Understanding the loss of atmospheric chlorine atoms

该项目将建造第一台能够测量大气中氯原子损失率的仪器，并将其部署在实地，以促进我们对氯在控制空气质量和气候方面的重要性的认识。对流层氧化剂负责降解排放到大气中的污染物，因此决定地球系统的过程，包括：气候气体(如甲烷)的寿命；影响空气质量的二次污染物(如臭氧和颗粒)的产生；以及化学物质向生态系统的沉积。氯原子是这些大气氧化剂中最不被了解的，目前对它们的作用的估计相差3个数量级。我们对大气化学知识的缺失是由于缺乏测量结果。在这个项目中，你将开发和部署一种新的现场仪器，帮助解决这一问题，进而有助于减少全球空气质量和气候模型中的不确定性。为了准确地表示大气中的氯化学，我们需要了解氯原子是如何产生和丢失的。这个PHD项目最初的重点将是开发一种新的仪器，直接测量大气中氯原子的损失率。测量大气氧化剂损失率的仪器。例如OH，以前是由爱德华兹博士和其他人开发的，并在确定我们对大气化学理解中的其他重大不确定性方面产生了影响。沃尔夫森大气化学实验室(WACL)特里·狄龙博士的化学动力学小组最近与约克等离子体研究所的蒂莫·甘斯教授合作，开发了一种基于实验室的测量氧化剂损失率的技术。学生们将与狄龙博士密切合作，将这种实验室方法转化为可在真实大气中使用的方法。为了直接测试我们对真实大气中氯原子反应路径的理解，接下来将在清洁和城市环境中进行现场测量。清洁的环境将在热带大西洋(https://www.ncas.ac.uk/en/our-data/255-amf-main-category/cvao/1070-cvao-overview).的佛得角岛屿上的Wacl天文台进行城市环境将位于伦敦最新的NERC空气污染超级区之一。这些观察将是对大气氧化化学研究的重大贡献，并将使化学模型模拟能够作为更广泛项目的一部分来挑战和探索氯对空气质量和气候都重要的过程的真正影响。

This project will build the first instrument capable of measuring the loss rate of chlorine atoms in the atmosphere and to deploy this in the field to advance our knowledge on the importance of chlorine in controlling air quality and climate.Tropospheric oxidants are responsible for the degradation of pollutants emitted into the atmosphere, and so determine Earth system processes including: the lifetime of climate gases such as methane; the production of secondary pollutants such as ozone and particles that impact on air quality; and the deposition of chemicals to ecosystems. Chlorine atoms (Cl) are the least understood of these atmospheric oxidants, with current estimates of their role ranging varying by 3 orders of magnitude. This failing in our knowledge of atmospheric chemistry is due to a lack of measurements. In this project you will develop and deploy a new field instrument that will help to address this problem and in turn help to reduce uncertainties in global air quality and climate models. In order to accurately represent atmospheric Cl chemistry we need to understand both how Cl atoms are produced and lost. The initial focus of this PhD project will be to develop a new instrument to directly measure the loss rate of Cl atoms in the atmosphere. Instruments to measure loss rates of the atmospheric oxidants. Such as OH, have previously been developed by Dr Edwards and others, and have been influential in identifying other significant uncertainties in our understanding of atmospheric chemistry. A laboratory based technique for measuring oxidant loss rates has recently been developed in Dr Terry Dillon's chemical kinetics group in the Wolfson Atmospheric Chemistry Laboratories (WACL), in collaboration with Prof Timo Gans in the York Plasma Institute. The studentship will work closely with Dr Dillon to transfer this laboratory method into one that can be deployed in the real atmosphere. In order to provide a direct test of our understanding of Cl atom reaction pathways in the real atmosphere, field measurements will then be made in both clean and urban environments. The clean environment will be at the WACL observatory on the islands of Cape Verde in the Tropical Atlantic (https://www.ncas.ac.uk/en/our-data/255-amf-main-category/cvao/1070-cvao-overview). The urban environment will be at one of the new NERC Air pollution supersites in London. These observations will represent a major contribution to the study of atmospheric oxidation chemistry, and will enable chemical model simulations to be run as part of the wider project to challenge and explore the true impact of Cl on processes important for both air quality and climate.