A team of scientists from the United Kingdom has spotted the equivalent of smoke-rings in the Earth’s southern oceans which they think could ‘suck-up’ small fish and other creatures and carry them at high speed and for long distances


NASA’s SeaWiFS satellite photographed this eddy field in the waters around Tasmania in November 2000. Image credit: NASA.

The Earth’s oceans are full of eddies, swirling motions some tens to hundreds of miles across, which mix the water and carry it across the average currents.

The so-called ‘smoke-rings’ are a pair of linked eddies spinning in opposite directions that travel up to ten times the speed of ‘normal’ eddies.

They were spotted in the Tasman Sea, off the southwest of Australia and in the South Atlantic, west of South Africa.

“What we found was a pair of eddies spinning in opposite directions and linked to each other so that they travel together all the way across the Tasman Sea, taking six months to do it,” said Professor Chris Hughes, a researcher at the University of Liverpool and the lead author of a paper in the journal Geophysical Research Letters.

“Ocean eddies almost always head to the west, but by pairing up they can move to the east and travel ten times as fast as a normal eddy, so they carry water in unusual directions across the ocean.”

“The smoke-rings are cut in half by the sea surface, so we see the two ends of the half ring at the surface,” he added.

Professor Hughes and his colleague, Dr. Peter Miller from Plymouth Marine Laboratory, discovered these dipole eddy pairs by analyzing sea level measurements taken from satellites together with sea surface temperature images from the same time and place.

“The smoke-rings require an area of calm water to ‘puff’ out through, which itself is quite unusual,” Professor Hughes said.

“We’ve looked at other areas of other oceans but we’ve only seen them in the oceans around Australia, plus one in the South Atlantic.”

“Our thinking is that these linked, fast moving eddies could ‘suck-up’ small marine creatures and carry them at high speed and for long distances across the ocean.”