Dr Tas van Ommen - ice core palaeoclimate scientist
Dr Tas van Ommen – Climate Processes and Change Theme Leader
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.
Dr Tas van Ommen: PhD, BSc(Hons), Dip. Teach.
Program Leader: Antarctica and the Global System
My main research interests centre around ice core palaeoclimate studies, particularly high resolution palaeoclimate work extending back into the last glacial period. Our ice core group has done much of its work on the deep, high resolution Law Dome core which extends back approximately 90 000 years. The group is also involved in obtaining century-scale records from relatively near-coastal sites that give high resolution records like Law Dome.
Our work aims to provide detailed climate reconstructions and obtain calibrations for ice core data streams against modern meteorological data. We are interested in probing high and mid-latitude climate in the Indian Ocean and Australian sector particularly. This includes work to develop longer term climate reconstructions for the Australian region.
I am involved, through the International Partnerships in Ice Core Sciences (IPICS), in developing plans for recovering the oldest ice from the Antarctic ice sheet. As part of this interest, I am a lead investigator in the ICECAP airborne geophysical survey work covering East Antarctica out of Casey. This work involves collaboration with ice sheet dynamics researchers to link ice sheet dynamics and ice core data, to identify potential locations where oldest ice might be located, and to understand the history and evolution of the ice sheet (see related article Australian Antarctic Magazine 28:13-15, 2015).
National and international representation/collaborations
- Chair of the Australian Academy of Science National Committee for Earth System Science.
- SCAR Steering Committee member - Antarctica and the global climate system program.
- Secretary of the SCAR Standing Scientific Group on Physical Sciences.
- Australian representative on the International Partnerships in Ice Core Sciences (IPICS) steering committee.
- Member of the IPICS steering committees for Oldest Ice and 2000-year Array projects (aimed at constructing climate records of the last two millennia).
- Contributing author and expert reviewer for the Intergovernmental Panel on Climate Change (IPCC).
- Collaborations with groups in the United States, Denmark, Italy and France and strong links with Japan, and through IPICS, to the broader ice core community.
- Climate change: cold, hard facts on a hot topic (Australian Antarctic Magazine 9: 2-4, 2005)
- Sea levels rise as Antarctic snow falls short (Australian Antarctic Magazine 11: 30, 2006)
- Is snowfall in Antarctica linked to rainfall in Australia? (Australian Antarctic Magazine 13: 22, 2007)
- Antarctic ice cores shed light on Western Australian drought (AAM 18, 2010)
van Ommen T. (2015). Palaeoclimate: Northern push for the bipolar see-saw, Nature 520 (7549) 630-631. doi:10.1038/520630a. [AAS Projects 4061]
Roberts J., Plummer C., Vance T. et al (2015). A 2000-year annual record of snow accumulation rates for Law Dome, East Antarctica, Climate of the Past 11 (5). 697-707. doi:10.5194/cp-11-697-2015. [AAS Projects 757, 4061, 4062]
Greenbaum J.S., Blankenship D.D., Young D.A.et al (2015). Ocean access to a cavity beneath Totten Glacier in East Antarctica. Nature Geoscience 8: 294-298. doi:10.1038/ngeo2388. [AAS Projects 4077]
Vance T.R., Roberts J.L., Plummer C.T. et al. (2015). Interdecadal Pacific variability and eastern Australian megadroughts over the last millennium. Geophysical Research Letters 42. 129-137. doi:10.1002/2014GL062447. [AAS Projects 4061]
Young D.A., Lindzey L.E., Blankenship D.D. et al. (2015). Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet. Journal of Glaciology 61 (225): 17-28. doi:10.3189/2015JoG14J048. [AAS Projects 3103, 4077]
For more of Dr van Ommen's publications see Google Scholar.