Ocean's 'missing link' discovered
Posted: Thu Aug 16, 2007 9:56 pm
Australian scientists have discovered a giant underwater current that is one of the last missing links of a system that connects the world's oceans and helps govern global climate.
New research shows that a current sweeping past Australia's southern island of Tasmania toward the South Atlantic is a previously undetected part of the world climate system's engine-room, said scientist Ken Ridgway.
The Southern Ocean, which swirls around Antarctica, has been identified in recent years as the main lung of global climate, absorbing a third of all carbon dioxide taken in by the world's oceans.
"We knew that they (deep ocean pathway currents) could move from the Pacific to the Indian Ocean through Indonesia. Now we can see that they move south of Tasmania as well, another important link," Ridgway, of the Commonwealth Scientific and Industrial Research Organisation, told Reuters.
Earlier this year, another CSIRO scientist said global warming was already having an impact on the vast Southern Ocean, posing a threat to myriad ocean currents that distribute heat around the world.
Melting ice-sheets and glaciers in Antarctica are releasing fresh water, interfering with the formation of dense "bottom water", which sinks 4-5 kilometers to the ocean floor and helps drive the world's ocean circulation system.
A slowdown in the system known as "overturning circulation" would affect the way the ocean, which absorbs 85 percent of atmospheric heat, carries heat around the globe, Steve Rintoul, a senior scientist at the CSIRO Division of Marine and Atmospheric Research, said in March
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