A secret hidden in Australia's ocean eddies

Feb 22, 2012 By Terry Clinton
Credit: Terry Clinton

Deep-diving ocean "gliders" have revealed the journey of Bass Strait water from the Tasman Sea to the Indian Ocean.

Deployed in 2010 and 2011, the gliders have also profiled a 200-metre tall wall of water at the core of long-lived eddies formed from the East Australian Current.

The study, by UTS and CSIRO , revealed the value of new sensors being deployed by Australia's Integrated Marine Observing System.

"We're getting a terrific amount of data that is opening up a very big window on Australia's oceans," UTS scientist Dr. Mark Baird said.

Dr. Baird was the lead author of a paper published this week in . Dr. Baird is a Research Fellow with the UTS Plant Functional Biology and Climate Change Cluster and a member of the C3 Coastal Oceanography Team.

"In this case, we have seen for the first time a 200-meter tall, 40 kilometer wide disc formed from water that originated in Bass Strait that amazingly remains undiluted as it travels hundreds of kilometers," he said.

Graphic developed by Louise Bell of the CSIRO

"This is a clear example of the benefits arising from a significantly enhanced technical ability to explore our oceans and identify features relevant to and climate."

Scientists have known that salty Bass Strait water, with its unique , flows into the north-east of Flinders Island, sinking to a depth of 400-800 metres in a feature referred to as the Bass Strait Cascade.

However, the porpoising action of the $200,000 pre-programmed ocean gliders has given scientists data to a depth of 1000 metres and a detailed insight into anti-clockwise rotating warm-core eddies that regulate and influence the ocean food chain.

Co-author and leader of these Integrated Marine Observing System deployments, CSIRO Wealth from Oceans scientist Ken Ridgway, said the gliders were programmed to sample across the East Australian Current and through long-lived ocean eddies up to 200 kilometres across that form off New South Wales.

"East of Tasmania, we  found bodies of water entrained in the ocean eddies that were originally formed six months previously in Bass Strait and that were up to 40 kilometres wide and 200-300 metres in height," Mr. Ridgway said.

"Further measurements show that at least some of this Bass Strait water makes the journey past southern Tasmania and possibly thousands of kilometres into the Indian Ocean."

The $230M Integrated Marine has successfully deployed a range of observing equipment in the oceans around Australia, and is making all of the data freely and openly available through the IMOS Ocean Portal for the benefit of Australian marine and climate science as a whole.

The Bass Strait study was part-funded through the Australian Climate Change Science Program, a joint initiative of CSIRO, the Bureau of Meteorology and the Department of Climate Change and Energy Efficiency with further support from the Australian Research Council and the Sydney Institute of Marine Science.

IMOS is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy and the Super Science Initiative.

Explore further: NASA sees Typhoon Matmo making second landfall in China

Provided by University of Technology, Sydney

4.5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

East Coast gliders yield valuable marine life data

Feb 28, 2011

The influence ocean eddies have on marine life in the oceans surrounding Australia’s south-east is expected to become clearer after scientists examine data from new deep-diving research ‘gliders’ ...

'Ocean glider' home after two-month voyage

Apr 16, 2009

Scientists are celebrating the first successful deployment and retrieval in Australia of a remotely controlled, deep ocean-going robotic submarine destined to play a central role in measuring changes in two ...

Deep-ocean sentinels on northern climate watch

Jul 28, 2011

Three deep-ocean moorings have become the foundation for a new drive to measure change in currents linking the Pacific and Indian Oceans through the Indonesia Archipelago – a key factor influencing Australia’s ...

Highest-ever winter water temperatures recorded

Aug 06, 2009

(PhysOrg.com) -- Tasmania’s east coast is recording its highest-ever winter water temperatures of more than 13ºC - up to 1.5ºC above normal - due to a strengthening of an ocean current originating north ...

Recommended for you

Fires in the Northern Territories July 2014

7 hours ago

Environment Canada has issued a high health risk warning for Yellowknife and surrounding area because of heavy smoke in the region due to forest fires. In the image taken by the Aqua satellite, the smoke ...

How much magma is hiding beneath our feet?

7 hours ago

Molten rock (or magma) has a strong influence on our planet and its inhabitants, causing destructive volcanic eruptions and generating some of the giant mineral deposits. Our understanding of these phenomena ...

Oso disaster had its roots in earlier landslides

10 hours ago

The disastrous March 22 landslide that killed 43 people in the rural Washington state community of Oso involved the "remobilization" of a 2006 landslide on the same hillside, a new federally sponsored geological study concludes.

User comments : 0