How do natural and ship emissions influence marine atmospheric sulfur, aerosol composition and acidity?


To apply please use the online application form. Simply search for PhD Chemistry (and select the entry point of October 2023), then clearly state that you are applying for a PhD studentship and name the project at the top of your personal statement.

Online application

Before applying, please ensure you have read the Doctoral College’s general information on applying for a research degree.

For more information on the admissions process please contact

Director of Studies: Professor Thomas Bell (, Plymouth Marine Laboratory
2nd Supervisor: Dr Mingxi Yang, Plymouth Marine Laboratory
3rd Supervisor: Dr Simon Ussher
4th Supervisor: Professor Alex Archibald (, University of Cambridge
Applications are invited for a 3.5 years PhD studentship. The studentship will start on 01 October 2023.

Project description 

Scientific background
Sulfur plays a key role in the marine atmosphere, and has a major influence on atmospheric particles and climate. Marine sulfur emissions result from natural biological processes as well as anthropogenic activities. Sulfur impacts the composition and acidity of atmospheric particles (aerosols), which is fundamental in atmospheric chemistry and relevant to air quality, ecosystems, and climate. 
The marine atmosphere is changing profoundly: Terrestrial regulations since the 1980s and a 2020 global mandate to reduce ship emissions seven-fold aimed to improve air quality and have significantly reduced anthropogenic sulfur emissions. Furthermore, recent discoveries of new atmospheric sulfur molecules are forcing a radical re-examination of the role of natural marine sulfur in the climate system. Natural/anthropogenic contributions to the marine sulfur burden and impacts on aerosol acidity are poorly understood because there has been no post-2020 assessment of the marine sulfur cycle. 
Project aim
Constrain natural and anthropogenic sulfur emissions, understand present-day atmospheric sulfur cycling, and determine the impacts upon the marine atmosphere.
Research methodology  
The student will analyse marine sulfur gas concentrations and fluxes on a dedicated research campaign in the Atlantic, and will assess aerosol composition and natural/anthropogenic sources using isotope ratios in samples from Penlee Point (UK), the Azores (ACE-ENA), and Bermuda (Tudor Hill). All data will be evaluated against the UKCA model to improve understanding of marine aerosol, acidity and the impacts on biogeochemical cycles. 
Training opportunities
The student will gain field experience (research cruise and observatory site visits) and analytical lab experience in ISO accredited labs (PML Air-Sea Exchange group: Time-of-Flight Mass Spectrometry, and UoP: Ion Chromatography and Inductively Coupled Plasma Mass Spectrometry). They will attend the annual UKCA training course, gain data interpretation skills (Python), and learn valuable academic, industrial and consultancy career skills (e.g. transferable writing and presentation skills, good laboratory practice, quality assurance and safety procedures). 
Person specification
Suited for someone passionate about multidisciplinary environmental research and field work, with an aptitude for operating scientific instrumentation and degree-level qualifications in Environmental, Chemical, Marine or Atmospheric Sciences. Those with other numerate degrees (e.g. Physics, Engineering) are also encouraged to apply.
Funding notes
This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1 October 2023.
Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship for 3.5 years, covering fees, stipend (£17,668 p.a. for 2022-23 rate) and research funding. International applicants (EU and non-EU) are eligible for fully-funded UKRI studentships.
ARIES students benefit from bespoke graduate training and £2,500 for external training, travel and conferences.
ARIES is committed to equality, diversity, widening participation and inclusion. Academic qualifications are considered alongside non-academic experience. Our recruitment process considers potential with the same weighting as past experience.
For information and full eligibility visit
Please clearly state the name of the studentship project code BELL_PPML23ARIES that you are applying for on your personal statement.
Please see our 'how to apply for a research degree' page for a list of supporting documents to upload with your application.
If you wish to discuss this project further informally, please contact Professor Thomas Bell,
For more information on the admissions process generally, please contact
The closing date for applications is 23:59 (UK Time) 11 January 2023. 


1Yang et al. (2016). Attribution of atmospheric sulfur dioxide over the EnglishChannel to dimethyl sulfide and changing ship emissions, Atmospheric Chemistryand Physics

2Veres et al. (2020). Global airborne sampling reveals a previously unobserveddimethyl sulfide oxidation mechanism in the marine atmosphere, Proceedings ofthe National Academy of Sciences

3Baker et al. (2021). Changing atmospheric acidity as a modulator of nutrientdeposition and ocean biogeochemistry, Science Advances 

4Hattori et al. (2021). Isotopic evidence for acidity-driven enhancement ofsulfate formation after SO2 emission control, Science Advances 

5Yu et al. (2020). Characterizing the particle composition and cloudcondensation nuclei from shipping emission in Western Europe. Env. Sci. &Tech.