Hydrological Controls on Antarctic Ice-Sheet Tipping and Reversibility under Future Climate Change

About the research project

Antarctic ice loss is a major uncertainty in future sea-level projections. Water beneath the ice sheet can change basal friction, ice flow and freshwater discharge near grounding lines. However, Antarctic subglacial hydrology is poorly observed, and important hydrology-model parameters remain uncertain.

This PhD will determine how uncertainty within a subglacial hydrology model affects Antarctic ice-sheet projections, tipping thresholds and reversibility. The student will use Elmer/Ice, the Glacier Drainage System model (GlaDS), satellite observations and high-performance computing. The research has three connected chapters.

Chapter 1: Hydrological parameter uncertainty in a coupled Antarctic SSA–GlaDS model

The student will create an ensemble by varying selected GlaDS parameters while keeping the ice-sheet configuration and climate forcing controlled. Parameters may govern distributed water flow, channel development, water storage, cavity opening and closure, and basal water supply. The study will identify which parameters most strongly affect effective pressure, drainage configuration and grounding-line freshwater discharge. Satellite observations of active subglacial lakes, inferred drainage pathways and other available evidence will be used to evaluate and, where possible, constrain the ensemble. This chapter will establish which hydrological properties are supported by observations and which remain uncertain.

Chapter 2: Improved Antarctic projections using a constrained coupled ice–hydrology model

The observation-constrained coupled ice–hydrology ensemble developed in Chapter 1 will be used to produce improved Antarctic ice-sheet projections under Ice Sheet Model Intercomparison Project Phase 7 (ISMIP7) climate forcing. Unlike conventional projections that prescribe or simplify subglacial hydrology, these experiments will simulate evolving water pressure and its effects on basal friction, ice velocity and grounding-line retreat. The research will quantify how hydrology influences projected ice loss and sea-level contribution, identify the Antarctic regions most sensitive to hydrological change, and determine how much projection uncertainty remains across the constrained ensemble. The resulting projections will provide the foundation for the tipping-point experiments in Chapter 3.

Chapter 3: Hydrological controls on Antarctic tipping thresholds and reversibility

Experiments aligned with the Tipping Point Modelling Intercomparison Project (TIPMIP) will test whether hydrology changes the forcing threshold for self-sustained retreat, the duration of climate overshoot that can be tolerated, and the potential for recovery when forcing declines. The study will assess whether different plausible hydrological states produce different tipping or recovery pathways.

The student will join the Antarctic research community in Hobart and engage with IMAS, AAPP, ACEAS, ISMIP7 and TIPMIP researchers. The project is primarily computational; Antarctic fieldwork is not required.

Primary supervisor

Meet Doctor Chen Zhao

Funding

Applicants will be considered for a Research Training Program (RTP) scholarship or Tasmania Graduate Research Scholarship (TGRS) which, if successful, provides:

• a living allowance stipend funded by University of Tasmania of $34,315 per annum for 3.5 years
• a relocation allowance of up to $2,000
• a tuition fees offset covering the cost of tuition fees for up to four years (domestic applicants only)

A tuition fee offset may be offered to eligible international applicants following competitive assessment 

As part of the application process you may indicate if you do not wish to be considered for scholarship funding.

Other funding opportunities and fees

For further information regarding other scholarships on offer, and the various fees for undertaking a research degree, please visit our Scholarships and fees on research degrees page.

Eligibility

Applicants should review the Higher Degree by Research minimum entry requirements.

Ensure your eligibility for the scholarship round by referring to our Key Dates.

Additional eligibility criteria specific to this project/scholarship:

• Subject to University and scholarship requirements, applications may be considered from domestic and international applicants.
• Applicants must satisfy the University of Tasmania’s minimum Higher Degree by Research entry requirements.

Selection criteria

The project is competitively assessed and awarded. Selection is based on academic merit and suitability to the project as determined by the College.

Additional essential selection criteria specific to this project:

• A strong honours or master’s degree, or equivalent research experience, in glaciology, geophysics, climate science, applied mathematics, physics, engineering, Earth science or a related quantitative discipline.
• Demonstrated ability in numerical analysis, scientific programming or computational modelling.
• Ability to analyse complex results, work independently and communicate research clearly.
• Interest in Antarctic ice-sheet processes, climate change and sea-level rise.

Additional desirable selection criteria specific to this project:

• Experience with Python, MATLAB, Fortran, C/C++ or another scientific programming language.
• Experience with ice-sheet, glacier, hydrology, ocean or Earth-system models.
• Familiarity with satellite observations, geospatial analysis, NetCDF data, ensemble modelling or uncertainty quantification.
• Experience using Linux, version control or high-performance computing.

Application process

1. Select your project, and check that you meet the eligibility and selection criteria, including citizenship;
2. Contact Doctor Chen Zhao to discuss your suitability and the project's requirements; and
3. In your application:
   • Copy and paste the title of the project from this advertisement into your application. If you don’t correctly do this your application may be rejected.
   • Submit a signed supervisory support form, a CV including contact details of 2 referees and your project research proposal.
4. Apply prior to 1 October 2026.

Full details of the application process can be found under the ' How to apply ' section of the Research Degrees website.

Following the closing date applications will be assessed within the College. Applicants should expect to receive notification of the outcome by email by the advertised outcome date.

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