14CO for assessing regional CO emissions and tracking the oxidative capacity of the atmosphere
Author(s)
Blyth, Liam
Type
Thesis
Abstract
Understanding both regional and global carbon cycles is critical for managing urban pollution and mitigating climate change. Radiocarbon in atmospheric carbon monoxide (14CO), primarily produced in the upper atmosphere via cosmic rays, is a valuable but underutilised tracer of regional carbon monoxide (CO) sources and the oxidative capacity of the atmosphere.
This thesis develops novel techniques to utilise 14CO to trace regional CO emissions and global oxidative capacity. Combining regional emissions with an atmospheric dispersion model, we use 14CO to understand CO sources on a regional scale. By 14CO production schemes into a largescale atmospheric model, we investigate its capacity as a tracer species for the hydroxyl radical (OH).
Our regional simulations demonstrate that 14CO can distinguish different CO emissions estimates in the UK and EU. Different emissions schemes show distinct Δ14CO-CO relationships indicating different fuel sources. We outline a measurement campaign that could be used to corroborate the results of our simulation study. Additionally, we provide the measured values necessary to conduct a similar study worldwide.
Our global study incorporated the latest cosmogenic 14CO production model into a global atmospheric model to carry out the first multi-decadal simulations to fully evaluate its capacity to trace the hydroxyl radical (OH). We also integrate secondary production of 14CO into an atmospheric model for the first time, investigating the role they play in surface concentrations.
Our results confirm the utility of 14CO as a tracer on a variety of spatial and temporal scales. This thesis deepens our understanding of 14CO as a tool in atmospheric science, offering unique insights into regional CO emissions and advancing our understanding of OH. It highlights key gaps in our current understanding and proposes novel solutions to address them. These advances are crucial in combating atmospheric pollution and understanding and tackling future climate change.
This thesis develops novel techniques to utilise 14CO to trace regional CO emissions and global oxidative capacity. Combining regional emissions with an atmospheric dispersion model, we use 14CO to understand CO sources on a regional scale. By 14CO production schemes into a largescale atmospheric model, we investigate its capacity as a tracer species for the hydroxyl radical (OH).
Our regional simulations demonstrate that 14CO can distinguish different CO emissions estimates in the UK and EU. Different emissions schemes show distinct Δ14CO-CO relationships indicating different fuel sources. We outline a measurement campaign that could be used to corroborate the results of our simulation study. Additionally, we provide the measured values necessary to conduct a similar study worldwide.
Our global study incorporated the latest cosmogenic 14CO production model into a global atmospheric model to carry out the first multi-decadal simulations to fully evaluate its capacity to trace the hydroxyl radical (OH). We also integrate secondary production of 14CO into an atmospheric model for the first time, investigating the role they play in surface concentrations.
Our results confirm the utility of 14CO as a tracer on a variety of spatial and temporal scales. This thesis deepens our understanding of 14CO as a tool in atmospheric science, offering unique insights into regional CO emissions and advancing our understanding of OH. It highlights key gaps in our current understanding and proposes novel solutions to address them. These advances are crucial in combating atmospheric pollution and understanding and tackling future climate change.
Date Issued
2024-07-18
Date Awarded
01/03/2025
License URL
Advisor
Graven, Heather
Publisher Department
Department of Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)