Small salty whirlpools driving Antarctic ice melt

Dr Bishakhdatta Gayen standing beside the Derwent River in Hobart.
Australian National University geophysicist and RJL Hawke Post-Doctoral Fellow, Dr Bishakhdatta Gayen, aims to define the boundary layer between the ocean and Antarctic ice sheet, to improve ocean model estimates of ice melt and sea level changes. (Photo: Wendy Pyper)
Front of the Totten Glacier in East Antarctica.A schematic of the ocean circulation on the Antarctic continental shelf.

8th September 2017

The role that small salty whirlpools play in melting the Antarctic ice sheet will be the focus of a new Antarctic Environmental Science Fellowship.

Australian National University (ANU) researcher, Dr Bishakhdatta Gayen, has been awarded the third Australian Government RJL Hawke Post-Doctoral Fellowship.

Dr Gayen’s work will look at the millimetre-thick ‘boundary layer’ of salty water between the Southern Ocean and the bottom of the Antarctic ice sheet.

“While this layer is tiny, it could provide the key to more accurate projections of ice melt and future sea level change,” Dr Gayen said.

At the boundary layer, salt and heat from the ocean interact with the bottom of the ice shelf around the Antarctic continent, causing the ice to melt.

This fresh meltwater is often unstable and turbulent, producing tiny whirlpools of water thought to boost the rate of melting.

“These complex boundary layer dynamics and heat transfer processes will be the focus of my research over the next two years,” Dr Gayen said.

“I will use a supercomputer to develop a mathematical relationship between melt rate and turbulence, which can be scaled up to represent ocean-wide processes in models.”

Data generated by these ice melt simulations will be validated by experiments in the ANU’s Geophysical Fluid Dynamics laboratory.

“It’s really exciting to be able to undertake this research because we have to understand what’s happening at the millimetre scale of the boundary layer, to really understand the changing nature of ice sheets across the entire continent,” Dr Gayen said.

The RJL Hawke Postdoctoral Fellowship was named in honour of former Australian Prime Minister Bob Hawke, acknowledging his contribution to protecting the Antarctic environment. The fellowship is awarded on the basis of scientific excellence for early career doctoral graduates to pursue policy-relevant science aligned to the Australian Antarctic Science Plan. 

Other Hawke Fellowship projects