Record of the 17O-excess of H2O in the WAIS Ice Core

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该奖项支持了一个项目，该项目从目前正在南极洲西部钻探的WAIS Divide冰芯中获得约10万年的17o -过量记录。迄今为止，仅在一个冰芯上获得了17o的过量记录。从现象。WAIS Divide之所以与Vostok进行比较，是因为它位于一个非常不同的水汽输送体系中，并且将受到海冰和大气环流可能完全不同的变化的影响。这项工作的智力价值在于，通过对冰芯H2O中的18O/16O和17O/16O的高精度测量获得的17O-excess提供了与氘-excess高度互补的信息，氘-excess用于提供对过去气候条件的有用见解，因为它依赖于极地降水最终产生的海洋表面源区的蒸发条件。与氘过量不同，17o过量不受源温度的影响，在从源到冰盖的运输过程中只受分馏的微弱影响。因此，17O-excess与传统测量相结合，作为评估过去气候条件的有力新工具具有巨大潜力。特别是，它提供了解开源湿度、风速和温度、当地站点温度和运输过程中的分馏对冰芯水同位素记录的影响的机会。这项工作的更广泛的影响是，它有助于发展冰川学和古气候学以及其他研究领域所需的基础设施和专业知识。研究生将在方法开发和冰芯剖面分析和解释两方面工作，为一篇全面而新颖的博士论文提供充足的材料。

Steig/0837990This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This award supports a project to obtain a ~100,000-year record of 17O-excess from the WAIS Divide ice core, currently being drilled in West Antarctica. To date, a 17O-excess record has been obtained only on one ice core ? from Vostok. WAIS Divide is appealing for comparison with Vostok because it is located in a very different moisture transport regime, and will be influenced by potentially quite different changes in sea ice and atmospheric circulation. The intellectual merit of the work is that 17O-excess, obtained from the high-precision measurement of both 18O/16O and 17O/16O in ice core H2O, provides information highly complementary to deuterium excess which is used to provide useful insight into past climate conditions because of its dependence on evaporative conditions at the ocean surface source regions where polar precipitation is ultimately derived. Unlike deuterium excess, 17O-excess is independent of source temperature, and is only weakly influenced by fractionation during transport from source to ice sheet. 17O-excess therefore offers great potential, in combination with traditional measurements, as a powerful new tool for evaluating climate conditions in the past. In particular, it provides the opportunity to disentangle the effects of source humidity, wind speed, and temperature, local site temperature and fractionation during transport, on ice core water isotope records. The broader impacts of the work are that it contributes to the development of infrastructure and expertise needed both for glaciology and paleoclimatology, as well as for other research areas. A graduate student will work on both the method development and the analysis and interpretation of the ice core profile, providing plenty of material for a well-rounded and novel Ph.D. thesis.