The chemistry of the Atmosphere

The chemistry of the gases and particles present in the air around is hugely important area of research. We require a detailed understanding of atmospheric chemistry to enable new pathways to reduce air pollution and climate change. To study this topic requires an approach that combines fundamental laboratory studies on the physico-chemical properties of atmospheric constituents with observations of the abundance and variability of these moities and numerical model simulations that integrate our understanding of the sources and fate of these compounds and with which we can test hypothesis on how they will change under different conditions. In the Archibald team we combine these three approaches to enhance our understanding of the air around us. 

Dr Archibald discusses his research

The Archibald Team

We are a diverse team of research scientists and PhD students interested in better understanding what goes on in the atmosphere. 

2017-2018

2018-2019 with members of the Schmidt team and the Pyle team. 

2019-20 with members of the Schmidt Team and Pyle Team. 

2022

PhD Students

Xingpei Ye -- Visiting from Peking University

Sophie Turner -- 

Lorrie Jacob -- 

Print Sakulsupich -- 

Jayaprakash Murulitharan -- 

Seb Hickman -- 

Michelle Wan -- 

Matthew Shin -- 

Andrea Chlebikova -- SOAR³

Zosia Staniaszek -- Future Methane

Co-Supervised:

Omer Nivron -- 

Risa Ueno -- Improving predictions of future urban temperature extremes for improved energy demand.

Former students:

Wentai Zhang -- Visiting from Hong Kong University 

Jason Sun -- Improved estimates of the air pollution impacts on human health

Le Yuan -- Improving Air Quality for Beijing

James Weber -- Chemistry Climate Feedbacks in the Earth System. 

Ben Cala -- Improving the representation of DMS chemistry in UKCA. 2020-2021. 

Johnny Staunton-Sykes -- Volcanic Halogens

Lihang Pan -- A tale of two cities: Ozone trends and impacts in Beijing and New Delhi. 2019-2020. 

David Wade -- Paleo Composition Climate Interactions.

MPhil Students:

Selena Zhang -- Earth system impacts of near term climate overshoots. 

PostDocs and Research Assistants

Current:

Luke Abraham -- NCAS-Climate

Maria Russo -- NCAS-Climate

Paul Griffiths -- NCAS-Climate

Nicola Warwick -- NCAS-Climate

Megan Brown -- HECTER

Xu-Cheng He -- Visiting Fellowship, Helsinki, Finland. 

Former:

James Keeble 

Scott Archer-Nicholls 

Zainab Hakim 

Part III Students

2023-2024

2022-2023

Alex Mason 

Arsen Ismagilov 

Olivia Hooke

2021-22

Douglas Russel -- Attributing the role of aerosols and ozone precursors on the tropospheric ozone budget. 

Joanne Bell -- Arctic stratospheric ozone trends and causes.

Daniel Winter -- NAO-surface ozone correlations.

2020-21 

Hannah Bryant -- Arctic ozone holes: Frequency, causes and impacts.

Ioana Doran -- ACSIS: Impacts of fires on the North Atlantic. 

Shengxian Ke -- The impacts of COVID-19 on global tropospheric ozone. 

Matt Wright -- Reconciling the budget of ozone in the troposphere. 

2019-20

Imogen Lever -- The potential air quality and climate impacts of a future hydrogen economy 

Seb Hickman -- Simulating the chemistry of OH in the free troposphere: Simple models and machine learning

Tom Elgar -- Biosignatures as a sign of life? Modelling isoprene chemistry on exoplanets. 

Emilia O'Reilly -- The impacts of the Asian Summer Monsoon on atmospheric chemistry and transport.  

2018-19

Rachel Allen -- Trends in the NO3 radical: 1850-2100. 

Molly Harte -- Geoengineering: Solutions and impacts

Alice Cozens -- Geoengineering: Solutions and impacts

Jack Entwistle -- Evaluation of ATom aircraft campaign data in comparison to UKCA model

Domas Kalvaitis -- Can an exopllanet model simulate the chemistry of Earth?

2017-18

Matthew Shin -- Evaluating trends in tropospheric ozone over the UKCA model

Tom Surrall -- Evaluation of emission inventories of VOCs over India

Alec Granville-Willet -- Evaluation of Archean atmosphere HCHO photochemistry

Research Interests

Our research involves the development and application of state-of-the-art chemistry-climate models. With these models we are trying to answer a number of questions relevant to society: (i) What are the impacts of changes in man made emissions on the composition of the atmosphere (ii) how does the changing composition of the atmosphere affect climate (iii) how will a changing climate impact the composition of the atmosphere.

There are three main areas of research within the group:

• Understanding the fundamentals of gas phase chemistry in the atmosphere
• Understanding the impacts of changes in gases and particles on climate
• Understanding the impacts of changes in climate on gases and particles

Current funded projects

The North Atlantic Climate System Integrated Study: ACSIS

Oxidant Budgets of the Northern Hemisphere: OXBUDS

Process analysis, observations and modelling - Integrated solutions for cleaner air for Delhi: PROMOTE

Specific projects have included:

• The mechanisms of oxidation of biogenic hydrocarbons

One of the main areas of research in my group is trying to better understand the mechanisms of oxidation of biogenic hydrocarbons - in particular the oxidation of isoprene. Isoprene enters the atmosphere via emissions from plants and trees. Every year a mass roughly equal to that of the entire human population is emitted into the atmosphere! Owing to this, and its high reactivity, it is paramount to include isoprene chemistry in chemistry-climate models. However, the details of the chemistry vary wildly between models and isoprene chemistry has been suggested as a major cause of disagreement between model predictions of secondary pollutants. The figure below highlights some of the chemistry of isoprene oxidation initiated by the hydroxyl radical. 

• The impacts of fracking on air quality

In collaboration with the Met Office our group have also looked at the role of fracking in the UK, and the impacts of unconventional hydrocarbon extraction on air quality. For this work we use a version of the Met Office weather forecast model modified for simulating air pollution. The animation below shows the domain this model covers and the simulated levels of the pollutant ozone (O₃) from the model.  

• Long range transport of trace gases​

Gases that have lifetimes against chemical reaction in the atmosphere greater than a few days can be transported over great distances. The animation below shows how the ozone depleting substance methyl chloride (CH₃Cl) can be emitted from fires in Brazil and transported over several days and 100s of km across South America. Daily average observations of CH3Cl recorded at the AGAGE monitoring site in Barbados are plotted below the animation and you can see that there are several periods where "spikes" are seen in these data. We try to understand both the roles of atmospheric transport and chemistry over these long ranges to answer questions such as how will changes in emissions downwind of us impact the quality of the air we bretahe? 

For more information about the groups published work see my publications below and my Google scholar page. 

For more information about my work check out my ORCID profile. 

Teaching

I lecture the 1A kinetics course and a Part II course on Chemistry in the Atmosphere. 

You can find the handout for my 2020 kinetics course here (or if you are having trouble with that link try here too). 

Software

For those interested in looking at some simple numerical problems concerning atmospheric chemistry, feel free to have a play with this simple R script: https://bitbucket.org/alex_archibald/atmos_chem_model