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

知识价值：地下水系统中的惰性气体可以通过估算惰性气体温度来指示无冰地区过去的气候。传统的惰性气体温度不能在水不与大气接触的冰雪覆盖地区得到。这项工作的目标是利用冰/水界面冰覆盖湖泊的稀有气体特性来开发一种新的古气候代理，该代理具有在极地和高山冰川地区常规使用的潜力。泰勒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，这两者都受气候变化的影响。湖泊的常年冰覆盖在水/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代理的理想场所。拟议的研究包括对湖水、溪水、冰盖和冰川冰进行广泛的惰性气体取样活动。该数据集以及在该地区持续收集的数据将为开发、测试和完善数学模型提供坚实的基础，这些模型能够准确描述重惰性气体浓度分布以及湖泊中随时间推移的总体库存。这些将提供关于主要气候事件发生的信息，同时提供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在密歇根大学创建的针对非科学专业的新课程中。每年将为1-2名本科生提供研究机会，并将资助一名博士生。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.