Testing amino acid paleothermometry in radiocarbon-dated lake sediment

在放射性碳测年的湖泊沉积物中测试氨基酸古测温法气候变化给社会带来了重大挑战。需要更多的信息，以便将最近的气候变化置于自然气候变异性的长期背景下。这些信息有助于预见未来可能出现的气候趋势，特别是那些涉及气候系统缓慢变化特征的气候系统，这些气候系统将在未来数百年至数千年内继续演变。各种地质证据可以用来延长对温度和其他气候变量的观测时间。该项目致力于开发一种新的方法，利用湖泊沉积物中含有的氨基酸来估计数千年前的温度变化。这些分子被降解的程度在很大程度上取决于它们储存的环境温度和自它们形成以来的时间长度。该项目将利用实验室实验来确定不同降解反应的温度敏感性，并结合放射性碳测年来确定周围湖泊沉积物的年龄。资金还将用于维持北亚利桑那大学氨基酸地质年代学实验室的共享使用，这是美国唯一的同类实验室。该项目还将为本科生和研究生在STEM工作中的职业生涯做好准备。开发新的方法来量化过去的温度是气候科学的高度优先事项。地质环境中氨基酸(AAs)的化学变化程度主要由分子形成以来经过的时间长度和周围沉积后的温度决定。再加上通过放射性碳(14C)测年进行的独立年龄控制，涉及AAs的化学反应可以用来量化过去温度变化的时间和幅度。AAS在湖泊沉积物中含量丰富，一般在湖泊中连续积累了数千年，因此可以从广泛分布的地点对其进行详细的时间序列分析。该项目将在14C测年和实验室加热的湖泊沉积物上生成第一个主要的AA数据集。该项目建立在越来越多的湖泊沉积物中AAs研究的基础上，并利用了NSF支持的湖泊核心社区资源。这项奖励将维持氨基酸地质年代学实验室作为研究基础设施，使其能够继续其培训用户、提供试验性研究分析以及协助数据解释和整理的长期传统。该项目还将支持STEM研究生和本科生。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Testing amino acid paleothermometry in radiocarbon-dated lake sedimentClimate change poses a major challenge for society. More information is needed to put recent climate changes into a long-term context of natural climate variability. This information helps to foresee possible future climate trends, especially those that involve slow-moving features of the climate system, which will continue to evolve over hundreds to thousands of years to come. A variety of geological evidence can be used to extend observations of temperature and other climate variables back in time. This project focuses on developing a new method of estimating temperature changes extending back thousands of years by using amino acids contained in lake sediment. The extent to which these molecules have been degraded depends largely on the temperature of the environment in which they have been stored and the length of time since they were formed. This project will use laboratory experiments to determine the temperature sensitivity of different degradation reactions coupled with radiocarbon dating to determine the age of the enclosing lake sediment. Funding will also be used to sustain the shared use of the Amino Acid Geochronology Laboratory at Northern Arizona University, which is the only one of its type in the United States. The project will also prepare undergraduate and graduate students for careers in the STEM workforce.Developing new methods to quantify past temperature is a high priority for climate science. The extent to which amino acids (AAs) in geologic settings have been chemically altered is primarily determined by the length of time elapsed since the molecules formed and by the ambient post-depositional temperature. Coupled with independent age control though radiocarbon (14C) dating, chemical reactions involving AAs can been used to quantify the timing and magnitude of past temperature changes. AAs are abundant in lake sediment, which has generally accumulated continuously in lakes over thousands of years, and thereby can be analyzed in detailed time series from widely distributed sites. This project will generate the first major AA dataset on 14C-dated and laboratory heated lake sediment. This project builds on a growing number of studies of AAs in lake sediment and it takes advantage of NSF-supported lake-core community resources. This award will sustain the Amino Acid Geochronology Laboratory as research infrastructure, enabling it to continue its long tradition of training users, offering pilot-study analyses, and assisting with data interpretation and curation. This project will also support STEM graduate and undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.