University of Exeter funding: NERC GW4+ DTP PhD studentship

Next-generation model for plant ozone damage: a big step towards smaller uncertainties and more robust climate predictions. PhD in Mathematics (NERC GW4+ DTP) Ref: 3703

About the award


Lead Supervisor  

Prof Nadine Unger, Department of Mathematics, College of Engineering, Mathematics and Physical Sciences, University of Exeter

Additional Supervisors

Prof Stephen Sitch, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Dr Lina Mercado, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Dr Alex Cheesman. College of Science and Engineering, James Cook University, Cairns, Australia

Prof Lucas Cernusak, College of Science and Engineering, James Cook University, Cairns, Australia

Dr Gerd Folberth, Met Office

Location: University of Exeter, Streatham Campus, Exeter, EX4 4QJ

This project is one of a number that are in competition for funding from the NERC GW4+ Doctoral Training Partnership (GW4+ DTP).  The GW4+ DTP consists of the GW4 Alliance of research-intensive universities: the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five unique and prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory.  The partnership aims to provide a broad training in the Earth, Environmental and Life sciences, designed to train tomorrow’s leaders in scientific research, business, technology and policy-making. For further details about the programme please see

For eligible successful applicants, the studentships comprises:

  • A stipend for 3.5 years (currently £15,009 p.a. for 2019/20) in line with UK Research and Innovation rates
  • Payment of university tuition fees;
  • A research budget of £11,000 for an international conference, lab, field and research expenses;
  • A training budget of £3,250 for specialist training courses and expenses.
  • Travel and accommodation is covered for all compulsory DTP cohort events
  • No course fees for courses run by the DTP

We are currently advertising projects for a total of 10 studentships at the University of Exeter.


Students who are resident in EU countries are eligible for the full award on the same basis as UK residents.  Applicants resident outside of the EU (classed as International for tuition fee purposes) are not eligible for DTP funding. Residency rules are complex and if you have not been resident in the UK or EU for the 3 years prior to the start of the studentship, please apply and we will check eligibility upon shortlisting.

Project Background

Ozone holds centre stage in the chemical composition of the troposphere. Ozone is a secondary pollutant formed through photochemical reactions of nitrogen oxides (NOx) with volatile organic compounds (VOC) from both natural and man-made sources. It is an important greenhouse gas and harmful to human health and ecosystem integrity and welfare. Once ozone has entered the plants via the leaf stomata it interferes strongly with the leaf’s biochemistry leading to reduced photosynthetic productivity, early leaf senescence and even to partial or total leaf necrosis (Ainsworth et al., 2012). The consequences of reduced productivity include reduced plant growth, and reduced carbon drawdown from the atmosphere, thus acting as a large but uncertain indirect effect on climate. 

The recent IPCC special report on the impacts of global warming of 1.5 °C published in 2018 specifically emphasized the impacts of ozone mitigation on terrestrial ecosystems and the carbon cycle as a key uncertainty.

Project Aims and Methods 

For this CASE PhD studentship you will develop a more mechanistic and more universally applicable model of plant damage by ozone in the JULES model (the land component of the Met Office climate model). New and cutting edge ozone sensitivity measurements from tropical plants will be obtained through a collaboration with the Trop-Oz1 project (Sitch et al., 2018-21) in which the MO is a research partner. You will have the opportunity to collaborate on the physiological measurements conducted in Trop-Oz at JCU Cairns, Australia. 

Research Objectives : 

●  RO1: To collect the necessary physiological measurements to inform RO2 . This objective includes an extended literature review, and the opportunity to participate in one or more Trop-Oz field campaigns in Australia. 

 RO2 To develop a more mechanistic and universal approach to model ozone plant damage based on physiological measurements, plant traits, growth rates, leaf phenology and allocation. The development will build on the existing ozone leaf damage model by Sitch et al. (2007) in JULES but greatly extend its skill. 

●  RO3: To provide the first assessment of the impacts of ozone on tropical cash crops, for example, cocoa and oil palm.

●  RO4: To quantify the direct and indirect radiative forcing due to ozone leaf damage for the next IPCC assessment.


Net assimilation rate against leaf internal [CO2] for Ochroma pyramidale under ambient and low-O3 conditions b) Ficus insipida leaf exhibiting damage under high O3 fumigation (Pilot Study in Panama)


Climate control Greenhouse structure at James Cook University’s Environmental Research Complex. Greenhouse consists of three self-contained bays each 15 m2 with independent temperature, [CO2] and after augmentation O3 control

Candidate Requirements

The candidate will possess a strong BSc (and ideally MSc level) degree in Mathematics, Physics, Chemistry, Geography, Natural Sciences or a similar discipline. The candidate will be numerate, a strong problem solver and preferably have experience in field work and/or numerical modelling.

