Understanding the loss of atmospheric chlorine atoms
Lead Research Organisation:
University of York
Department Name: Chemistry
Abstract
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.
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.
Organisations
People |
ORCID iD |
| Terry Dillon (Primary Supervisor) | |
| Jordan Stewart (Student) |