Climate research

Dr Tas van Ommen – Climate Processes and Change Theme Leader

Video transcript

Dr Tas van Ommen — Climate Processes and Change Theme Leader

I am a physicist by training. I started my research career as an astronomer and worked overseas for a while, came back to Australia and fell sideways into a position here at the Antarctic Division doing the physics of glaciers, so I have become a glaciologist in my career.

So the Climate Processes and Change theme covers four areas. The first of those is the ice sheet itself, the second area is the ice that floats on the ocean and oceanography all wrapped up into super sub-theme. The third area we look at is the atmosphere above Antarctica and the fourth strand to our research is looking at past climate mainly from looking at ice cores that go back in time.

Looking back in the past is really the only way you can get enough information to test your understanding of the way the climate system works. And we’ve used the really detailed ice cores that we get from Law Dome, which is near Casey station, and they’ve allowed us to look in great detail at climate change and understand it in a way that you can’t do from most ice-cores just because of this high detail.

For example we have looked at changes in snow fall in the area over the last several centuries. We’ve found quite a clear link between rainfall in Western Australia or the drought that has been there and snowfall in East Antarctica. We’ve been able to use the very long records from the ice cores to say that what we are seeing now is unusual and very likely connected to climate change itself.

One of the projects I have been involved in actually was looking with a plane that has radar under the wings, shining the radar through the ice sheet to actually get a map of the bedrock underneath. And that was fascinating because we were flying along looking at the computer traces coming back from the radar and seeing for the first time the way the bedrock had deep valleys and high mountains underneath and for the first time being able to map out large areas of Antarctica.

There are still really important questions to answer about where Antarctica and the climate system is headed. We need to understand better for example how the ice sheets are going to respond in a warming climate because any loss of the ice in the Antarctica translates to sea level rise.

One of the highlights of this career is being able to actually go into the field and do some research. Drilling for an ice core where you might be hundreds of kilometers away from the nearest other party of human beings in extreme environments, experiencing the almost sensory overload of the wind, the cold, and the stunning visual environment that you are in, it’s really invigorating.

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Where ice and ocean meet, Sørsdal Glacier
Sørsdal Glacier (Photo: Barbara Wienecke)
Dr Tas van Ommen in the field wearing a yellow Antarctic Division jacket.Schematic of the Southern Ocean overturning circulationDeploying one of the large yellow buoys on a sub-surface mooring during a marine science voyage. (Photo: Wendy Pyper)An Automatic Weather Station at Casey

Climate research through the Australian Antarctic Science Program investigates the role of Antarctica and the Southern Ocean in the global climate system, building on more than 50 years of climate research in Antarctica.

The main focus of the research is to address uncertainties identified in the Fourth Assessment Report (2007) of the Intergovernmental Panel on Climate Change (IPCC). This report highlighted the lack of climate data from the Southern Ocean, the sea ice zone and Antarctica in general. It also noted a need for greater understanding of the role the region may have in slowing the rate of climate change and of the future behaviour of the ice sheet and its contribution to sea level rise.

Our climate research contributes to the IPCC’s update on the state of climate change through the Fifth Assessment Report in 2013–14 and to other assessments that may follow. It also feeds into Australia’s national priority areas for action, to manage climate change impacts and develop adaptation and mitigation strategies for climate change.

The research is conducted the following key areas:

Research questions to be investigated include:

  • What are the processes controlling ice loss from the ice sheet in both East and West Antarctica, and how will these influence future sea level rise?
  • Is the ‘global overturning circulation’ (circulation of the world’s oceans) likely to change with future warming, and what impact will this have?
  • How much heat and carbon will the Southern Ocean be able to take up and store in the future?
  • Is the development of better climate system models inhibited by poor understanding of certain high latitude (polar) atmospheric processes?
  • What can the record of past climates tell us about current and future climate change?
  • What are the ecological responses of Southern Ocean ecosystems to the impacts of global change?

Read more about climate research in the Science Strategic Plan.