Australia Uses Lasers to Check Antarctic Sea Ice
There are concerns that Antarctic sea ice might be getting
thinner, the Australian Antarctic Division said in a statement
Sea ice plays an essential role in regulating global
climate as well as supporting the Southern Ocean ecosystem.
Sea ice could be expected to respond to global warming and
was therefore like a canary in a coal mine, said Australian
glaciologist Tas van Ommen.
The ice is also highly reflective of sunlight. Less ice
would directly cause heating of the Southern Ocean, he said.
Loss of sea ice could also slow deep, cold briny currents
that drive the circulation of the oceans, he said.
The six-week international expedition aboard the Antarctic
research ship Aurora Australis, now in the Southern Ocean, is
using two helicopters equipped with laser altimetry equipment
to measure 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.
Prior to this experiment, very few measurements had been
made and any changes might have gone unnoticed, said expedition
leader Dr Tony Worby of Australia's Antarctic Climate and
Ecosystems Cooperative Research Centre.
"The laser work we are doing is going particularly well. We
are collecting excellent data which we expect will considerably
improve our knowledge of sea ice in this region of Antarctica,"
The ultimate aim of the helicopter altimetry, combined with
the surface measurements, is to help validate and improve
measurements from satellites. These can then be used to
estimate Antarctic sea ice thickness over large areas, the
Australian Antarctic Division said.
While laser altimetry has been used in the Arctic, it is
the first time it has been tested in the Antarctic.