Collaborative Research: Ice Core Studies Reconstructing Greenland Climate During the Eemian and Beyond

这三个机构之间的合作项目的主要目标是了解格陵兰冰盖在Eemian时期（大约130，000至115，000年前，地球历史上最后一个主要的间冰期）的范围和演变以及紧接在此之前的冰川消退（“终止2”）。地理信息系统是在多个时间尺度上影响海平面、北极和全球气候的重要因素。它的动态需要在过去的气候变化的背景下进行理解，但由于缺乏123，000年前的连续冰芯记录，因此在最后一个冰河时代之前，关于地理信息系统的足迹，体积和海拔的信息很少。在Eemian期间，GIS的大小可能是现在的一半，导致海平面“过度”上升约3米。描述冰川终止2和Eemian期间GIS的演变将提高我们对其动态的理解，并提高我们预测未来几个世纪海平面上升的能力。在以前钻取的冰芯底部确实存在较老的冰，但从这些较老的冰中提取年龄和气候信息的工作受到阻碍，因为它在地层上受到干扰，而且在许多情况下受到土壤或基岩物质的污染。这些研究人员提出了几种新的方法来确定这些受干扰和/或“脏”冰的日期，并提取有关气候和冰盖范围的信息。调查人员将结合联合收割机的新测量结果和其他可用数据，以制定终止2和Eemian期间GIS的更完整历史。他们将与冰盖建模人员合作，研究Eemian数据为模型提供的约束条件，并提高其预测能力。这些努力有可能提高我们预测未来几十年至几个世纪地理信息系统对海平面上升的贡献的能力。教育和推广活动包括培训两名研究生，将这项研究纳入暑期教师充实计划，为研究生和博士后举办系列讲座，并通过新闻媒体传播研究结果。

The primary goal of this collaborative project between three institutions is to understand the extent and evolution of the Greenland Ice Sheet (GIS) during the Eemian period (roughly 130,000 to 115,000 years ago, the last major interglacial period in Earth's history) and the deglaciation immediately preceding it ("Termination 2"). The GIS is an important agent influencing sea level, and Arctic and global climate, on multiple timescales. Its dynamics need to be understood in the context of past climate changes, but there is little information available about the footprint, volume, and elevation of the GIS prior to the last ice age due to the absence of continuous ice core records prior to 123,000 years ago. During the Eemian, the GIS was perhaps half its present size, contributing on the order of 3 m to "excess" sea level rise. Characterizing the evolution of the GIS during glacial termination 2 and the Eemian would improve our understanding of its dynamics, and enhance our ability to make projections of sea level rise during the coming centuries. Older ice does exist at the bottoms of previously drilled ice cores, but the extraction of age and climate information from this older ice is hampered by the fact that it is stratigraphically disturbed and, in many cases, contaminated with soil or bedrock material. These investigators propose several novel methods to date this disturbed and/or "dirty" ice and to extract information on climate and ice sheet extent. The investigators will combine their new measurements and other available data to develop a more complete history of the GIS during termination 2 and the Eemian. They will work with ice sheet modelers to investigate the constraints that the Eemian data provide for the models and improve their predictive capability. These efforts have the potential to improve our ability to predict the contribution of the GIS to sea-level rise in the coming decades to centuries. Educational and outreach activities include the training of two graduate students, inclusion of this research in summer teacher enrichment programs, a lecture series for graduate students and postdocs, and communication of the results through the news media.