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Award details

University of Exeter funding: NERC GW4+ DTP PhD studentship

Effects of rapid Arctic climate change on jet streams and extreme weather. Mathematics PhD Studentship (NERC GW4+ DTP funded) Ref: 4015

About the award


Lead Supervisor

Dr Stephen I. Thomson, Univ. of Exeter, Mathematics

Additional Supervisors

Prof. Dann Mitchell, Univ. of Bristol, Geography

Prof. James Screen, Univ. of Exeter, Mathematics

Dr Will Seviour, Univ. of Exeter, Mathematics

Dr Doug Smith, Met Office

Location: Streatham Campus, University of Exeter, Exeter, Devon.

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP).  The GW4+ DTP consists of the Great Western Four alliance of the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five Research Organisation partners:  British Antarctic Survey, British Geological Survey, Centre for Ecology and Hydrology,  the Natural History Museum and Plymouth Marine Laboratory.  The partnership aims to provide a broad training in earth and environmental sciences, designed to train tomorrow’s leaders in earth and environmental science. For further details about the programme please see

For eligible successful applicants, the studentships comprises:

  • An stipend for 3.5 years (currently £15,285 p.a. for 2020-21) 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.
  • Up to £750 for travel and accomodation for compulsory cohort events.

Project details

Project Background

The lower atmospheric warming as a result of manmade CO2 emissions is several times larger in the Arctic than in other parts of the world (see figure 1), a phenomenon known as Arctic Amplification. The importance of this amplified warming could extend well beyond the Arctic, however. The midlatitude jet streams (figure 2), and their associated storm tracks, are effectively powered by the temperature difference between the warmer low latitudes and the colder high latitudes. Arctic amplification decreases this temperature gradient in the lowermost atmosphere, potentially impacting the jet stream and storms. Such changes could lead to an increase in extreme weather, which is a particular concern for the lives and livelihoods of the billions of people who live under the path of the jet stream [e.g., Cohen et al., 2014].  Arctic amplification is a robust phenomenon that appears clearly in state-of-the art climate models, and is relatively well understood. However, the response of the jet stream to Arctic amplification is far more uncertain, and varies substantially between different climate model experiments (Screen et al., 2018; Screen and Blackport, 2019). Until we better understand the ways that the jet stream is affected by Arctic amplification, we cannot skilfully predict future changes in extreme weather, which is a significant problem. This lack of a robust jet stream response across models may reflect differences in how they simulate the present-day climate, as this is known to influence how they subsequently respond to changes in forcing, such as CO2 levels (e.g. Thomson & Vallis 2018). For example, the average location of the jet stream is further north in some models than others, which might affect how strongly the jet stream is affected by Arctic amplification in a one model compared to another (Smith et al., 2017).  By understanding what causes models to differ, we seek to reduce uncertainty in future projections of midlatitude climate and extreme weather.

Figure 1: Temperature changes under RCP8.5 from 31 CMIP5 models, scaled for 1 degree of global-average temperature change, from Smith et al, 2019.

Figure 2: Latitudinal distribution of the westerly wind in N.Hemisphere winter from a simulation using the Isca climate model, from Thomson & Vallis 2020.

Project Aims and Methods

To investigate the jet stream response to Arctic amplification, we will conduct experiments using a new, relatively simple but highly configurable global climate model known as Isca, developed by Dr Thomson and others at Exeter ( Isca has the ability, unlike most climate models, to be able to turn relevant processes on and off.  By using these features, we can investigate how jet stream responds to Arctic amplification in a controlled manner, and ascertain which processes are the most important. Isca also has the advanced capability to ‘nudge’ the atmosphere to different background states, allowing us to test how much factors such as the average jet stream location matter for the jet steam response to Arctic amplification. We will also make use of output of new experiments already run using sophisticated climate models as part of the Polar Amplification Model Intercomparison Project (PAMIP; Smith et al., 2019) lead by Dr Smith and Prof Screen. We will combine the data from PAMIP and results from Isca to understand better how biases in present day climate can influence predictions of jet stream properties, and the impacts on extreme weather. The student will have the opportunity to join a major new collaboration on Arctic-tomidlatitude teleconnections, which also includes scientists at the Universities of Bristol, Oxford, Reading, Bangor, Southampton, and the National Oceanography Centre. This will give the student opportunities to present at project meetings and spend time visiting other institutions.

Candidate requirements

The candidate must have achieved, or be expected to achieve, a first class or 2:1 degree in Meteorology, Oceanography, Mathematics, Physics, Environmental Science, or related field. A Master’s level qualification with previous experience of conducting independent research is desirable. Knowledge of scientific programming languages (e.g., Python, Matlab, R) would be advantageous, but is not essential.


The student will gain skills in high-performance computing, including the use of supercomputers, and software development. They will join existing collaborative networks involving the PAMIP project and Isca.

Background reading and references

Cohen et al 2014 (DOI:10.1038/ngeo2234)

Smith et al., 2017 (DOI:10.1175/JCLI-D-16-0564.1 )

Thomson & Vallis 2018 (DOI:10.1175/JAS-D-17-0297.1)

Screen et al., 2018 (DOI:10.1038/s41561-018-0059-y )

Smith et al., 2019 (DOI:10.5194/gmd-12-1139-2019 )

Screen and Blackport, 2019 (DOI:10.1029/2019GL084936 )

Thomson & Vallis 2020 (DOI:10.3390/atmos10120803)


NERC GW4+ DTP studentships are open to UK and Irish nationals who, if successful in their applications, will receive a full studentship including payment of university tuition fees at the home fees rate.

A limited number of full studentships are also available to international students which are defined as EU (excluding Irish nationals), EEA, Swiss and all other non-UK nationals.  For further details please see the NERC GW4+ website.

Those not meeting the nationality and residency requirements to be treated as a ‘home’ student may apply for a limited number of full studentships for international students. Although international students are usually charged a higher tuition fee rate than ‘home’ students, those international students offered a NERC GW4+ Doctoral Training Partnership full studentship starting in 2021 will only be charged the ‘home’ tuition fee rate (which will be covered by the studentship). International applicants need to be aware that you will have to cover the cost of your student visa, healthcare surcharge and other costs of moving to the UK to do a PhD. More information on this is available from the universities you are applying to (contact details are provided in the project description that you are interested in

The conditions for eligibility of home fees status are complex and you will need to seek advice if you have moved to or from the UK (or Republic of Ireland) within the past 3 years or have applied for settled status under the EU Settlement Scheme.


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 Friday 8 January 2021 2359 GMT .  Interviews will be held between 8th and 19th February 2021.  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:8th January 2021
Value:£15,285 per annum for 2020-21
Duration of award:per year
Contact: PGR Enquiries