Leaky Ocean Eddies


Leaky Ocean Eddies


Project Description


Dr Xiaoming Zhai, University of East Anglia – Contact me

Professor Helen Johnson, Department of Earth Sciences, University of Oxford

Dr Hayder Salman, School of Mathematics, University of East Anglia

Scientific background

Mesoscale eddies are ubiquitous and most energetic features of the global ocean circulation. They play a key role in transporting and redistributing climatically important properties such as mass, heat, carbon and nutrients. However, the mechanisms by which ocean eddies transport these properties are still under debate. At the centre of this debate is the unknown ability of ocean eddies to trap and translate fluid, i.e., how leaky are ocean eddies? The aim of this project is to examine the ocean eddy trapping efficiency using both ocean models and satellite observations, identify the key parameters and physical processes, and determine the dominant mechanism(s) of eddy transport in the ocean.

Research Methodology

You will join a productive research team of physical oceanographers and fluid dynamists at UEA and the University of Oxford. You will identify and track eddy structures in both idealized and realistic ocean models as well as in satellite observations using popular Eulerian methods that are based on instantaneous information of the flow field. You will use Lagrangian particles to quantify the leakiness of these Eulerian eddies in material transport and determine ocean eddy trapping efficiency. You will identify Lagrangian coherent structures in simple and complex turbulent flows and diagnose lateral transport by these Lagrangian structures. You will determine the dominant mechanism by which ocean eddies transport properties and develop methods to improve eddy parameterization schemes used in current Earth System Models.


This project will provide you with a thorough training in numerical modelling, fluid dynamics and data analysis. Researchers at UEA and Oxford regularly lead and take part in field campaigns and we anticipate that you will participate in an ocean research cruise to gain oceanographic observational expertise. There will also be opportunities for you to attend summer schools and visit collaborating institutions.

Person specification

We seek an enthusiastic candidate with strong scientific interests and self-motivation. They will have at least a 2.1 honours degree in physics, mathematics, oceanography, meteorology, or climate science with good numerical skills.


  • 1 Ni, Q., X. Zhai, G. Wang, and D. P. Marshall (2020) Random movement of mesoscale eddies in the global ocean, Journal of Physical Oceanography, 50, 2341-2357.
  • 2 Salman, H., J. S. Hesthaven, T. Warburton, and G. Haller (2007) Predicting transport by Lagrangian coherent structures with a high-order method, Theor. Comput. Fluid Dyn., 21, 39-58.Salman, H., J. S. Hesthaven, T. Warburton, and G. Haller (2007) Predicting transport by Lagrangian coherent structures with a high-order method, Theor. Comput. Fluid Dyn., 21, 39-58.
  • 3 Zhai, X., H. L. Johnson, and D. P. Marshall (2010) Significant sink of ocean eddy-energy near western boundaries, Nature Geoscience, 3, 608-612.
  • 4 Abernathey, R., and G. Haller (2018) Transport by Lagrangian vortices in the Eastern Pacific, Journal of Physical Oceanography, 48, 667-685.
  • 5 Dong, C., J. C. McWilliams, Y. Liu, and D. Chen (2014) Global heat and salt transports by eddy movement, Nature Communications, 5, 3294.

Key Information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1st October 2024. The closing date for applications is 23:59 on 10th January 2024.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£18,622 p.a. for 2023/24) and research funding. International applicants are eligible for fully-funded ARIES studentships including fees. Please note however that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK. We expect to award between 4 and 6 studentships to international candidates in 2024.
  • ARIES students benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences, on top of all Research Costs associated with the project. Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses.
  • ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage enquiries and applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation and transgender status. Academic qualifications are considered alongside non-academic experience, and our recruitment process considers potential with the same weighting as past experience.
  • All ARIES studentships may be undertaken on a part-time or full-time basis, visa requirements notwithstanding.
  • For further information, please contact the supervisor. To apply for this Studentship follow the instructions at the bottom of the page or click the 'apply now' link.
  • ARIES is required by our funders to collect Equality and Diversity Information from all of our applicants. The information you provide will be used solely for monitoring and statistical purposes; it will remain confidential, and will be stored on the UEA sharepoint server. Data will not be shared with those involved in making decisions on the award of Studentships, and will have no influence on the success of your application. It will only be shared outside of this group in an anonymised and aggregated form. You will be ask to complete the form by the University to which you apply.
  • ARIES funding is subject to UKRI terms and conditions. Postgraduate Researchers are expected to live within reasonable distance of their host organisation for the duration of their studentship. See https://www.ukri.org/publications/terms-and-conditions-for-training-funding/ for more information

Applications open

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