MEDIA RELEASE
Media Release,
20 September 2007

Sea ice under scrutiny from space

Lasers from helicopters and space satellites are being used in Antarctica, for the first time, to determine whether sea ice in the Southern Ocean is changing in response to climate change.

Sea ice plays an essential role in regulating global climate as well as supporting the Southern Ocean ecosystem, and there are concerns that Antarctic sea ice may be getting thinner.

A team of international researchers, led by the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), is on a six-week expedition in the Southern Ocean aboard the Antarctic research ship Aurora Australis, which left Hobart earlier this month.

Two helicopters equipped with laser altimeters are taking measurements of sea ice thickness. These will be tested against satellite-based measurements, taken as part of a separate US National Aeronautics and Space Administration (NASA) ICESat science project.

The ultimate aim of the helicopter altimetry, combined with surface measurements taken by scientists on the ice, is to help validate measurements from satellites. These can then be used to estimate Antarctic sea ice thickness over large areas.

Voyage leader Dr Tony Worby said that to date relatively few measurements of Antarctic sea ice thickness have been made, meaning that any variations related to recent climate change may have been going unnoticed.

While laser altimetry has been used in the Arctic, it is the first time it has been tested in the Antarctic.

The lasers provide a direct estimate of how much ice and snow is above the water level and, combined with the surface measurements, the data will help us validate and improve satellite measurements of Antarctic sea ice thickness over large areas.

"We are collecting excellent data which we expect will considerably improve our knowledge of sea ice in this region of Antarctica, and it should give us the tools to monitor whether Antarctic sea ice is changing over coming years," Dr Worby said.

The Sea Ice Physics and Ecosystems eXperiment (SIPEX) research is an international project jointly organised by the ACE CRC and the Australian Antarctic Division. It involves 45 researchers from ten different countries and is part of a larger International Polar Year (IPY) project investigating sea ice in the Antarctic.

SIPEX is also investigating the interactions between sea ice structure, sea ice biology and the ocean food web. The expedition will return to Hobart on 17 October.

Voyage website: www.acecrc.sipex.aq

For more information contact:
Patti Lucas, Australian Antarctic Division, (03) 6232 3514 or 0439 639 227




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Antarctic Climate & Ecosystems Cooperative Research Centre (Antarctic CRC)
The Antarctic CRC is a partnership dedicated to the study of atmospheric and oceanic processes of Antarctica and the Southern Ocean, their role in global and regional climate change, and their impact on sustainable management of Antarctic marine ecosystems. The Antarctic CRC works closely with Australian and international stakeholders to ensure that the research focus remains relevant and the results are made accessible in useful forms.
The Antarctic CRC does research in five interconnected program areas:
Climate Variability & Change - Improving our ability to predict the impact of Southern Ocean processes on climate, sea level, marine ecosystems and the marine carbon cycle.
Ocean Control of Carbon Dioxide - Determining carbon dioxide uptake and its effects on the ocean, and relating ocean processing of carbon dioxide to predictions of human-induced global change.
Antarctic Marine Ecosystems - Exploring relationships among the biological patterns and processes of the marine ecosystems around East Antarctica and relating them to physical oceanographic processes to predict likely ecosystem impacts of climate change and assist in development of sustainable management strategies.
Sea-level Rise - Improving our ability to project and respond to future changes in sea level by increasing our understanding of historical sea-level change, documenting the factors that contribute to changes in sea level, and assessing likely impacts of rising sea level on Australian coasts.
Policy - Providing analyses of possible policy implications arising from the science research programs and addressing issues that will help Australia formulate its input to Antarctic and Southern Ocean affairs and manage its interests in the region.
Core Partners
Australian Antarctic Division
Australian Bureau of Meteorology
CSIRO (Marine & Atmospheric Research)
University of Tasmania

Supporting Partners
Alfred Wegener Institute for Polar and Marine Research
Australian Greenhouse Office
Australian National University
National Institute of Water and Atmospheric Research
Silicon Graphics International
Tasmanian Department of Economic Development