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FOREnSic Innovations to constrain GreenHouse Trace gas budgets

FOREnSic 创新限制 GreenHouse Trace 气体预算

基本信息

批准号：
NE/I021918/1
负责人：
Johannes Laube
金额：
$ 58.98万
依托单位：
University of East Anglia
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI021918%2F1
关键词：
FOREnSic Innovations constrain GreenHouse Trace

项目摘要

A halocarbon is an organic molecule containing at least one halogen atom, i.e. fluorine, chlorine, bromine or iodine. Halocarbons can be found almost everywhere: in refrigerators, in TVs, in fire extinguishers, in plants and - in small traces - in air. Usually there is less than one molecule of halocarbons in a billion air molecules. But despite these low abundances halocarbons both act as powerful greenhouse gases and are potent depleters of stratospheric ozone. They presently account for more than 20% of the anthropogenic greenhouse effect, and this fraction could potentially increase in the future. The aim of this project is to explore the capabilities of a number of highly innovative analytical tools to enhance the present level of understanding of important halocarbons and their origins, distributions and fate in the atmosphere in the past, present and future. Firstly, the isotope ratios of halogens in halocarbon gases will be used as a wholly novel tool to identify and quantify the sources and sinks of very persistent compounds such as the chlorofluorocarbons (CFCs). CFCs have been banned in most countries. But because they break down so slowly, it will take at least many decades before they disappear from the atmosphere. A very important question is, how long? One part of the answer could lie in the stratosphere, which is the only place where CFCs do break down. I am investigating the isotopes of halogens in CFCs and these contain information about the exact manner and speed of their stratospheric breakdown. The second part of the answer relies on how much CFC is still being released to the atmosphere (e.g. from old cars, landfills or illegal use). To distinguish in the atmosphere between CFC released years ago and CFC released now, one could again benefit from isotopic information. This is because the different molecules contain an isotopic 'fingerprint' which is often characteristic for the manufacturing process and also changes over time in the atmosphere. Consequently, the aim is to detect as many 'fingerprints' as possible and to identify and quantify the remaining emissions. Secondly, pioneering work on the detection of the rapidly growing number of industrial halocarbon compounds in the atmosphere will be continued and extended. There is an emerging threat from halocarbons with respect to global warming. The replacement compounds for CFCs are increasing rapidly in the atmosphere, and many of them are strong greenhouse gases. The variety of compounds used in industrial processes is increasing so fast, that scientists are struggling to keep up. Within this project new techniques to scan the atmosphere and track down these 'novel' halocarbons will be investigated. Consequently the threat posed by these compounds both to climate and to stratospheric ozone will be estimated. Finally, the promising methodologies of adapting two-dimensional gas chromatography and time-of-flight mass spectrometry for atmospheric trace gas studies will be explored and will build upon the outcomes of the first two activities. This project will contribute to improved predictions of the recovery of the ozone layer and serve as an early-warning system for emerging threats from halocarbons in the atmosphere. Society will benefit from all of these activities as it will help to predict, when the ozone layer - and thus the protection from skin-cancer-causing UV radiation - will fully recover. Moreover, this project will help to better understand the risks arising from halocarbons with regard to climate change. It will also develop innovative new tools with which to study the chemistry of the atmosphere.

卤化碳是含有至少一个卤素原子，即氟、氯、溴或碘的有机分子。卤代烃几乎随处可见：冰箱、电视、灭火器、植物以及空气中（微量）。通常十亿个空气分子中只有不到一个卤化碳分子。但尽管丰度较低，卤化碳仍是强大的温室气体，也是平流层臭氧的有力消耗者。它们目前占人为温室效应的 20% 以上，并且这一比例未来可能会增加。该项目的目的是探索一些高度创新的分析工具的能力，以提高目前对重要卤代碳及其过去、现在和未来在大气中的起源、分布和归宿的理解水平。首先，卤化碳气体中卤素的同位素比将用作一种全新的工具，用于识别和量化非常持久的化合物（例如氯氟烃（CFC））的源和汇。大多数国家已禁止使用 CFC。但由于它们分解得非常缓慢，因此至少需要几十年的时间才能从大气中消失。一个非常重要的问题是，需要多长时间？答案之一可能在于平流层，这是氟氯化碳唯一能分解的地方。我正在研究氟氯化碳中的卤素同位素，其中包含有关其平流层分解的确切方式和速度的信息。答案的第二部分取决于仍有多少氟氯化碳被释放到大气中（例如来自旧车、垃圾填埋场或非法使用）。为了在大气中区分几年前释放的 CFC 和现在释放的 CFC，人们可以再次从同位素信息中受益。这是因为不同的分子含有同位素“指纹”，该同位素“指纹”通常是制造过程的特征，并且也会随着大气中的时间而变化。因此，我们的目标是检测尽可能多的“指纹”，并识别和量化剩余的排放量。其次，将继续并扩大对大气中数量迅速增长的工业卤化碳化合物进行检测的开拓性工作。卤化碳对全球变暖构成了新的威胁。大气中氟氯化碳的替代化合物正在迅速增加，其中许多是强温室气体。工业过程中使用的化合物种类增长如此之快，科学家们正在努力跟上。在该项目中，将研究扫描大气并追踪这些“新型”卤化碳的新技术。因此，将估计这些化合物对气候和平流层臭氧造成的威胁。最后，将探索采用二维气相色谱法和飞行时间质谱法进行大气痕量气体研究的有前途的方法，并将以前两项活动的成果为基础。该项目将有助于改进对臭氧层恢复的预测，并作为大气中卤化碳新威胁的预警系统。社会将从所有这些活动中受益，因为它将有助于预测臭氧层何时能够完全恢复，从而防止引起皮肤癌的紫外线辐射。此外，该项目将有助于更好地了解卤化碳对气候变化造成的风险。它还将开发创新的新工具来研究大气化学。