Model year for Fulbright student

A warm, Texan summer and a prestigious collaborative opportunity await PhD student David Gwyther when he takes up a Fulbright Postgraduate Scholarship at the University of Texas, Austin, in July.

David, whose research involves modelling the impact of ocean warming and circulation change on the thinning of the Totten Glacier ice shelf in East Antarctica, received his scholarship invitation at an award ceremony at Parliament House on 21 March.

The $40 000 scholarship will enable a 12 month collaboration with American scientists involved in the ICECAP project (Investigating the Cryospheric Evolution of the Central Antarctic Plate).

ICECAP is an international collaboration involving the Jackson School of Geosciences at the University of Texas, the Australian Antarctic Division, and the University of Edinburgh. Using airborne observations, ICECAP scientists aim to uncover information critical to ice sheet modelling and an understanding of the role of the East Antarctic ice sheet in global climate and sea level rise.

As one of the fastest-thinning glaciers in East Antarctica and a contributor to sea level rise, the Totten Glacier is of great interest to the ICECAP project. The glacier is thinning up to 1.9 metres per year and has undergone a three-fold increase in thinning over the past 10 years.

During his PhD research, through a CSIRO–University of Tasmania Program in Quantitative Marine Science, David has been working on an ice shelf–ocean model that models the interaction between ocean currents and the cavity under the Totten ice shelf, and calculates melt rates under different scenarios (Australian Antarctic Magazine 21: 14–15, 2011). The Totten ice shelf-ocean model builds on existing modelling capability at the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) (Australian Antarctic Magazine 19:6, 2010) and utilises supercomputer resources from the National Computing Infrastructure and the Tasmanian Partnership for Advanced Computing.

‘While we’re confident with how the model portrays the oceanography, we don’t have much information about the roughness at the base of the ice shelf, or the bathymetry of the sea floor below it,’ David says

‘This information is important because as water flows over rough surfaces it becomes more turbulent and this mixes more heat to the underside of the ice shelf, causing more melting. ‘

Fortuitously, the ICECAP team in Texas, in collaboration with the Australian Antarctic Division and the ACE CRC, has recently taken measurements of ice thickness and topography over the Totten Glacier and its ice shelf using an air-borne, ice-penetrating radar and gravimeter. These measurements will provide the roughness and bathymetry data David needs to improve his model simulations.

‘The Fulbright scholarship will allow me to take this model to Austin and incorporate the ice roughness and bathymetry observations, to better model the structure of the cavity under the ice shelf and, subsequently, how ocean currents interact with it under different climate change scenarios,’ he says.

David will also share his knowledge and experience of the model with the Austin team.

‘This model is open source but there’s a steep learning curve to using it. Once you know how to use it though, you can apply it anywhere where there is an interaction between water and another surface,’ he says.

David’s research is a far cry from the theoretical quantum optomechanics he studied as an undergraduate, although he does draw on the problem-solving and numerical computing skills he learnt at the time. His current research is taking him in quite a different direction.

‘I had a friend at university from the Polynesian nation of Tuvalu who told me that sea level rise had left his parents’ land half the size it once was,’ David says.

‘My conversations with him made me think I’d like to focus my energy on climate change research, and it changed the course of my career.’

Wendy Pyper
Australian Antarctic Division

The international Fulbright Program was established by US Senator J. William Fulbright in 1946 to facilitate world peace through cultural and educational exchange. The Australian-American Fulbright Program established in 1949 is funded by both governments, and sponsors and donors.