Greenland Sea undergoing rapid warming: new research

This map shows the location of the Greenland Sea off the northeeastern coast of Greenland. (IMAGE COURTESY OF THE ALFRED WEGENER INSTITUTE)

This graph shows the warming trend from 1950 to 2009 (red line). The shading shows the range of temperature from 2000 m (warmer limit) to the bottom (colder limit). (IMAGE COURTESY OF THE ALFRED WEGENER INSTITUT) Source: Alfred-Wegener-Institut

Newly-published research shows that the deep Greenland Sea is warming 10 times faster than the world’s other oceans.

Between 1950 and 2010, scientists from the Alfred Wegener Institute’s Helmholtz Centre for Polar and Marine Research in Germany analysed temperatures in the depths of the Greenland Sea, an area just to the south of the Arctic Ocean.

And since 1993, oceanographers from the centre have worked aboard the research ice breaker Polarstern to investigate the changes in the region.

This is what they found: that during the last 30 years, the water temperature between 2,000 metres (6,561 feet) depth and the sea floor has risen by 0.3 C.

“This sounds like a small number, but we need to see this in relation to the large mass of water that has been warmed,” Raquel Somavilla Cabrillo, said in a Sept. 25 news release about the researchers’ findings, recently published in the journal Geophysical Research Letters.

“The Greenland sea is just a small part of the global ocean,” Cabrillo said. “However, the observed increase of 0.3 degrees in the deep Greenland sea is 10 times higher than the temperature increase in the global ocean on average.”

Until the early 1980s, the central Greenland sea had been mixed from the top to the bottom by winter cooling at the surface making waters dense enough to reach the sea floor and keep the water cool.

“This transfer of cold water from the top to the bottom has not occurred in the last 30 years,” Somavilla said. “However, relatively warm water continues to flow from the deep Arctic Ocean into the Greenland Sea.

“Cooling from above and warming through inflow are no longer balanced, and thus the Greenland Sea is progressively becoming warmer and warmer.”

Scientists say they need long-term observation on the Arctic Ocean to understand how the world’s oceans reacts to climate change.

That echoes the findings from the International Climate Change Panel report, “Climate Change 2013: the Physical Science Basis, released Sept. 27 which says “it is virtually certain” that the upper ocean has also warmed from 1971.