http://www.ens-newswire.com/ens/sep2006/2006-09-27-01.asp

Warm Water Surging into Arctic Ocean

FAIRBANKS, Alaska, September 27, 2006 (ENS) - Surges of warm water

from the North Atlantic Ocean are flowing into the Arctic Ocean and

could accelerate the melting of Arctic sea ice, according to

scientists at the International Arctic Research Center (IARC). The

influx of warmer water is increasing, the researchers said Tuesday,

and is moving toward Alaska and the Canadian Basin.

The scientists made the observations this fall during an oceanographic

cruise aboard a Russian icebreaker as part of the Nansen and Amundsen

Basins Observational Systems (NABOS) program. During the last decade

the program, along with other research, has shown a steady increase in

the movement of warm water into the Arctic Ocean. The readings from

this year show unprecedented warmth in some areas, the researchers said.

"The large area of the Arctic Ocean promises to become much warmer,"

said Igor Polyakov, NABOS principal investigator and a research

professor at IARC.

The readings come from observational moorings, which are

instrument-bearing buoys that are anchored to the ocean floor and

float below the surface of the ocean.

The instruments first detected a surge of abnormal warm water, at

mid-ocean depths of about 150 to 800 meters below the surface in

February 2004 on the continental slope of the Laptev Sea, north of

Siberia. ice

Sea ice is disappearing in the Arctic Ocean at unprecedented rates.

(Photo courtesy Arctic Coring Expedition)

"What we found this year was one of our eastern moorings also showed a

warming signal," Polyakov explained.

That finding indicates that the warm water is moving further and

further into the Arctic, Polyakov said, a trend that could increase

the overall temperature of the Arctic Ocean.

The researchers note that the causes of the influx of warm water will

require further study, but say the observations suggest that the

Arctic Ocean is moving toward a warmer state, a change that could have

global implications.

Ocean temperature in the Arctic is important because it may affect the

amount of sea ice in the region. Scientists believe that Arctic sea

ice cover plays a major role in the global climate, as ice reflects

more of the sun's heat than open water.

Recent research has shown dramatic increases in Arctic sea ice melt,

but has also shown that the average temperature of the upper oceans

has cooled significantly since 2003. But the findings are not as

contradictory as they might seem.

The study of ocean temperatures, released last week, "suggests global

warming isn't always steady but happens with occasional 'speed

bumps'," said coauthor Josh Willis, a scientist at NASA's Jet

Propulsion Laboratory.

"This cooling is probably natural climate variability," Willis said.

"The oceans today are still warmer than they were during the 1980s,

and most scientists expect the oceans will eventually continue to warm

in response to human-induced climate change."

The study found that the average temperature in the upper 2,500 feet

of Earth's oceans - an area that represents about 20 percent of the

global ocean's average depth - fell 0.055 degrees Fahrenheit from 2003

to 2005.

The recent decrease is a dip equal to about one-fifth of the heat

gained by the ocean between 1955 and 2003, but the decline is a

fraction of the total ocean warming seen over the previous 48 years,

according to the study.

The findings have significant implications for global sea-level rise,

Willis added.

Average sea level goes up partly due to warming and thermal expansion

of the oceans and partly due to runoff from melting glaciers and ice

sheets, he explained, and the recent cooling episode suggests that sea

level should have actually decreased in the past two years.

"Despite this, sea level has continued to rise," Willis said. "This

may mean that sea level rise has recently shifted from being mostly

caused by warming to being dominated by melting. This idea is

consistent with recent estimates of ice-mass loss in Antarctica and

accelerating ice-mass loss on Greenland."

Environment News Service (ENS) 2006.