Project summary
This project will investigate the influence of meltwater runoff and near-terminus subglacial hydrology on the dynamic stability of marine-terminating glaciers draining the Greenland Ice Sheet.
Background
The greatest store of fresh water in the northern hemisphere is held within the Greenland Ice Sheet (GrIS). Over recent decades, the ice sheet’s rate of mass loss has accelerated driven by a warming climate and substantial increases both in: 1) the speed of large marine terminating glaciers (MTGs) draining the ice sheet; and 2) surface melt rates and melt extent. However, while there is clear evidence intimating a role between meltwater and subglacial hydrology and MTG dynamics1 , the precise nature of these interactions, particularly over long (>5 yr) timescales remains very poorly understood. On shorter[1]time scales, in-situ2 and satellite3 based studies have revealed links between the seasonal evolution in both meltwater-runoff and subglacial hydrology and the dynamics of tidewater glacier termini. However, the extent to which any sustained changes in dynamics are driven by subglacial processes, as opposed to fjord processes operating at the ice-ocean interface and in particular submarine melting, remain unclear. Nevertheless, improved satellite data availability in conjunction with exciting developments in EO techniques to infer both glacier adjacent fjord-water properties (temperature, salinity and turbidity)4,5 and ice motion6 offers the exciting potential to investigate how both evolving subglacial hydrology and submarine melt processes impact longer term MTG dynamics with clear implications for GrIS mass loss.
Primary Supervisor: Peter Nienow <Peter.Nienow@ed.ac.uk>
Institution: University of Edinburgh
Academic Supervisors: Andrew Sole, Anna Hogg (A.E.Hogg@leeds.ac.uk – University of Leeds , School of Earth and Environment), Dr Ben Davison (B.Davison@leeds.ac.uk – University of Leeds, School of Earth and Environment), Dr Encarni Medina-Lopez (Encarni.Medina-Lopez@ed.ac.uk – University of Edinburgh, School of Engineering)
Aim and research questions
This project will use a range of earth observation data to investigate the influence of ice-sheet runoff, subglacial hydrology and near-terminus fjord processes on the long-term dynamic stability of MTGs draining the GrIS. More specifically, the project will quantify how ice-motion at Greenland’s MTGs has responded spatially and temporally to changes in subglacial discharge, near-terminus subglacial hydraulic efficiency and variations in calving and frontal (submarine) ablation. The project will be delivered via the following objectives:
O1) Determine, at high spatial and temporal resolution, how MTG velocity, terminus position and surface elevation have changed in recent decades at a suite of (~10) fast-flowing glaciers.
O2) Determine seasonal/inter-annual evolution in meltwater-runoff and subglacial hydraulic efficiency.
O3) Determine the distribution of fjordwater temperatures and associated submarine melt-rates.
O4) Determine how MTGs will respond dynamically to increased meltwater-runoff associated with projected climate warming.
Methodology and timetable
To address these objectives, the project will: O1) Analyse a wealth of available satellite data to derive ice-motion3,6 (Sentinel; Landsat) and surface elevation (CryoSat-2; IceSat) change over recent decades. O2) Determine meltwater runoff using the MAR climate model and subglacial hydraulic efficiency from sediment rich plume extent/visibility as detected using surface reflectance (LandSat-8 5 and MODIS7 ). O3) Derive ice-proximal fjord surface water temperatures and salinity4 from TOA reflectance (Sentinel-2) to better constrain plume extent and submarine melt-distribution; novel machine learning will be used to delineate the temperature/salinity fields and thus plume extent. O4) Estimate future MTG retreat using a parameterisation8 based on surface melt, subglacial hydraulic efficiency and fjord water temperatures.
Training provision and required skills
You will be supervised by a team of leading glaciologists and remote-sensing scientists, gaining expertise in advanced techniques in remote sensing, data manipulation, machine learning and modelling while being an integral part of the >20 strong world class cryosphere research group at Edinburgh. We seek an enthusiastic candidate equipped with advanced quantitative skills and a suitable degree including physics, mathematics, computer science, engineering, earth sciences or physical geography.
The Selection Process
Step 1
Application: Submit an application via the University of Leeds application portal. Step by step guidance is available here. The deadline for applications is 9th January 2022
Step 2
Selection: Your application will be reviewed by the supervisors of the project that you apply to, and SENSE’s recruitment committee who will read an anonymised application. We encourage you to get in touch with the supervisor of the project you are applying to, to discuss the project. If you are unsure about or would like support in contacting potential supervisors, or would like to contact them anonymously, please contact the centre managers (see ‘Questions’) at the bottom of this page.
Applicants will be invited for interview based on the following criteria:
- Score for Bachelor’s degree
- Score for master’s grade, or relevant industry experience
- References
- Any scientific outputs (not expected or essential, but let us know if you have any)
- Research skills / experience
- Technical experience
- Earth Observation experience
Please note that it is not necessary for a candidate to be proficient in all these areas: SENSE provides extensive training in Earth Observation, advanced data techniques and programming. We recruit candidates from a broad range of backgrounds and we consider each application individually.
Step 3
Interview. We will call the strongest applicants for interview. The interview panel will be Earth Observation academics from the University of Edinburgh, University of Leeds and industry, with a range of specialities, and will not include the project supervisor. Interviews will be held in Leeds in late February / early March 2022. We seek to make offers to students who have the best aptitude for the projects and who perform best at interview.
Step 4
Offer. We will make a formal offer to the successful candidate shortly after interviews.
Once you accept the offer of the study place, you will be sent a formal funding letter.
Deadline
The application deadline is Sun 9th January 2022.