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.

陆地植物是大气中挥发性有机化合物的最大排放者。这些化合物在运输到极地地区的过程中会发生化学变化。确定冰芯中的转变产物可以提供有关过去大气如何对突然的气候变化做出反应的信息，类似于当前的变化，从而有助于了解全球不确定性。由于冰芯中的有机化合物浓度低且样品可用性有限，分析冰芯中的有机化合物是一项分析挑战。在这个项目中，我们的目标是将质谱分析能力推向极限，首次对逐渐融化的冰芯进行连续流动分析，以测定档案中高时间分辨率的有机化合物。这种新颖的方法一旦投入使用，可以应用于一系列冰芯，但对于较旧的冰芯尤其有用，因为更深部分的紧凑分层，可以检索使用传统方法可能会丢失的古气候信息。鉴于目标分析物在运输到极地期间在大气中发生转化，将开发一个结合反应性和全球运输的理论模型，以推断目标分析物在其大气寿命期间与其发生反应的大气氧化剂的平均浓度。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验证理论框架。