Atmospheric Transport and Deposition of Chemical Constituents at Summit, Greenland: Interpretation of the GISP-2 Ice Core

该项目是对化学痕量元素和物种从来源区域通过大气向格陵兰冰盖输送的调查的继续。其目标是为解释通过格陵兰冰盖计划钻探工作获得的长冰芯中的微量元素分布提供信息。冰芯将提供跨越20万年的详细记录。该项目有三个具体目标：(1)确定到达钻探地点的化学成分的来源区域和大气路径，包括在运输过程中气团特征可能发生的变化；(2)量化大气中的化学物质与冰盖中的化学物质之间的关系；(3)利用这些信息解释深层冰芯数据。之前的野外工作已经收集了空气、气溶胶、降水和积雪的样本，这些样本将被分析各种阴离子和阳离子、微量元素、碳化合物和微量气体。本项目将重点研究沉积机制。第一个目标将通过测量空气和雪中化学物质的浓度来实现，然后将这些信息与其他研究人员的气象数据结合起来。主要阴离子和阳离子的浓度将在我们的实验室通过离子色谱法测定，而微量元素和其他物种的浓度将通过与其他小组的合作来获得。第二个目标包括测量湿的、干的和雾的沉积，以及化学物质沉积后积雪中发生的变化。第三个目标将通过与正在积极处理核心数据的GISP2研究人员合作，开发模型来解释影响现场空气和雪化学的过程，从而实现第三个目标。结果将更好地解释冰芯数据，并减少使用岩芯数据确定过去大气条件所涉及的不确定性。***

This project is the continuation of an investigation of the transport of chemical trace elements and species from source regions through the atmosphere to the Greenland ice sheet. Its goal is to provide information for the interpretation of the trace element distribution in the long ice core that has been obtained through the Greenland Ice Sheet Program (GISP- 2) drilling effort. The ice core will provide a detailed record spanning 200,000 years. The project has three specific objectives: (1) the identification of source regions and atmospheric pathways for the chemical constituents reaching the drill site, including the possible changes in air mass characteristics during transit, (2) the quantification of relationships between chemical species in the atmosphere and those in the ice sheet, and (3) the interpretation of the deep ice core data using this information. Prior field work has resulted in the collecting of samples of air, aerosol, precipitation, and deposited snow, which will be analyzed for various anions and cations, trace elements, carbon compounds, and trace gases. This project will emphasize the deposition mechanisms. The first objective will be achieved by measuring concentrations of chemical species in air and snow, and then combining this information with meteorological data of other investigators. Concentrations of major anions and cations will be determined by ion chromatography in our laboratories, while concentrations of trace elements and other species will be obtained by collaboration with other groups. The second objective involves measurement of wet, dry, and fog deposition, as well as changes that occur in the snow pack after deposition of chemical species. The third objective will be achieved by developing models to explain the processes influencing air and snow chemistry at the site in collaboration with GISP-2 researchers who are actively working with the core data. The results will be a better interpretation of the ice c ore data, and the reduction of uncertainties involved in using the core data to determine past atmospheric conditions. ***