CSIRO and Antarctic Climate & Ecosystem CRC’s Dr Steve Rintoul explaining to media to links between science undertaken on Sir Douglas Mawson’s voyage south 100 years ago and the voyage that left Hobart on January 5, 2012.

CSIRO and Antarctic Climate & Ecosystem CRC's Dr Steve Rintoul explaining to media to links between science undertaken on Sir Douglas Mawson's voyage south 100 years ago and the voyage that left Hobart on January 5, 2012.

Looking for climate clues in the Southern Ocean

Scientists have left on a research voyage to the Southern Ocean to investigate how the Southern Ocean is changing and to discover what impact those changes will have on climate, sea level, and marine life.

  • 5 January 2012

The Australian Antarctic Divison's Aurora Australis has set sail from Hobart with a complement of 50 scientists and support staff for the month-long voyage to Commonwealth Bay, the Ross Sea and return to Fremantle.

Voyage Leader, Dr Steve Rintoul, said current meter moorings deployed two years ago would be retrieved. The mooring’s sensors have been measuring the speed, temperature and salinity of the coastal currents adjoining the Antarctic continental shelf.

"These measurements, the first of their kind in this part of the ocean, will allow us to discover how the deep ocean around Antarctica is changing and how these changes are spreading north into the other ocean basins," Dr Rintoul said.

Dr Rintoul, an oceanographer with CSIRO and the Antarctic Climate & Ecosystem Cooperative Research Centre (CRC), said recent studies suggest that some of the strongest climate change signals are already underway in the high latitudes.

"The Southern Ocean is warming more rapidly than the global average and increased rainfall and ice melt has caused widespread freshening of the upper and deep layers of the Southern Ocean.Dr Steve Rintoul assesses the multi-year ice during Aurora Australis' January, 2011 marine science voyage.

"The Southern Ocean helps to slow the rate of climate change by absorbing large amounts of heat and carbon dioxide.  A key goal of our work is to determine if the Southern Ocean will continue to play this role in the future."

The team will measure changes in temperature, salinity, carbon dioxide, oxygen and nutrients between Casey station and Fremantle. The measurements are collected using a profiler that is lowered from the ship down to the sea floor, to depths of more than 5 km.

Other projects to be carried out on the voyage include:

  • sampling of Southern Ocean zooplankton to see if acidification of the ocean caused by carbon dioxide emissions is affecting their ability to form shells
  • deployment of new profiling floats that can sample ocean currents in the sea ice zone during winter when the region is usually inaccessible
  • novel metagenomic studies that will collect fragments of DNA from sea water to determine how the physical environment influences the distribution and function of microbes
  • mapping biodiversity of plankton in the Southern Ocean, and continuing to build on the life history information of the krill fishery, the largest Antarctic fishery.

Aurora Australis is scheduled to return to Fremantle on February 8, 2012.

Listen to the podcast, 'Scientists set sail south in search of climate evidence'.