An earlier than usual
foray into far southern waters will help
scientists understand the connection between
Antarctic sea ice and the ecosystems that
depend on it for survival.
The voyage, to depart Hobart on September
4, is Australia's first in around 10 years
to head into the Southern Ocean while the
sea ice remains in place before the summer
thaw.
The Sea Ice Physics and Ecosystem eXperiment
(SIPEX*) voyage, jointly organised by the
Antarctic Climate & Ecosystems Cooperative
Research Centre (Antarctic CRC) and the
Australian Antarctic Division, will sail
from Hobart at the beginning of September
2007.
Eighty-six scientists from eight nations
will use a suite of cutting-edge technologies
to study processes on the sea ice surface,
as well as within and under the ice in the
region east of Australia's Casey Station.
The six-week voyage will examine interactions
between sea ice structure, sea ice biology
and the ocean food web.
Around 19 million square kilometres of
sea ice forms around Antarctica every winter,
covering an area of ocean almost three times
the size of Australia. Most of it melts
away over summer. The annual formation and
melting of sea ice plays an important role
in global ocean and climate processes as
well as the winter survival of some species
in the Southern Ocean ecosystem.
'Ice thickness is one of the big uncertainties
about sea ice dynamics,' said voyage leader
Dr Tony Worby. 'For the last 30 years or
so, satellites have allowed us to measure
the extent of sea ice over the ocean, but
current remote sensing techniques are not
effective at estimating the thickness of
the ice or the snow that accumulates on
it.'
The study will employ two new sophisticated
airborne systems that will allow researchers
to calculate the thickness of both the ice
and its snow cover.
'This will be the first time that helicopter
laser altimetry and snow radar have been
used over Antarctic sea ice,' Dr Worby said.
'The data we collect will help validate
information received from new satellite
sensors that we hope will be useful for
measuring sea ice thickness in the future.'
Sea ice also serves as a resting platform
for marine mammals and birds, and provides
a habitat for various groups of organisms
such as bacteria and algae. These algal
sea ice communities provide an important
food source for Antarctic krill and other
key species during winter and early spring.
'Longer daylight hours and melting snow
and ice during early spring cause a rapid
increase in biological activity in and under
the ice,' notes biology team leader Dr Klaus
Meiners. 'This makes it an ideal time to
study these processes.'
The biology research team will send a Remotely
Operated Vehicle (ROV) with optical sensors
under the sea ice to measure the amount
of algae within the ice and attached to
the underside of the ice. Another sensor
on the ROV will measure ice thickness. A
specially-designed trawl net will be used
to sample the environment directly under
the ice and provide live krill that can
be used for experiments in the ship's laboratories.
The sampling program will be complemented
by an extensive sea ice coring and drilling
program that will provide more data on both
the physical and biological properties of
the ice. Scientists will spend long hours
measuring snow and ice density and thickness
on drifting ice floes, as well as conducting
experiments in special freezer laboratories
on the ship.
The Antarctic CRC is creating a special
website for the voyage that will include
profiles of the scientists and their research,
daily updates from the ship, education resources
and a chance for readers to ask questions
of the researchers. Two Tasmanian school
teachers will also be on board adding their
expertise to the development of the website
materials. The website will be available
at http://www.acecrc.sipex.aq.
*SIPEX is also part of a larger International
Polar Year (IPY) research project. IPY runs
from March 2007 to March 2009 and includes
more than 200 interdisciplinary research
and education programs covering a wide range
of physical, biological and social topics
in both the Arctic and the Antarctic.
Sandra Zicus, Communications Manager, Antarctic
Climate & Ecosystems Cooperative Research
Centre
Patti Lucas, Public Affairs, Australian
Antarctic Division, +61 3 6232 3514 or 0439
639 227 after 4 Sept 2007 and during the
voyage.
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
