CAPT. Ewald Brune knows the moods of the Southern Ocean.
"It can be as flat as a millpond or as stormy as a hurricane,"
says the veteran of 12 years of Southern Ocean voyaging. And, when
it's in a rage, he admits, "It's the worst weather in the world."
Fisherman Malcolm Hart of the village of Strahan, on Tasmania's
west coast, says an oil rig exploring off Tasmania's west coast had
barrels swept off its deck by high seas. The deck was 90 feet above
the surface of the ocean. Mr. Hart says a research buoy off the
coast has recorded swells of up to 108 feet.
"Oh, you have to watch the weather," says Mr. Hart, who has
fished the Southern Ocean for 30 years.
During the winter, about a third of the Southern Ocean is covered
by sea ice as Antarctica's extent doubles from its summer size. The
ice can pose even more dangers than the waves. This year, South
African sailor John Martin had to abandon his $1 million sailboat
after hitting a "growler," a broken-up iceberg, in the Southern
The Southern Ocean, containing about 10 percent of the world's
ocean water, covers less area than the Indian, Atlantic, or Pacific
Oceans, each of which it joins. But scientists are now discovering
that the Southern Ocean is an integral part of the earth's
circulation and climate system.
"It is like an oceanic conveyor belt where you have cold and
saline antarctic waters sinking to the bottom. This cold water then
flows north well into the northern hemisphere where it 'upwells' and
you have warmer water flowing south," says Harvey Marchant, a
principal research scientist at the Australian Antarctic Division,
based in Hobart. This, in effect, regulates the temperature of the
"So even though it is only 10 percent of the world's oceans, it
has a much larger effect," says Dr. Marchant.
Unlike the Arctic Ocean, which is not very deep and virtually
surrounded by land, the Southern Ocean is deep, surrounding a
continent the size of Australia. The Arctic is less saline since it
is fed by large rivers in North America and Asia.
In addition, the Southern Ocean has the world's largest currents.
Even though they only move at one to two knots, they are massive,
says John Church, a scientist at the Commonwealth Scientific and
Industrial Research Organization's (CSIRO) Division of Oceanography.
He estimates the Southern Ocean currents move about 130 million
cubic feet of water per second. By way of comparison, all of the
world's rivers combined carry 1 million cubic feet of water per
This September scientists from the Antarctic Division and CSIRO
will board the 18-month-old research vessel Aurora Australis to try
to better understand how these currents transport heat and salt and
fresh water. The vessel will measure the entire water column every
30 miles from Tasmania to the ice encompassing Antarctica. Some
instruments are designed to be left behind for future monitoring.
Scientists will focus their measurements on the amount of carbon
in the water. This will allow them to calculate the amount of carbon
dioxide absorbed into the Southern Ocean.
Researchers believe the Southern Ocean absorbs more carbon
dioxide than it releases. …