Greenland’s Melting Ice Could Slow Ocean Circulation

The flow of water from Greenland’s melting ice sheet is adding freshwater to the North Atlantic Ocean and could disrupt a movement of water that contributes to global ocean currents and influences regional climates, according to a new study published in Nature Communications.

Greenland’s rapidly melting ice sheet could slow down the Atlantic Meridional Overturning Circulation (AMOC) and lead to cooler winters and summers in the North Atlantic region, and small increases in sea level along the North American coast, according to a story in Newsweek.

The flux of water coming from Greenland’s ice sheet was stable from the late 1970s to the mid-1990s, but has been on the rise as the runoff from melting ice and calving of icebergs has increased. Most of this water ends up in the Labrador Sea because of the clockwise circulation around Greenland, according to a press release issued by the University of South Florida.

“The data suggest that the influx of freshwater from Greenland is accelerating, and has changed the Labrador Sea in ways that could lead to a weakening of the AMOC,” said Tim Dixon, a professor at the University of South Florida and one of the study’s authors.

The AMOC moves heat from the tropics and the southern hemisphere into the North Atlantic, where it is released into the atmosphere. It helps regulate the climate in North America and Europe.

Eastern Canadian Arctic Cools as Rest of the World Warms

While record-setting temperatures were seen throughout most of the world last year, parts of the Arctic in eastern Canada were cooler than average, CBC News reported.

The temperature anomaly in Northern Quebec, Labrador, parts of Nunavut and southern Greenland stood out in a report released by NASA and the U.S. National Oceanic and Atmospheric Administration last week. It showed that 2015 was by far the hottest year for the planet on record.

The reasons behind the cold spot have yet to be determined, but it could be related to increased melting in Greenland and a slowdown of the AMOC, according to the story.

Climate models that show a “cold blob” in the subpolar Atlantic and near the southern coast of Greenland and warming along the U.S. east coast are characteristic of a slowdown of the AMOC, according to RealClimate. The sea surface conditions of the “cold blob” were colder in 2015 than any other year since records began in 1880.

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Top image: Frozen meltwater lake along the northeast Greenland coast. (NASA/Jim Yungel)