Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases

智力价值：地下水系统中的稀有气体可以通过估计稀有气体的温度来指示无冰区过去的气候。传统的惰性气体温度无法在冰盖地区得出，因为那里的水不与大气接触。拟议工作的目标是利用冰/水界面冰盖湖泊中的惰性气体特性，开发一种新的古气候指标，有可能在极地和高山冰川地区常规使用。泰勒河谷湖泊的演变与附近冰川的动态以及罗斯冰架的进退密切相关，这两者都是由气候变化决定的。这些湖泊的常年冰盖在水/冰界面形成，并在顶部升华，使这些湖泊成为测试和开发这种新替代品的理想选择。拟议的研究涉及对湖水、溪水、冰盖和冰川进行广泛的惰性气体采样活动。这一数据集，加上在该地区不断收集的数据，将为开发、测试和改进能够准确描述重惰性气体浓度分布及其随时间推移在湖泊中的总库存的数学模型提供坚实的基础。这些将提供有关重大气候事件发生情况的信息，同时提供对这些事件的时间限制。更广泛的影响：这项工作的发现将被插入到PI在密歇根大学为非理科专业学生创建的一个新班级中。它将为每年1-2名本科生创造研究机会，并将支持一名博士生。这项研究的结果可能具有很强的社会相关性。

Intellectual Merit: Noble gases in groundwater systems can indicate past climates in ice-free regions through estimation of noble gas temperatures. Traditional noble gas temperatures cannot be derived in ice-covered regions where water is not in contact with the atmosphere. The goal of the proposed work is to take advantage of noble gas properties in ice covered lakes at the ice/water interface to develop a new paleoclimate proxy with the potential to be routinely used in both polar and alpine glacial regions. The evolution of the Taylor Valley lakes is intimately connected to the dynamics of nearby glaciers, as well as the advance and retreat of the Ross Ice Shelf, both of which are dictated by climate change. The perennial ice cover of the lakes form at the water/ice interface and sublimate at the top rendering these lakes ideal to test and develop this new proxy. The proposed research involves conducting an extensive noble gas sampling campaign of lake water, stream water, ice covers and glacial ice. This data set, together with data continuously collected in the area will provide a solid basis to develop, test and refine mathematical models capable of accurately describing heavy noble gas concentration profiles as well as their overall inventory in the lakes over time. These will provide information on the occurrence of major climatic events while simultaneously providing temporal constraints on such events. Broader impacts: The findings of this work will be inserted into a new class that the PI has created at the University of Michigan targeted at non-science majors. It will create research opportunities for 1-2 undergraduates each year and will support a PhD student. The outcomes of this research could have strong societal relevance.