CASE or Collaborative Partner

The new ozone plant damage model will feed directly into the next generation of the MO-NERC community Earth system model UKESM. The Case partner will help guide the model developments in JULES and facilitate inclusion of the new code into the Earth System Model. The student will gain experience at working alongside scientists at a research institute, key to delivering the most up to date science on climate change to the IPCC.


The student will receive expert training in atmospheric chemistry, ecosystem and land carbon cycle science, developing and applying Earth System models, and analysing large datasets. Empirical field-based training at JCU Australia will include: measuring leaf-gas exchange using a LICOR 6400; planning, and executing field manipulation experiments; and statistical and data analysis techniques. Additional training will include scientific writing, science communication, project management and field-based health and safety.

References / Background reading list

Ainsworth, E. A., et al., The Effects of Tropospheric Ozone on Net Primary Productivity and Implications for Climate Change. Annu. Rev. Plant Biol., 63, 6637-661, 2012. 

Sitch, S., P. M. Cox, W. J. Collins, and C. Huntingford, Indirect radiative forcing of climate change through ozone effects on the land-carbon sink. Nature, 448, doi:10.1038/nature06059, 2007. 

Sitch, S., N. Unger, L. Mercado, G. E. Mills, F. Hayes, T. Hill, H. Harmens, A. Cheesman, , 2018-21. 

Young, P.J., et al., Pre-industrial to end 21st century projections of tropospheric ozone from the Atmospheric Chemistry and Climate Model Intercomparisons Project (ACCMIP). Atmospheric Chemistry and Physics, 13, 2063–2090,, 2013.

Yue, X., N. Unger, K. Harper, X. Xia, H. Liao, T. Zhu, J. Xiao, Z. Feng, and J. Li, Ozone and haze pollution weakens net primary productivity in China. Atmospheric Chemistry and Physics, 17, 6073-6089, doi:10.5194/acp-17-6073-2017, 2017.

Yue, X., and N. Unger, Fire air pollution reduces global terrestrial productivity. Nature Communications, 9, doi:10.1038/s41467-018-07921-4, 2018.

Entry requirements

Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK.   Applicants with a Lower Second Class degree will be considered if they also have Master’s degree.  Applicants with a minimum of Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.

All applicants would need to meet our English language requirements by the start of the  project

How to apply

In the application process you will be asked to upload several documents.  Please note our preferred format is PDF, each file named with your surname and the name of the document, eg. “Smith – CV.pdf”, “Smith – Cover Letter.pdf”, “Smith – Transcript.pdf”.

  • CV
  • Letter of application outlining your academic interests, prior research experience and reasons for wishing to undertake the project.
  • Transcript(s) giving full details of subjects studied and grades/marks obtained.  This should be an interim transcript if you are still studying.
  • If you are not a national of a majority English-speaking country you will need to submit evidence of your current proficiency in English.

Reference information
You will be asked to name 2 referees as part of the application process, however we will not expect receipt of references until after the shortlisting stage. Your referees should not be from the prospective supervisory team.

If you are shortlisted for interview, please ensure that your two academic referees email their references to the, 7 days prior to the interview dates.  Please note that we will not be contacting referees to request references, you must arrange for them to be submitted to us by the deadline.

References should be submitted by your referees to us directly in the form of a letter. Referees must email their references to us from their institutional email accounts. We cannot accept references from personal/private email accounts, unless it is a scanned document on institutional headed paper and signed by the referee.

All application documents must be submitted in English. Certified translated copies of academic qualifications must also be provided.

The closing date for applications is 1600 hours GMT Monday 6 January 2020.  Interviews will be held between 10 and 21 February 2020.  For more information about the NERC GW4+ DPT please visit

If you have any general enquiries about the application process please email  Project-specific queries should be directed to the lead supervisor.

Data Sharing
During the application process, the University may need to make certain disclosures of your personal data to third parties to be able to administer your application, carry out interviews and select candidates.  These are not limited to, but may include disclosures to:

  • the selection panel and/or management board or equivalent of the relevant programme, which is likely to include staff from one or more other HEIs;
  • administrative staff at one or more other HEIs participating in the relevant programme.

Such disclosures will always be kept to the minimum amount of personal data required for the specific purpose. Your sensitive personal data (relating to disability and race/ethnicity) will not be disclosed without your explicit consent.


Application deadline:6th January 2020
Value:£15,009 per annum for 2019-20
Duration of award:per year
Contact: PGR Enquiries