Southern Ocean winter water as a climate model diagnostic and fingerprint of winter mixed layer variability


Southern Ocean winter water as a climate model diagnostic and fingerprint of winter mixed layer variability


Project Description


Professor Karen Heywood (School of Environmental Sciences, University of East Anglia) – Contact me

Professor David Stevens (School of Mathematics, University of East Anglia)

Dr Helene Hewitt (Hadley Centre, UK Met Office)

Dr Patrick Hyder (Hadley Centre, UK Met Office)


Project Background

The Southern Ocean is a critical component of the global climate system, where heat is lost from the ocean to the atmosphere, strong winds stir and mix the waters, and sea ice forms and melts. Variations in the temperature and saltiness of Winter Water (the remnant of the previous winter’s near-surface ocean layer) may reveal previous interactions between ocean, ice and atmosphere. Despite its importance, processes responsible for Winter Water formation are not well understood (Pellichero et al., 2017), nor are they thought to be well represented in current Earth System Models. This project will explore Winter Water and its spatial and temporal variability, in both newly-available Southern Ocean observational data sets and the UK’s climate models, determine the underlying physical mechanisms, and test Winter Water layer depth as a metric to assess Earth System Model performance.

Research Methodology

You will join a productive research team of physical oceanographers and climate modellers at UEA and the Met Office in Exeter (CASE partner). You will analyse Winter Water temperature, saltiness and depth in observations from tagged seals, research ships and profiling floats. You will assess the performance of the UK’s climate models at different resolutions and with different mixing parameterizations in simulating Winter Water and its variability. You will use simplified models to investigate the key physical processes responsible for Winter Water formation, e.g. air-sea interaction or sea ice formation/melting. You will test the hypothesis that Winter Water depth is a more robust indicator than mixed layer depth of Earth System Model performance.


This project will provide you with a thorough training in physical oceanography, data analysis, numerical modelling, and interactions between ocean, ice and atmosphere. We anticipate that you will participate in a Southern Ocean field campaign to gain oceanographic observational expertise. The project will equip you for a wide variety of careers, e.g. ocean/climate research, marine industries, consultancy or numerical modelling.

Person specification

You will be keen to learn about the physics of the ocean and will have studied natural sciences, physics, mathematics, oceanography, meteorology, or environmental sciences with good numerical skills.


  • 1) Heuzé, C., K.J. Heywood, D.P. Stevens, and J.K. Ridley (2013) Southern Ocean bottom water characteristics in CMIP5 models, Geophysical Research Letters, 40, 1409-1414.
  • 2) Mallett, H.K.W., L. Boehme, M. Fedak, K.J. Heywood, D.P. Stevens, and F. Roquet (2018) Variation in the distribution and properties of Circumpolar Deep Water in the eastern Amundsen Sea, on seasonal timescales, using seal-borne tags, Geophysical Research Letters, 45, 4982-4990.
  • 3) Heuzé, C., K.J. Heywood, D.P. Stevens and J.K. Ridley (2015) Changes in global ocean bottom properties and volume transports in CMIP5 models under climate change scenarios, Journal of Climate, 28, 2917-2944.
  • 4) Pellichero, V., Sallée, J.-B., Schmidtko, S., Roquet, F., and Charrassin, J.-B. (2017), The ocean mixed layer under Southern Ocean sea-ice: Seasonal cycle and forcing, J. Geophys. Res. Oceans, 122, 1608– 1633, doi:10.1002/2016JC011970.
  • 5) Zheng, Y., Heywood, K.J., Webber, B.G.M. , Stevens, D.P. et al. Winter seal-based observations reveal glacial meltwater surfacing in the southeastern Amundsen Sea. Commun Earth Environ 2, 40 (2021).

Key Information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1st October 2022. The closing date for applications is 23:59 on 12th January 2022.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£15,609 p.a. for 2021-22) and research funding. International applicants (EU and non-EU) are eligible for fully-funded UKRI studentships. Please note ARIES funding does not cover visa costs (including immigration health surcharge) or other additional costs associated with relocation to the UK.
  • ARIES students benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences. 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 in the subject area.
  • 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 click on the “Apply now” link below.
  • 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.

Applications are open

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