High-tech voyage will investigate life in the sea-ice zone
14th September 2012
For the first time under-ice and airborne vehicles will be used simultaneously to investigate the impacts of climate change on the sea ice environment off East Antarctica.
An autonomous, underwater vehicle will measure the thickness of sea ice floes while a remotely-operated robot will observe the hidden lives of algae and krill that live beneath the ice.
More than 50 scientists, from nine countries leave Hobart today aboard Australia’s icebreaker Aurora Australis to gather information critical for a greater understanding of the connection between sea ice and Southern Ocean ecosystems.
Science leader, Dr Klaus Meiners, from the Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) said there are many, integrated projects looking at the physical and biological elements of the Antarctic sea ice zone.
“Scientists will collect a range of complex measurements and data to help us understand the different processes affecting the region’s ecosystem during spring, when the sea ice is at its maximum extent.”
Dr Meiners said that while reliable data exists on the extent of sea ice cover, measuring the thickness of Antarctic sea ice had been much more difficult.
“This information is essential in providing an accurate picture of the overall changes in the amount of sea ice. Data collected during the voyage will be used to improve satellite estimates of sea-ice thickness, and to provide input to sea ice models.”
Work will begin at the sea ice edge and aim to penetrate the entire pack-ice zone towards the coastal fast ice. Multi-day research stations will be set up on suitable ice floes and GPS equipment will help with positioning the various platforms on, above and below ice that is constantly moving.
“Researchers will also be using instruments mounted in a helicopter to take ice and snow thickness measurements, and ice-core data will be collected on the surface of the ice,” Dr Meiners said.
The Australian Antarctic Division’s Acting Chief Scientist, Dr Tas van Ommen, says that Antarctic sea-ice zone is an important driver and indicator of global climate processes, with its annual freezing and melting thought to be one of the largest seasonal cycles on Earth.
Measuring the effects of climate change on sea ice is very difficult as satellite imagery mainly provides a measure of the amount of ocean the ice is covering, but gives little indication of whether the ice is thinning or changing in other important ways.
“In the Arctic there were major changes in ice thickness detected prior to the onset of the substantial reductions in sea ice we see there now each summer.
“SIPEX 2 will establish these measurements for Antarctica and help us track these changes in the future,” Dr van Ommen said.
The seven-week voyage - Sea Ice Physics and Ecosystem eXperiment (SIPEX-2) – is a continuation and extension of SIPEX-1, which took place in September-October 2007 and is jointly coordinated by the Australian Antarctic Division and ACE CRC.
SIPEX-2 - which brings together scientists from Australia, Belgium, Canada, France, Germany, Japan, New Zealand and the United States - kicks off a busy 2012/13 polar season of Australian and international collaborative research.
Around 550 expeditioners will travel south this season as part of Australia’s Antarctic program, departing Hobart for Casey, Davis, Mawson and Macquarie Island stations and remote off-station locations.
- Follow the SIPEX voyage on Dr Wendy Pyper's Blog as she travels south with the scientists.
SIPEX voyage video
Dr Klaus Meiners – Science Leader
We are leaving on a voyage which is called the Sea-ice Physics and Ecosystems Experiment. We are leaving on Friday for a 50 day trip and this voyage brings together experts from 9 countries and 17 organisations and we go out there to study the physics, the chemistry and the biology of the sea ice zone, that is the part of the Southern Ocean that is frozen.
We plan a lot of activities and we stop the ship for 2.5 days in one spot, moored to an ice floe and then have up to 40 people working on the ice doing various measurements. Then we also use underwater robots, two of them, and they look at the subsurface of the ice and do oceanographic measurements. And we use instrumented aircraft for regional scale observations of sea ice, especially sea ice thickness. And also look for Krill. Krill is a shrimp-like 5-10 centimetre long crustacean. Krill come at the end of winter under the ice and feed there and that’s critically important for the entire food web and we look at that.
Antarctic sea ice has increased over the last 3 decades by 1 percent, however this is belying really strong regional changes. For example in the West Antarctic Peninsula we have a strong decline in sea ice extent and duration and that has really strong impacts on life in the ocean. These regional changes are also occurring in the Australian Antarctic Territory off East Antarctica, we have changes in duration of the sea-ice.
One of the main questions we try to address is, we would like to learn more about the ice thickness. We have very good data from satellites on ice extent, so how much it is reaching out from the continent, but we are unable at the moment really to measure continuously changes in thickness, and so current changes could go unnoticed.