Impacts of eddy damping on the ocean stratification and general circulation


Impacts of eddy damping on the ocean stratification and general circulation


Project Description


Dr David Munday, British Antarctic Survey – Contact me

Dr Xiaoming Zhai, University of East Anglia, School of Environmental Sciences

Dr Andrew Meijers, British Antarctic Survey

Scientific Background

Mesoscale eddies are small-scale ocean features, around 10-100 km in size, which are analogous to the atmosphere’s weather systems. They play many roles in the ocean circulation, such as transporting heat, salt and carbon over large distances, and influence climate as a result. Eddies result from instability processes, where small perturbations, such as temperature wiggles, grow rapidly from an otherwise stable circulation. However, it has been known for some time that eddies are not passively spawned from the ocean’s density distribution (its stratification); instead, they play an active role in setting the stratification of the ocean (Marshall et al., 2003). Consequently, processes that affect the eddy field can indirectly affect the stratification too. One such process is the relative wind stress effect, in which the wind stress at the surface of the ocean is calculated using the difference between the atmospheric wind and the ocean velocity. This introduces a drag on small-scale features, such as mesoscale eddies, that can directly dissipate them and have widespread effects on the ocean (Wilder et al., 2022; Munday et al., 2021; Renault et al., 2016).

Research Methodology

The student will use numerical models with simplified forcing and geometry to investigate how the relative wind effect impacts the role of eddies in setting ocean stratification. They will apply fundamental theories of ocean circulation to develop their understanding and quantitatively predict the stratification (see Marshall et al., 2002). By introducing the curvature of the Earth (the beta effect/plane), the student will extend their results to include this important extra effect and ultimately consider the stratification of wind-driven subtropical gyres (Radko & Marshall, 2003). Wind-driven gyres play key roles in the heat transport of the ocean and can influence climate in important ways.

Person Specification

This project would suit a mathematically inclined student with a degree in physics, mathematics or physical oceanography. Experience with Python, Matlab or Fortran would be an advantage, although all necessary training will be provided. An interest in the theory of ocean circulation and numerical modelling is essential. The student will be encouraged to participate in field work where the opportunity presents itself.


  • 1 T. Wilder, X. Zhai, D. Munday, and M. Joshi, 2022: The response of a baroclinic anticyclonic eddy to relative wind stress forcing, Journal of Physical Oceanography, 52, 2129–2142, doi:10.1175/JPO–D–22–0044.1.
  • 2 D. R. Munday, X. Zhai, J. Harle, A. C. Coward, and A. J. G. Nurser, 2021: Relative vs. absolute wind stress in a circumpolar model of the Southern Ocean., Ocean Modelling, 168, 101891, doi:10.1016/j.ocemod.2021.101891.D. R. Munday, X. Zhai, J. Harle, A. C. Coward, and A. J. G. Nurser, 2021: Relative vs. absolute wind stress in a circumpolar model of the Southern Ocean., Ocean Modelling, 168, 101891, doi:10.1016/j.ocemod.2021.101891.
  • 3 L. Renault, M. J. Molemaker, J. Gula, S. Masson, and J. C. McWilliams, 2016: Control and stabilization of the Gulf Stream by oceanic current interaction with the atmosphere, Journal of Physical Oceanography, 46, 3439–3453, doi:10.1175/JPO–D–0115.1.
  • 4 T. Radko and J. Marshall, 2003: Equilibration of a warm pumped lens on a β plane, Journal of Physical Oceanography, 33, 885–899, doi:10.1175/1520-0485(2003)332.0.CO;2.
  • 5 J. Marshall, H. Jones, R. Karsten, and R. Wardle, 2002: Can eddies set ocean stratification?, Journal of Physical Oceanography, 32, 26–38. doi:10.1175/1520-0485(2002)0322.0.CO;2.

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 for more information

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