The processes and composition of the Southern Ocean will be under scrutiny during a north-south ocean transect between Tasmania and Antarctica beginning early next month.

An Australian marine science voyage into the Southern Ocean gets under way tonight (Monday 29 October) when the ice research ship Aurora Australis leaves Hobart for the major marine science cruise of the summer.

During the five week voyage the ship will be a platform for marine science investigations into:

  • changes in global climate, taking advantage of the greater sensitivity of the ocean to subtle changes undetectable on land. Data will be compared to previous transect information to determine changes over the past few years
  • distribution, growth and animal consumption of phytoplankton (single-celled ocean plants) to determine their role in moderating climate change by taking in carbon dioxide and in transferring carbon to the deep ocean, along with other studies of the oceanic carbon cycle
  • sinking biological particles in the open ocean, detected by mooring deep-ocean buoys with automated 'traps’ to obtain a week by week record, to be analysed on later recovery of the buoys
  • iron distribution and its effect on the growth of phytoplankton in the seasonal sea ice zone around Antarctica
  • the extent to which natural trace gases, including methyl bromide, affect depletion of ozone in the upper atmosphere.

Aurora Australis is scheduled to depart Macquarie Wharf no. 4, Hobart, at 5 pm Monday 29 October 2001. It is due back in Hobart on 14 December 2001.