Atmospheric Dust in North Central Greenland Ice: North Grip

本提案为参与格陵兰中北部的North GRIP或NGRIP （North Greenland Icesheet Project）深核项目。这项工作由丹麦人领导，其他六个国家的科学家也参与其中。如果获得资助，美国的贡献将用于测量粉尘的矿物学和放射性同位素特征，以确定其来源（本提案），并用于测量和解释稳定同位素（James White， U. Colorado）。按照丹麦人的说法，钻这个岩心的主要目的是为了从格陵兰岛的冰中恢复埃米恩人的可靠记录。然而，除了这项任务之外，还有很多东西要学，而且无论是否成功地恢复了未受干扰的埃米亚剖面，都可以从这个岩心中获得很多东西。该项目的目标是：-利用矿物学和Sr-， Nd-和pb同位素组成，确定冰芯记录的时期内沉积在NGRIP的大气尘埃的来源区域-希望包括Eemian -从而为古大气环流和从尘埃来源区域到格陵兰NGRIP部分的运输模式提供约束。-将NGRIP记录的这些尘源区域与同期在Summit （GISP2， GRIP）和其他可能的格陵兰岛核心地点（例如Dye 3）记录的尘源区域进行比较，从而开始辨别当地（格陵兰岛）运输路径的变化程度，进一步限制环流模式；-如果在NGRIP恢复了未受干扰的Eemian冰，具体比较该冰的尘埃与GRIP假定的Eemian冰的任何显著变化。

This proposal is to participate in the North GRIP or NGRIP (North Greenland Icesheet Project) deep-core project in North Central Greenland. This effort is begin led by the Danes with participation from scientists from about six other nations. If funded, the U.S. contribution will be in measurements of mineralogical and radiogenic-isotope characteristics of dusts to determine their provenance (this proposal), and in measuring and interpreting stable isotopes (James White, U. Colorado). The principal purpose in drilling this core, as stated by the Danes, was to recover a reliable record of the Eemian from Greenland ice. There is much to be learned beyond this task, however, and much to be gained from this core regardless of the success in recovering an undisturbed Eemian section. This project objectives are: - using mineralogical and Sr-, Nd- and Pb-isotope compositions, to determine the source areas of the atmospheric dusts that have been deposited at NGRIP over the period recorded by the ice core -- hopefully including the Eemian -- thus providing constraints for models of paleoatmospheric circulation and transport from the dust source areas to the NGRIP part of Greenland. - to compare these dust source areas recorded at NGRIP to those recorded at the same times in the dusts at Summit (GISP2, GRIP), and other possible Greenland core sites (e.g., Dye 3), and thus begin to discern degrees of local (Greenland) variability in transport pathways, further constraining circulation models; - if undisturbed Eemian ice is recovered at NGRIP, to specifically compare dusts from that ice to the putative Eemian ice, with any significant variations, at GRIP.