A New Analytical-Theoretical Method to Assess Past Changes in the Oxidising Capacity of Atmospheres

评估大气氧化能力过去变化的新分析理论方法

基本信息

批准号：
2459153
负责人：
金额：
--
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2459153
关键词：
New Analytical Theoretical Method Assess

项目摘要

Terrestrial plants are the largest emitter of volatile organic compounds in the atmosphere. These compounds undergo chemical transformations during their transport to polar regions. Determining the transformation products in ice cores could provide information on how the past atmosphere reacted to abrupt climate changes, analogous to the present changes, thus contributing to knowledge around global uncertainties. Analysing organic compounds in ice cores represents an analytical challenge due to their low concentrations and limited sample availability. In this project, we aim at pushing mass spectrometry capability to its limits to allow, for the first time, for a continuous flow analysis of ice cores, gradually melted in continuous, for the determination of organic compounds with high time resolution in the archive. This novel method, once operational, can be applied to a range of ice cores but is especially useful for older ice cores, given the compact stratification of deeper segments, to retrieve paleoclimatic information that would otherwise be lost using traditional methods. Given that the target analytes are being transformed in the atmosphere during their transport to polar regions, a theoretical model, combining reactivity and global transport, will be developed to infer average concentrations of the atmospheric oxidants with which the target analytes have reacted during their atmospheric lifetime. Validation of the theoretical framework will be done by comparing model results of oxidant concentrations with direct measurements available for recent years.

陆生植物是大气中挥发性有机化合物的最大发射极。这些化合物在运输到极性区域期间经历了化学转化。确定冰芯中的转化产物可以提供有关过去大气对突然气候变化的反应的信息，这与当前的变化相似，从而促进了围绕全球不确定性的知识。分析冰芯中的有机化合物代表了由于其低浓度和样品可用性有限而导致的分析挑战。在这个项目中，我们旨在将质谱能力推向其限制，以便首次允许对冰芯进行连续的流量分析，并逐渐融化，以确定档案中具有较高时间分辨率的有机化合物。这种新颖的方法一旦运行，就可以应用于一系列冰芯，但考虑到更深的细分市场的紧凑分层，对于较旧的冰芯特别有用，以检索使用传统方法丢失的古气候信息。鉴于目标分析物在向极性区域的运输过程中正在大气中转化，因此将开发一个理论模型，结合反应性和全球运输，以推断目标分析物在大气生命中反应的大气氧化剂的平均浓度。理论框架的验证将通过将氧化剂浓度的模型结果与近年来可用的直接测量结果进行比较来完成。