Aug. 21, 2007 — Australian climate scientists have located a deep-ocean current in the Tasman Sea that may play a big role in connecting the world's oceans, and therefore regulating Earth's climate.
The newfound Tasman Outflow is part of the "super-gyre" ocean current pathway which helps connect the Indian, South Atlantic and South Pacific oceans and is part of the global heat conveyor belt known as the thermohaline circulation. It's not certain, however, just how big a player the Tasman Outflow is.
"It's another link between the Pacific and Indian Ocean," said Ken Ridgway of the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO). "The other is through Indonesia." Ridgway and his colleagues report on the Tasman Outflow in the August issue of Geophysical Journal Letters.
"What we've been really able to show is the pathway and define the very narrow boundary current," said Ridgway. "It's these boundary flows that connect everything up."
Ridgway describes the Tasman Outflow as a current that runs west from Tasmania at a depth of 2,600 to 3,300 feet (800 to 1,000 meters). He also describes the waters south of Tasmania as a "choke-point" in the connections between southern oceans.
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In the broader picture in which each ocean contains giant "gyres" of currents, the Tasman Outflow is a small eddy, or spin off, that carries Pacific water from the Coral Sea down the east coast of Australia and then away to the Indian Ocean. It was identified by crunching a large amount of temperature and salinity data collected by ships, buoys and satellites from 1950 to 2002.
