from Antarctica ice cores contain new and valuable information on atmospheric oxidation that is unavailable by other means. Limited data have attracted attention from atmospheric modelers with proposals of alternative photochemical and/or oxidation processes. More isotopic MIF data are needed both to test and to encourage new hypotheses spurred by preliminary results. In an on-going project, they added to the MIF dataset with measurements on volcanic sulfate from South Pole ice cores. This project will produce first volcanic sulfate MIF data from Northern Hemisphere ice cores. They will use the bi-polar volcanic sulfate MIF dataset to: 1) determine the global homogeneity of stratospheric oxidation chemistry, 2) test the hypothesis of stratospheric SO3 photolysis, 3) determine the stratospheric or tropospheric nature and degree of two climatologically important large volcanic eruptions; and 4) establish and verify a quantitative MIF-mass loading relationship that can be used to estimate aerosol impact of past volcanic eruptions from their ice core sulfate signals.Broader Impacts: Achieving the goals of the research will help advance the frontiers of environmental science, particularly in the areas of climate change and human impact. By providing educational and research opportunities to SDSU and UCSD students, the project will promote the integration of research with education and contribute to human resource development in science and engineering. The project will contribute to a current REU chemistry site program at SDSU.

这项由南达科他州州立大学和加州大学圣地亚哥分校合作进行的研究将利用火山喷发产生的二氧化硫来研究大气氧化化学的机制。主要研究者将：1）从格陵兰岛中部获得几个浅冰芯; 2）从过去600年的一些已知的大型火山喷发中提取硫酸盐; 3）测量火山硫酸盐中硫和氧同位素的质量无关分馏（MIF）; 4）检验二氧化硫通过活性氧化中间体和光化学氧化的假设;（5）研究大气变量对冰芯火山信号的定量影响。目标是：1）更好地理解大气氧化的化学过程和大气动力学对冰芯火山信号的影响; 2）建立一种新的机制来跟踪大气对环境扰动的敏感性，从而对人类影响模式具有重要意义。它在全球地球化学循环和从大气中清除许多污染化学品方面发挥着至关重要的作用。从自然或人为来源引入大量化学物质可改变大气的氧化能力，影响大气环境的质量和功能。由于对大气氧化机制，特别是平流层氧化机制的了解非常有限，因此无法建立可靠的模型来预测人类活动对大气环境的影响。主要研究人员最近发现，从南极洲冰芯中提取的火山硫酸盐的MIF同位素特征包含了关于大气氧化的新的和有价值的信息，这些信息是通过其他手段无法获得的。有限的数据引起了大气建模者的注意，并提出了替代光化学和/或氧化过程的建议。需要更多的同位素MIF数据来测试和鼓励由初步结果激发的新假设。在一个正在进行的项目中，他们在MIF数据集上增加了对南极冰芯火山硫酸盐的测量。该项目将从北方冰芯中产生第一批火山硫酸盐MIF数据。 他们将使用双极火山硫酸盐MIF数据集：1）确定平流层氧化化学的全球均匀性，2）测试平流层SO 3光解的假设，3）确定两次气候上重要的大型火山爆发的平流层或对流层性质和程度;以及4）建立和验证定量的MIF-质量负荷关系，该关系可用于根据冰芯硫酸盐信号估计过去火山爆发的气溶胶影响。实现研究目标将有助于推进环境科学的前沿，特别是在气候变化和人类影响领域。通过为SDSU和UCSD学生提供教育和研究机会，该项目将促进研究与教育的融合，并为科学和工程领域的人力资源开发做出贡献。该项目将有助于目前在SDSU REU化学网站程序。