Photo of the head and shoulders of a man.

Thomas Wynn

University of Birmingham

Project

Reducing ammonia emissions is key to meet the UK’s new air quality target

Supervisors

  • Prof Zongbo Shi
  • Dr Ying Chen
  • Dr James Brean
  • Dr Siqi Hou
  • Dr Pablo Espina Martin
  • Dr Chiara Di Marco
  • Dr Zhe Tian 

PhD Summary

This project will measure atmospheric ammonia (NH3) concentrations throughout the West Midlands at a high time resolution using a mobile air quality supersite (part of the UK Air Quality Supersite Triplet (UK-AQST)) equipped with a high time resolution NH3 monitor alongside other air quality instruments. NH3 concentrations will also be measured in the West Midlands at 2 long-term fixed location sites using the same high time resolution instrument alongside a large array of other air quality instruments. Inversion modelling will be used to quantify the sources of NH3 in the West Midlands to update the emission inventories in WRF-Chem (Weather Research and Forecasting model coupled with Chemistry). Subsequently air quality models will be used to assess how to best reduce ammonia emissions and consequently reduce PM2.5 (Particulate Matter less than 2.5 micrometers in diameter) concentrations. Additionally, using the updated WRF-Chem model, we will quantify the impact NH3 has upon PM2.5 formation. The findings will inform policy recommendations for reducing and controlling ammonia emissions, shared with DEFRA, The Air Quality Expert Group, and WM-Air. 

Previous activity

I completed my BSc (Hons) in Environmental Science at the University of Birmingham in July 2024. My undergraduate dissertation investigated air quality (PM2.5) onboard public transport in the West Midlands using low-cost sensors. 

During summer 2023 I undertook an 8-week CENTA Research Experience Placement (REP) with UKCEH, researching urban atmospheric ammonia (NH3) in Birmingham to understand and quantify NH3’s spatial variation in an urban area. I conducted my own sampling campaign measuring NH3 concentrations in Edgbaston (Birmingham) using passive UKCEH ALPHA samplers (Adapted Low-cost Passive High Absorption). NH3 concentrations were measured at 10 strategically placed sites around Edgbaston, Birmingham, in order to quantify the contribution each NH3 source has upon the overall atmospheric NH3 concentration. I also carried out a literature review to summarise the urban NH3 research from the past 10 years. I then presented my work and this sampling campaign in front of Defra at the quarter 3 UKEAP meeting (UK Eutrophying and Acidifying Pollutants).  

Why did you choose doctoral research?

Throughout my undergrad I became really interested and fascinated by air pollution. Doing research during my degree was something that I always enjoyed as you get to find out something new and to gain a deeper understanding of a topic. My CENTA REP really solidified this and showed that after my undergrad I definitely wanted to continue doing air pollution research as it was so enjoyable and interesting and allowed me to learn so much about air pollution. Doing a PhD gives me the opportunity to gain a much deeper understanding of the emissions and atmospheric processing of air pollution, particularly ammonia, as well to contribute to scientific research and to further the current scientific understanding of air pollution, something which I am very keen on doing. 

Why did you choose CENTA?

A CENTA studentship allowed me to design my own PhD research project so that I could tailor it to exactly fit my research interests as there was not an advertised project which focused on my specific area of interest, atmospheric ammonia. Additionally, designing my own project allowed me to shape it such that I could develop skills in specific areas that I want to learn about such as modelling which I have never done before. 

Future plans

This project will equip me with a very large range of skills, knowledge and experience which will make me highly employable both as an atmospheric scientist and as a modeller. Firstly, air quality observations where I will gain a large amount of skills and experience in making air pollution measurements including setting up, running and maintaining a large range of air quality instruments. Secondly, advanced air quality modelling where I will gain experience in running air quality models, perturbed emission ensemble, and inversion modelling. Thirdly, I will gain a large amount of knowledge and experience in atmospheric chemistry of both the emissions and atmospheric processing of air pollutants.  

I would really like to stay in academia and continue doing research so that I can keep deepening my understanding of air pollution and continue to advance our current scientific understanding.